titanium alloys. The use of titanium metal in industry and construction

19.10.2019

Physical and chemical properties of titanium, obtaining titanium

The use of titanium in pure form and in the form of alloys, the use of titanium in the form of compounds, the physiological effect of titanium

Section 1. History and occurrence of titanium in nature.

Titan -This an element of a secondary subgroup of the fourth group, the fourth period of the periodic system of chemical elements of D. I. Mendeleev, with atomic number 22. The simple substance titanium (CAS number: 7440-32-6) is a light metal of silver-white color. It exists in two crystalline modifications: α-Ti with a hexagonal close-packed lattice, β-Ti with a cubic body-centered packing, the temperature of the polymorphic transformation α↔β is 883 °C. Melting point 1660±20 °C.

History and presence in nature of titanium

Titan was named after the ancient Greek characters Titans. The German chemist Martin Klaproth named it this way for his personal reasons, unlike the French, who tried to give names in accordance with the chemical characteristics of the element, but since the properties of the element were unknown at that time, such a name was chosen.

Titanium is the 10th element in terms of number of it on our planet. The amount of titanium in the earth's crust is 0.57% by weight and 0.001 milligrams per 1 liter of sea water. Titanium deposits are located on the territory of: the Republic of South Africa, Ukraine, Russia, Kazakhstan, Japan, Australia, India, Ceylon, Brazil and South Korea.

In terms of physical properties, titanium is a light silvery metal, in addition, it is characterized by high viscosity during machining and is prone to sticking to the cutting tool, so special lubricants or spraying are used to eliminate this effect. At room temperature, it is covered with a translucent film of TiO2 oxide, due to which it is resistant to corrosion in most aggressive environments, except for alkalis. Titanium dust has the ability to explode, with a flash point of 400 °C. Titanium shavings are flammable.

To produce pure titanium or its alloys, in most cases, titanium dioxide is used with a small number of compounds included in it. For example, a rutile concentrate obtained by beneficiation of titanium ores. But the reserves of rutile are extremely small, and in connection with this, the so-called synthetic rutile or titanium slag, obtained during the processing of ilmenite concentrates, is used.

The discoverer of titanium is considered to be 28-year-old English monk William Gregor. In 1790, while conducting mineralogical surveys in his parish, he drew attention to the prevalence and unusual properties of black sand in the valley of Menaken in the south-west of England and began to explore it. In the sand, the priest found grains of a black shiny mineral, attracted by an ordinary magnet. Obtained in 1925 by Van Arkel and de Boer by the iodide method, the purest titanium turned out to be a ductile and technological metal with many valuable properties, which attracted the attention of a wide range of designers and engineers. In 1940, Croll proposed a magnesium-thermal method for extracting titanium from ores, which is still the main one at the present time. In 1947, the first 45 kg of commercially pure titanium were produced.

In Mendeleev's periodic system of elements, titanium has serial number 22. The atomic mass of natural titanium, calculated from the results of studies of its isotopes, is 47.926. So, the nucleus of a neutral titanium atom contains 22 protons. The number of neutrons, that is, neutral uncharged particles, is different: more often 26, but can vary from 24 to 28. Therefore, the number of titanium isotopes is different. In total, 13 isotopes of element No. 22 are now known. Natural titanium consists of a mixture of five stable isotopes, titanium-48 is the most widely represented, its share in natural ores is 73.99%. Titanium and other elements of the IVB subgroup are very similar in properties to the elements of the IIIB subgroup (scandium group), although they differ from the latter in their ability to exhibit a large valency. The similarity of titanium with scandium, yttrium, as well as with elements of the VB subgroup - vanadium and niobium, is also expressed in the fact that titanium is often found in natural minerals together with these elements. With monovalent halogens (fluorine, bromine, chlorine and iodine), it can form di-tri- and tetra compounds, with sulfur and elements of its group (selenium, tellurium) - mono- and disulfides, with oxygen - oxides, dioxides and trioxides.

Titanium also forms compounds with hydrogen (hydrides), nitrogen (nitrides), carbon (carbides), phosphorus (phosphides), arsenic (arsides), as well as compounds with many metals - intermetallic compounds. Titanium forms not only simple, but also numerous complex compounds, many of its compounds with organic matter. As can be seen from the list of compounds in which titanium can participate, it is chemically very active. And at the same time, titanium is one of the few metals with exceptionally high corrosion resistance: it is practically eternal in the air atmosphere, in cold and boiling water, and is very resistant to corrosion. sea water, in solutions of many salts, inorganic and organic acids. In terms of its corrosion resistance in sea water, it surpasses all metals, with the exception of noble ones - gold, platinum, etc., most types of stainless steel, nickel, copper and other alloys. In water, in many aggressive environments, pure titanium is not subject to corrosion. Resists titanium and erosion corrosion resulting from a combination of chemical and mechanical effects on the metal. In this regard, it is not inferior to the best grades of stainless steels, copper-based alloys and other structural materials. Titanium also resists fatigue corrosion well, which often manifests itself in the form of violations of the integrity and strength of the metal (cracking, local corrosion centers, etc.). The behavior of titanium in many aggressive environments, such as nitrogen, hydrochloric, sulfuric, "aqua regia" and other acids and alkalis, is surprising and admirable for this metal.

Titanium is a very refractory metal. For a long time it was believed that it melts at 1800 ° C, but in the mid-50s. English scientists Diardorf and Hayes established the melting point for pure elemental titanium. It amounted to 1668 ± 3 ° C. In terms of its refractoriness, titanium is inferior only to such metals as tungsten, tantalum, niobium, rhenium, molybdenum, platinoids, zirconium, and among the main structural metals it is in first place. The most important feature of titanium as a metal is its unique physical and chemical properties: low density, high strength, hardness, etc. The main thing is that these properties do not change significantly at high temperatures.

Titanium is a light metal, its density at 0°C is only 4.517 g/cm8, and at 100°C it is 4.506 g/cm3. Titanium belongs to the group of metals with a specific gravity of less than 5 g/cm3. This includes all alkali metals(sodium, cadium, lithium, rubidium, cesium) with a specific gravity of 0.9–1.5 g/cm3, magnesium (1.7 g/cm3), aluminum (2.7 g/cm3), etc. Titanium more than 1.5 times heavier than aluminum, and in this, of course, it loses to it, but it is 1.5 times lighter than iron (7.8 g / cm3). However, taking specific gravity an intermediate position between aluminum and iron, titanium surpasses them many times in its mechanical properties.). Titanium has a significant hardness: it is 12 times harder than aluminum, 4 times harder than iron and copper. Another important characteristic of a metal is its yield strength. The higher it is, the better the parts made of this metal resist operational loads. The yield strength of titanium is almost 18 times higher than that of aluminum. The specific strength of titanium alloys can be increased by a factor of 1.5–2. Its high mechanical properties are well preserved at temperatures up to several hundred degrees. Pure titanium is suitable for all types of processing in hot and cold states: it can be forged like iron, drawn and even made into wire, rolled into sheets, tapes, and foils up to 0.01 mm thick.

Unlike most metals, titanium has significant electrical resistance: if the electrical conductivity of silver is taken as 100, then the electrical conductivity of copper is 94, aluminum is 60, iron and platinum is -15, and titanium is only 3.8. Titanium is a paramagnetic metal, it is not magnetized like iron in a magnetic field, but it is not pushed out of it like copper. Its magnetic susceptibility is very weak, this property can be used in construction. Titanium has a relatively low thermal conductivity, only 22.07 W / (mK), which is approximately 3 times lower than the thermal conductivity of iron, 7 times lower than magnesium, 17–20 times lower than aluminum and copper. Accordingly, the coefficient of linear thermal expansion of titanium is lower than that of other structural materials: at 20 C, it is 1.5 times lower than that of iron, 2 - for copper, and almost 3 - for aluminum. Thus, titanium is a poor conductor of electricity and heat.

Due to the high corrosion resistance in sea water, titanium and its alloys are used in shipbuilding for the manufacture of propellers, ship plating, submarines, torpedoes, etc. Shells do not stick to titanium and its alloys, which sharply increase the resistance of the vessel when it moves. Gradually, the areas of application of titanium are expanding. Titanium and its alloys are used in the chemical, petrochemical, pulp and paper and food industries, non-ferrous metallurgy, power engineering, electronics, nuclear technology, electroplating, in the manufacture of weapons, for the manufacture of armor plates, surgical instruments, surgical implants, desalination plants, racing car parts , sports equipment (golf clubs, climbing equipment), watch parts and even jewelry. Nitriding of titanium leads to the formation of a golden film on its surface, which is not inferior in beauty to real gold.

The discovery of TiO2 was made almost simultaneously and independently by the Englishman W. Gregor and the German chemist M. G. Klaproth. W. Gregor, studying the composition of magnetic ferruginous sand (Creed, Cornwall, England, 1791), isolated a new "earth" (oxide) of an unknown metal, which he called menaken. In 1795, the German chemist Klaproth discovered a new element in the mineral rutile and named it titanium. Two years later, Klaproth established that rutile and menaken earth are oxides of the same element, behind which the name "titanium" proposed by Klaproth remained. After 10 years, the discovery of titanium took place for the third time. The French scientist L. Vauquelin discovered titanium in anatase and proved that rutile and anatase are identical titanium oxides.

The first sample of metallic titanium was obtained in 1825 by J. Ya. Berzelius. Due to the high chemical activity of titanium and the complexity of its purification, the Dutch A. van Arkel and I. de Boer obtained a pure Ti sample in 1925 by thermal decomposition of titanium iodide TiI4 vapor.

Titanium is the 10th most abundant in nature. The content in the earth's crust is 0.57% by mass, in sea water 0.001 mg / l. 300 g/t in ultrabasic rocks, 9 kg/t in basic rocks, 2.3 kg/t in acid rocks, 4.5 kg/t in clays and shales. In the earth's crust, titanium is almost always tetravalent and is present only in oxygen compounds. It does not occur in free form. Titanium under conditions of weathering and precipitation has a geochemical affinity for Al2O3. It is concentrated in bauxites of the weathering crust and in marine clayey sediments. The transfer of titanium is carried out in the form of mechanical fragments of minerals and in the form of colloids. Up to 30% TiO2 by weight accumulates in some clays. Titanium minerals are resistant to weathering and form large concentrations in placers. More than 100 minerals containing titanium are known. The most important of them are: rutile TiO2, ilmenite FeTiO3, titanomagnetite FeTiO3 + Fe3O4, perovskite CaTiO3, titanite CaTiSiO5. There are primary titanium ores - ilmenite-titanomagnetite and placer - rutile-ilmenite-zircon.

Main ores: ilmenite (FeTiO3), rutile (TiO2), titanite (CaTiSiO5).

In 2002, 90% of the mined titanium was used for the production of titanium dioxide TiO2. World production of titanium dioxide was 4.5 million tons per year. The confirmed reserves of titanium dioxide (without Russia) are about 800 million tons. For 2006, according to the US Geological Survey, in terms of titanium dioxide and excluding Russia, the reserves of ilmenite ores amount to 603-673 million tons, and rutile - 49.7- 52.7 million tons. Thus, at the current rate of production, the world's proven reserves of titanium (excluding Russia) will be enough for more than 150 years.

Russia has the world's second largest reserves of titanium after China. The mineral resource base of titanium in Russia consists of 20 deposits (of which 11 are primary and 9 are alluvial), fairly evenly dispersed throughout the country. The largest of the explored deposits (Yaregskoye) is located 25 km from the city of Ukhta (Komi Republic). The reserves of the deposit are estimated at 2 billion tons of ore with an average titanium dioxide content of about 10%.

The world's largest producer of titanium - Russian company"VSMPO-AVISMA".

As a rule, the starting material for the production of titanium and its compounds is titanium dioxide with a relatively small amount of impurities. In particular, it can be a rutile concentrate obtained during the beneficiation of titanium ores. However, the reserves of rutile in the world are very limited, and the so-called synthetic rutile or titanium slag, obtained during the processing of ilmenite concentrates, is more often used. To obtain titanium slag, ilmenite concentrate is reduced in an electric arc furnace, while iron is separated into a metal phase (cast iron), and not reduced titanium oxides and impurities form a slag phase. Rich slag is processed by the chloride or sulfuric acid method.

In pure form and in the form of alloys

Titanium monument to Gagarin on Leninsky Prospekt in Moscow

The metal is used in: chemical industry (reactors, pipelines, pumps, pipeline fittings), military industry (bulletproof vests, armor and fire barriers in aviation, submarine hulls), industrial processes(desalination plants, pulp and paper processes), automotive industry, agricultural industry, food industry, piercing jewelry, medical industry (prostheses, osteoprostheses), dental and endodontic instruments, dental implants, sporting goods, jewelry (Alexander Khomov), mobile phones, light alloys, etc. Is the most important structural material in aircraft, rocket and shipbuilding.

Titanium casting is carried out in vacuum furnaces in graphite molds. Vacuum investment casting is also used. Due to technological difficulties, it is used in artistic casting to a limited extent. The first monumental cast titanium sculpture in the world is the monument to Yuri Gagarin on the square named after him in Moscow.

Titanium is an alloying addition in many alloy steels and most special alloys.

Nitinol (nickel-titanium) is a shape memory alloy used in medicine and technology.

Titanium aluminides are very resistant to oxidation and heat-resistant, which in turn determined their use in aviation and automotive industry as structural materials.

Titanium is one of the most common getter materials used in high vacuum pumps.

White titanium dioxide (TiO2) is used in paints (such as titanium white) as well as in the manufacture of paper and plastics. Food additive E171.

Organotitanium compounds (eg tetrabutoxytitanium) are used as a catalyst and hardener in the chemical and paint industries.

Inorganic titanium compounds are used in the chemical, electronic, glass fiber industries as additives or coatings.

Titanium carbide, titanium diboride, titanium carbonitride are important components of superhard materials for metal processing.

Titanium nitride is used to coat tools, church domes and in the manufacture of costume jewelry, because. has a color similar to gold.

Barium titanate BaTiO3, lead titanate PbTiO3 and a number of other titanates are ferroelectrics.

There are many titanium alloys with different metals. Alloying elements are divided into three groups, depending on their effect on the temperature of polymorphic transformation: beta stabilizers, alpha stabilizers and neutral hardeners. The former lower the transformation temperature, the latter increase it, and the latter do not affect it, but lead to solution hardening of the matrix. Examples of alpha stabilizers: aluminum, oxygen, carbon, nitrogen. Beta stabilizers: molybdenum, vanadium, iron, chromium, nickel. Neutral hardeners: zirconium, tin, silicon. Beta stabilizers, in turn, are divided into beta-isomorphic and beta-eutectoid-forming. The most common titanium alloy is the Ti-6Al-4V alloy (in the Russian classification - VT6).

60% - paint;

20% - plastic;

13% - paper;

7% - mechanical engineering.

$15-25 per kilo, depending on purity.

The purity and grade of rough titanium (titanium sponge) is usually determined by its hardness, which depends on the content of impurities. The most common brands are TG100 and TG110.

The price of ferrotitanium (minimum 70% titanium) as of 12/22/2010 is $6.82 per kilogram. On 01.01.2010 the price was at the level of $5.00 per kilogram.

In Russia, titanium prices at the beginning of 2012 were 1200-1500 rubles/kg.

Advantages:

low density (4500 kg / m3) helps to reduce the mass of the material used;

high mechanical strength. It is worth noting that at elevated temperatures(250-500 °C) titanium alloys are superior in strength to high-strength aluminum and magnesium alloys;

unusually high corrosion resistance, due to the ability of titanium to form thin (5-15 microns) continuous films of TiO2 oxide on the surface, firmly bonded to the metal mass;

the specific strength (ratio of strength and density) of the best titanium alloys reaches 30-35 or more, which is almost twice the specific strength of alloyed steels.

Disadvantages:

high production cost, titanium is much more expensive than iron, aluminum, copper, magnesium;

active interaction at high temperatures, especially in the liquid state, with all gases that make up the atmosphere, as a result of which titanium and its alloys can only be melted in a vacuum or in an environment inert gases;

difficulties involved in the production of titanium waste;

poor antifriction properties due to titanium sticking to many materials, titanium paired with titanium cannot work for friction;

high propensity of titanium and many of its alloys to hydrogen embrittlement and salt corrosion;

poor machinability similar to that of austenitic stainless steels;

high reactivity, a tendency to grain growth at high temperature and phase transformations during the welding cycle cause difficulties in welding titanium.

The main part of titanium is spent on the needs of aviation and rocket technology and marine shipbuilding. Titanium (ferrotitanium) is used as an alloying additive to high-quality steels and as a deoxidizer. Technical titanium is used for the manufacture of tanks, chemical reactors, pipelines, fittings, pumps, valves and other products operating in aggressive environments. Grids and other parts of electrovacuum devices operating at high temperatures are made from compact titanium.

In terms of use as a structural material, titanium is in 4th place, second only to Al, Fe and Mg. Titanium aluminides are very resistant to oxidation and heat-resistant, which in turn determined their use in aviation and automotive industry as structural materials. The biological safety of titanium makes it an excellent material for the food industry and reconstructive surgery.

Titanium and its alloys are widely used in engineering due to their high mechanical strength, which is maintained at high temperatures, corrosion resistance, heat resistance, specific strength, low density and other useful properties. The high cost of titanium and its alloys is in many cases offset by their greater performance, and in some cases they are the only material from which it is possible to manufacture equipment or structures capable of operating under given specific conditions.

Titanium alloys play an important role in aviation technology, where the aim is to obtain the lightest design combined with the required strength. Titanium is light compared to other metals, but at the same time it can work at high temperatures. Titanium alloys are used to make skin, fastening parts, a power set, chassis parts, and various units. Also, these materials are used in the construction of aircraft jet engines. This allows you to reduce their weight by 10-25%. Titanium alloys are used to produce compressor disks and blades, air intake and guide vane parts, and fasteners.

Titanium and its alloys are also used in rocket science. In view of short-term work engines and the rapid passage of dense layers of the atmosphere in rocket science, the problems of fatigue strength, static endurance, and partly creep are largely removed.

Technical titanium is not suitable for aviation applications due to its insufficiently high heat resistance, but due to its exceptionally high corrosion resistance, in some cases it is indispensable in the chemical industry and shipbuilding. So it is used in the manufacture of compressors and pumps for pumping such aggressive media as sulfuric and hydrochloric acid and their salts, pipelines, valves, autoclaves, various containers, filters, etc. Only titanium has corrosion resistance in such media as wet chlorine, water and acid solutions chlorine, therefore equipment for the chlorine industry is made from this metal. Titanium is used to make heat exchangers operating in corrosive environments, for example, in nitric acid(not smoky). In shipbuilding, titanium is used for the manufacture of propellers, plating of ships, submarines, torpedoes, etc. Shells do not stick to titanium and its alloys, which sharply increase the resistance of the vessel when it moves.

Titanium alloys are promising for use in many other applications, but their use in technology is constrained by the high cost and scarcity of titanium.

Titanium compounds are also widely used in various industries. Titanium carbide has a high hardness and is used in the manufacture of cutting tools and abrasive materials. White titanium dioxide (TiO2) is used in paints (such as titanium white) as well as in the manufacture of paper and plastics. Organotitanium compounds (eg tetrabutoxytitanium) are used as a catalyst and hardener in the chemical and paint industries. Inorganic titanium compounds are used in the chemical, electronic, fiberglass industry as an additive. Titanium diboride is an important component of superhard metalworking materials. Titanium nitride is used to coat tools.

With the existing high prices for titanium, it is mainly used for the production of military equipment, where the main role belongs not to cost, but to technical characteristics. However, there are known uses unique properties titanium for civil needs. As the price of titanium declines and its production grows, the use of this metal in military and civilian purposes will expand more and more.

Aviation. The low specific gravity and high strength (especially at elevated temperatures) of titanium and its alloys make them highly valuable aviation materials. In the field of aircraft construction and the production of aircraft engines, titanium is increasingly replacing aluminum and stainless steel. As the temperature rises, aluminum quickly loses its strength. On the other hand, titanium has a clear advantage in terms of strength at temperatures up to 430 ° C, and elevated temperatures of this order occur at high speeds due to aerodynamic heating. The advantage of replacing steel with titanium in aviation is to reduce weight without sacrificing strength. The overall reduction in weight with increased performance at elevated temperatures allows for increased payload, range and maneuverability of aircraft. This explains the efforts aimed at expanding the use of titanium in aircraft construction in the manufacture of engines, the construction of fuselages, the manufacture of skins and even fasteners.

In the construction of jet engines, titanium is mainly used for the manufacture of compressor blades, turbine disks and many other stamped parts. Here, titanium is replacing stainless and heat-treated alloy steels. A saving of one kilogram in engine weight saves up to 10 kg in the total weight of the aircraft due to the lightening of the fuselage. In the future, it is planned to use sheet titanium for the manufacture of casings for engine combustion chambers.

In aircraft construction, titanium is widely used for fuselage parts operating at elevated temperatures. Sheet titanium is used for the manufacture of all kinds of casings, protective sheaths of cables and guides for projectiles. Various stiffening elements, fuselage frames, ribs, etc. are made from alloyed titanium sheets.

Shrouds, flaps, cable sheaths and projectile guides are made from unalloyed titanium. Alloyed titanium is used for the manufacture of the fuselage frame, frames, pipelines and fire barriers.

Titanium is increasingly used in the construction of the F-86 and F-100 aircraft. In the future, titanium will be used to make landing gear doors, hydraulic piping, exhaust pipes and nozzles, spars, flaps, folding struts, etc.

Titanium can be used to make armor plates, propeller blades, and shell boxes.

At present, titanium is used in the construction of military aircraft Douglas X-3 for skin, Republic F-84F, Curtiss-Wright J-65 and Boeing B-52.

Titanium is also used in the construction of civil aircraft DC-7. The Douglas company, by replacing aluminum alloys and stainless steel with titanium in the manufacture of the engine nacelle and fire barriers, has already achieved savings in the weight of the aircraft structure of about 90 kg. Currently, the weight of titanium parts in this aircraft is 2%, and this figure is expected to be increased to 20% of the total weight of the aircraft.

The use of titanium makes it possible to reduce the weight of helicopters. Sheet titanium is used for floors and doors. A significant reduction in the weight of the helicopter (about 30 kg) was achieved by replacing alloyed steel with titanium for sheathing the blades of its rotors.

Navy. The corrosion resistance of titanium and its alloys makes them a highly valuable material at sea. The US Department of the Navy is extensively investigating the corrosion resistance of titanium against exposure to flue gases, steam, oil, and sea water. The high specific strength of titanium is of almost the same importance in naval affairs.

The low specific gravity of the metal, combined with corrosion resistance, increases the maneuverability and range of the ships, and also reduces the cost of maintaining the material part and its repair.

Applications of titanium in the navy include exhaust mufflers for submarine diesel engines, instrument discs, thin-walled tubes for condensers and heat exchangers. According to experts, titanium, like no other metal, is able to increase the life of exhaust mufflers on submarines. For gauge discs exposed to salt water, gasoline or oil, titanium will provide better durability. The possibility of using titanium for the manufacture of heat exchanger tubes is being investigated, which should be corrosion resistant in sea water washing the tubes from the outside, and at the same time withstand the effects of exhaust condensate flowing inside them. The possibility of manufacturing antennas and components of radar installations from titanium, which are required to be resistant to the effects of flue gases and sea water, is being considered. Titanium can also be used for the production of parts such as valves, propellers, turbine parts, etc.

Artillery. Apparently, the largest potential consumer of titanium may be artillery, where intensive research is currently underway on various prototypes. However, in this area, the production of only individual parts and parts made of titanium is standardized. Very limited use titanium in artillery with a large scope of research is explained by its high cost.

Various details have been explored artillery equipment in terms of the possibility of replacing conventional materials with titanium, subject to a reduction in titanium prices. The main attention was paid to parts for which weight reduction is essential (parts carried by hand and transported by air).

Mortar baseplate made from titanium instead of steel. By such a replacement and after some alteration, instead of a steel plate from two halves with a total weight of 22 kg, it was possible to create one part weighing 11 kg. Thanks to this replacement, it is possible to reduce the number of service personnel from three to two. The possibility of using titanium for the manufacture of gun flame arresters is being considered.

Titanium-made gun mounts, carriage crosses and recoil cylinders are being tested. Wide application titanium can be obtained in the production of guided projectiles and missiles.

The first studies of titanium and its alloys showed the possibility of manufacturing armor plates from them. Replacement of steel armor (thickness 12.7 mm) titanium armor the same projectile resistance (thickness 16 mm) makes it possible, according to these studies, to save up to 25% in weight.

High-quality titanium alloys give hope for the possibility of replacing steel plates with titanium plates of equal thickness, which saves up to 44% in weight. Industrial Application titanium will provide greater maneuverability, increase the range of transportation and durability of the gun. The current level of development of air transport makes obvious the advantages of light armored cars and other vehicles made of titanium. The artillery department intends to equip infantry with helmets, bayonets, grenade launchers and hand-held flamethrowers made of titanium in the future. Titanium alloy was first used in artillery for the manufacture of the piston of some automatic guns.

Transport. Many of the benefits of using titanium in the production of armored materiel apply to vehicles as well.

The replacement of structural materials currently consumed by transport engineering enterprises with titanium should lead to a reduction in fuel consumption, an increase in payload capacity, an increase in the fatigue limit of parts of crank mechanisms, etc. railways it is essential to reduce dead weight. A significant reduction in the total weight of the rolling stock due to the use of titanium will save in traction, reduce the dimensions of the necks and axle boxes.

Weight is also important for trailers. Vehicle. Here, the replacement of steel with titanium in the production of axles and wheels would also increase the payload capacity.

All these opportunities could be realized by reducing the price of titanium from 15 to 2-3 dollars per pound of titanium semi-finished products.

Chemical industry. In the production of equipment for the chemical industry, the corrosion resistance of the metal is of the utmost importance. It is also essential to reduce the weight and increase the strength of the equipment. Logically, it should be assumed that titanium could provide a number of benefits in the production of equipment for transporting acids, alkalis and inorganic salts from it. Additional possibilities for the use of titanium are opening up in the production of such equipment as tanks, columns, filters and all kinds of high-pressure cylinders.

The use of titanium piping can improve the efficiency of heating coils in laboratory autoclaves and heat exchangers. The applicability of titanium for the production of cylinders in which gases and liquids are stored under pressure for a long time is evidenced by the use in microanalysis of combustion products instead of a heavier glass tube (shown in the upper part of the image). Due to its small wall thickness and low specific gravity, this tube can be weighed on smaller, more sensitive analytical balances. Here, the combination of lightness and corrosion resistance improves the accuracy of chemical analysis.

Other applications. The use of titanium is expedient in the food, oil and electrical industries, as well as for the manufacture of surgical instruments and in surgery itself.

Tables for food preparation, steaming tables made of titanium are superior in quality to steel products.

In the oil and gas drilling industry, the fight against corrosion is of great importance, so the use of titanium will make it possible to replace corroding equipment rods less frequently. In catalytic production and for the manufacture of oil pipelines, it is desirable to use titanium, which retains mechanical properties at high temperatures and has good corrosion resistance.

In the electrical industry, titanium can be used to armor cables due to its good specific strength, high electrical resistance and non-magnetic properties.

In various industries, fasteners of one form or another made of titanium are beginning to be used. Further expansion of the use of titanium is possible for the manufacture of surgical instruments, mainly due to its corrosion resistance. Titanium instruments are superior in this respect to conventional surgical instruments when repeatedly boiled or autoclaved.

In the field of surgery, titanium proved to be better than vitallium and stainless steels. The presence of titanium in the body is quite acceptable. The plate and screws made of titanium for fastening the bones were in the body of the animal for several months, and the bone grew into the threads of the screws and into the hole in the plate.

The advantage of titanium also lies in the fact that muscle tissue is formed on the plate.

Approximately half of the titanium products produced in the world are usually sent to the civil aircraft industry, but its decline after the well-known tragic events is forcing many industry participants to look for new applications for titanium. This material represents the first part of a selection of publications in the foreign metallurgical press devoted to the prospects of titanium in modern conditions. According to one of the leading American manufacturers of titanium RT1, out of the total volume of titanium production on a global scale at the level of 50-60 thousand tons per year, the aerospace segment accounts for up to 40 consumption, industrial applications and applications account for 34, and the military area 16 , and about 10 accounted for the use of titanium in consumer products. Industrial applications of titanium include chemical processes, energy, oil and gas industry, desalination plants. Military non-aeronautical applications include primarily use in artillery and combat vehicles. Sectors with significant use of titanium are the automotive industry, architecture and construction, sporting goods, and jewelry. Almost all titanium in ingots is produced in the USA, Japan and the CIS - Europe accounts for only 3.6 of the global volume. Regional end-use markets for titanium vary greatly - most a prime example Japan is unique, where the civil aerospace sector accounts for only 2-3 while using 30 of the total titanium consumption in equipment and structural elements of chemical plants. Approximately 20 of the total demand in Japan comes from nuclear power and in solid fuel power plants, the rest is in architecture, medicine and sports. The opposite picture is observed in the US and Europe, where exclusively great importance has consumption in the aerospace sector - 60-75 and 50-60 for each region, respectively. In the US, traditionally strong end markets are chemicals, medical equipment, industrial equipment, while in Europe the largest share is in the oil and gas industry and the construction industry. The heavy reliance on the aerospace industry has been a long-standing concern for the titanium industry, which is trying to expand titanium applications, especially in the current downturn in global civil aviation. According to the US Geological Survey, in the first quarter of 2003 there was a significant decline in imports of titanium sponge - only 1319 tons, which is 62 less than 3431 tons in the same period of 2002. The aerospace sector will always be one of the leading markets for titanium, but we in the titanium industry must rise to the challenge and do everything we can to make sure our industry does not development and recession cycles in the aerospace sector. Some of the titanium industry's leading manufacturers see growing opportunities in existing markets, one of which is the subsea equipment and materials market. According to Martin Proko, Sales and Distribution Manager for RT1, titanium has been used in power generation and underwater applications for a long time, since the early 1980s, but only in the last five years have these areas become steadily developing with a corresponding growth in the market niche. In the subsea sector, the growth is primarily driven by drilling operations at greater depths, where titanium is the most suitable material. Its, so to speak, underwater life cycle is fifty years, which corresponds to the usual duration of underwater projects. We have already listed the areas in which an increase in the use of titanium is likely. Howmet Ti-Cast sales manager Bob Funnell notes that the current state of the market can be seen as growth opportunities in new areas such as rotating parts for truck turbochargers, rockets and pumps.

One of our ongoing projects is the development of BAE Butitzer XM777 light artillery systems with a caliber of 155 mm. Newmet will supply 17 of the 28 structural titanium assemblies for each gun mount, with deliveries to the US Marine Corps due in August 2004. With a total gun weight of 9,800 pounds of approximately 4.44 tons, titanium accounts for about 2,600 pounds of approximately 1.18 tons of titanium in its design - a 6A14U alloy with a large number of castings is used, says Frank Hrster, head of fire support systems BAE Sy81et8. This XM777 system is to replace the current M198 Newitzer system, which weighs about 17,000 pounds and approximately 7.71 tons. Mass production is planned for the period from 2006 to 2010 - deliveries to the USA, Great Britain and Italy are initially scheduled, but the program may be expanded for deliveries to NATO member countries. John Barber of Timet points out that examples military equipment, in the design of which significant volumes of titanium are used, are the Abramé tank and fighting machine Bradley. For the past two years, a joint program between NATO, the US and the UK has been underway to intensify the use of titanium in weapons and defense systems. As has been noted more than once, titanium is very suitable for use in the automotive industry, however, the share of this direction is rather modest - about 1 of the total volume of titanium consumed, or 500 tons per year, according to the Italian company Poggipolini, a manufacturer of titanium components and parts for Formula- 1 and racing motorcycles. Daniele Stoppolini, head of research and development at this company, believes that the current demand for titanium in this market segment is at the level of 500 tons, with the massive use of this material in the construction of valves, springs, exhaust systems, transmission shafts, bolts, could potentially rise to the level of almost not 16,000 tons per year He added that his company is just beginning to develop automated production of titanium bolts in order to reduce production costs. In his opinion, the limiting factors, due to which the use of titanium does not expand significantly in the automotive industry, are the unpredictability of demand and the uncertainty with the supply of raw materials. At the same time, a large potential niche for titanium remains in the automotive industry, combining optimal weight and strength characteristics for coil springs and exhaust gas systems. Unfortunately, in the American market, the wide use of titanium in these systems is marked only by a fairly exclusive semi-sport model Chevrolet Corvette Z06, which can in no way claim to be a mass car. However, due to the ongoing challenges of fuel economy and corrosion resistance, the prospects for titanium in this area remain. For approval in the markets of non-aerospace and non-military applications, the UNITI joint venture was recently created in its name, the word unity is played up - unity and Ti - the designation of titanium in the periodic table as part of the world's leading titanium producers - American Allegheny Technologies and Russian VSMPO-Avisma. These markets have been deliberately excluded, said Carl Moulton, president of the new company, as we intend to make the new company a leading supplier to industries using titanium parts and assemblies, primarily petrochemicals and power generation. In addition, we intend to actively market in the fields of desalination devices, vehicles, consumer products and electronics. I believe that our production facilities complement each other well - VSMPO has outstanding capabilities for the production of end products, Allegheny has excellent traditions in the production of cold and hot titanium rolled products. UNITI's share of the global titanium products market is expected to be 45 million pounds, approximately 20,411 tons. The market of medical equipment can be considered a steadily developing market - according to the British Titanium International Group, the annual content of titanium worldwide in various implants and prostheses is about 1000 tons, and this figure will increase, as the possibilities of surgery to replace human joints after accidents or injuries. In addition to the obvious advantages of flexibility, strength, lightness, titanium is highly compatible with the body in a biological sense due to the absence of corrosion to tissues and fluids in the human body. In dentistry, the use of prostheses and implants is also skyrocketing - three times in the last ten years, according to the American Dental Association, largely due to the characteristics of titanium. Although the use of titanium in architecture dates back more than 25 years, its widespread use in this area began only in last years. The expansion of Abu Dhabi Airport in the UAE, scheduled for completion in 2006, will use up to 1.5 million pounds of approximately 680 tons of titanium. Quite a lot of various architectural and construction projects using titanium are planned to be implemented not only in the developed countries of the USA, Canada, Great Britain, Germany, Switzerland, Belgium, Singapore, but also in Egypt and Peru.

The consumer goods market segment is currently the fastest growing segment of the titanium market. While 10 years ago this segment was only 1-2 of the titanium market, today it has grown to 8-10 of the market. Overall, titanium consumption in the consumer goods industry grew at about twice the rate of the entire titanium market. The use of titanium in sports is the longest running and holds the largest share of the use of titanium in consumer products. The reason for the popularity of titanium in sports equipment is simple - it allows you to get a ratio of weight and strength superior to any other metal. The use of titanium in bicycles began about 25-30 years ago and was the first use of titanium in sports equipment. Ti3Al-2.5V ASTM Grade 9 alloy tubes are mainly used. Other parts made from titanium alloys include brakes, sprockets and seat springs. The use of titanium in the manufacture of golf clubs first began in the late 80s and early 90s by club manufacturers in Japan. Prior to 1994-1995, this application of titanium was virtually unknown in the US and Europe. That changed when Callaway introduced its Ruger Titanium titanium stick, called the Great Big Bertha. Due to the obvious benefits and well-thought-out marketing from Callaway, titanium clubs became an instant hit. Within a short period of time, titanium clubs have gone from the exclusive and expensive equipment of a small group of golfers to being widely used by most golfers while still being more expensive than steel clubs. I would like to cite the main, in my opinion, trends in the development of the golf market; it has gone from high-tech to mass production in a short period of 4-5 years, following the path of other industries with high labor costs such as the production of clothing, toys and consumer electronics, the production of golf clubs has gone into countries with the cheapest labor first to Taiwan, then to China, and now factories are being built in countries with even cheaper labor, such as Vietnam and Thailand, titanium is definitely used for drivers, where its superior qualities give a clear advantage and justify a higher price . However, titanium has not yet found very widespread use on subsequent clubs, as the significant increase in costs is not supported by a corresponding improvement in the game. Currently, drivers are mainly produced with a forged striking surface, a forged or cast top and a cast bottom. Recently, the Professional Golf Association ROA allowed an increase the upper limit of the so-called return factor, in connection with which all club manufacturers will try to increase the spring properties of the striking surface. To do this, it is necessary to reduce the thickness of the impact surface and use stronger alloys for it, such as SP700, 15-3-3-3 and VT-23. Now let's focus on the use of titanium and its alloys on other sports equipment. Race bike tubes and other parts are made from ASTM Grade 9 Ti3Al-2.5V alloy. A surprisingly significant amount of titanium sheet is used in the manufacture of scuba diving knives. Most manufacturers use Ti6Al-4V alloy, but this alloy does not provide blade edge durability like other stronger alloys. Some manufacturers are switching to using BT23 alloy.

The retail price of titanium scuba knives is approximately $70-80. Cast titanium horseshoes provide a significant reduction in weight compared to steel, while providing the necessary strength. Unfortunately, this use of titanium did not materialize because the titanium horseshoes sparkled and frightened the horses. Few will agree to use titanium horseshoes after the first unsuccessful experiments. Titanium Beach, based in Newport Beach, California Newport Beach, California, has developed Ti6Al-4V alloy skate blades. Unfortunately, here again the problem is the durability of the edge of the blades. I think that this product has a chance to live if manufacturers use stronger alloys such as 15-3-3-3 or BT-23. Titanium is very widely used in mountaineering and hiking, for almost all items that climbers and hikers carry in their backpacks bottles, cups $20-$30 retail, cooking sets about $50 retail, dinnerware mostly made from commercially pure titanium Grade 1 and 2. Other examples of climbing and hiking equipment are compact stoves, tent racks and mounts, ice axes and ice screws. Arms manufacturers have recently begun producing titanium pistols for both sport shooting and law enforcement applications.

Consumer electronics is a fairly new and rapidly growing market for titanium. In many cases, the use of titanium in consumer electronics is not only due to its excellent properties, but also due to the attractive appearance of the products. Commercially pure Grade 1 titanium is used to make cases for laptop computers, mobile phones, plasma flat screen TVs and other electronic equipment. The use of titanium in speaker construction provides better acoustic properties due to titanium being lighter than steel resulting in increased acoustic sensitivity. Titanium watches, first introduced to the market by Japanese manufacturers, are now one of the most affordable and recognized consumer titanium products. World consumption of titanium in the production of traditional and so-called wearable jewelry is measured in several tens of tons. Increasingly, you can find titanium wedding rings, and of course, people wearing jewelry on the body are simply obliged to use titanium. Titanium is widely used in the manufacture of marine fasteners and fittings, where the combination of high corrosion resistance and strength is very important. Los Angeles-based Atlas Ti manufactures a wide range of these products in VTZ-1 alloy. The use of titanium in the production of tools first began in the Soviet Union in the early 80s, when, on the instructions of the government, light and convenient tools were made to facilitate the work of workers. The Soviet giant of titanium production, the Verkhne-Saldinskoye Metal Processing Production Association, at that time produced titanium shovels, nail pullers, mounts, hatchets and keys.

Later, Japanese and American tool manufacturers began to use titanium in their products. Not so long ago, VSMPO signed a contract with Boeing for the supply of titanium plates. This contract undoubtedly had a very beneficial effect on the development of titanium production in Russia. Titanium has been widely used in medicine for many years. The advantages are strength, corrosion resistance, and most importantly, some people are allergic to nickel, a necessary component of stainless steels, while no one is allergic to titanium. The alloys used are commercially pure titanium and Ti6-4Eli. Titanium is used in the manufacture of surgical instruments, internal and external prostheses, including critical ones such as a heart valve. Crutches and wheelchairs are made from titanium. The use of titanium in art dates back to 1967, when the first titanium monument was erected in Moscow.

At the moment, a significant number of titanium monuments and buildings have been erected on almost all continents, including such famous ones as the Guggenheim Museum, built by architect Frank Gehry in Bilbao. The material is very popular with people of art for its color, appearance, strength and corrosion resistance. For these reasons, titanium is used in souvenirs and costume jewelry haberdashery, where it successfully competes with such precious metals as silver and even gold. . According to Martin Proko of RTi, the average price of titanium sponge in the US is 3.80 per pound, in Russia it is 3.20 per pound. In addition, the price of metal is highly dependent on the cyclicality of the commercial aerospace industry. The development of many projects could accelerate dramatically if ways can be found to reduce the costs of titanium production and processing, scrap processing and smelting technologies, said Markus Holz, managing director of the German Deutshe Titan. British Titanium agrees that titanium product expansion is being held back by high production costs and many improvements need to be made before titanium can be mass produced. modern technologies.

One of the steps in this direction is the development of the so-called FFC process, which is a new electrolytic process for the production of metallic titanium and alloys, the cost of which is significantly lower. According to Daniele Stoppolini, the overall strategy in the titanium industry requires the development of the most suitable alloys, production technology for each new market and application of titanium.

Sources

Wikipedia - The Free Encyclopedia, WikiPedia

metotech.ru - Metotechnics

housetop.com - House Top

atomsteel.com – Atom technology

domremstroy.ru - DomRemStroy

- element 4 of group 4 of the period. Transition metal, exhibits both basic and acidic properties, is quite widespread in nature - 10th place. The most interesting for the national economy is the combination of high metal hardness and lightness, which makes it an indispensable element for the aircraft industry. This article will tell you about the marking, alloying and other properties of titanium metal, give a general description and interesting facts about it.

In appearance, the metal is most reminiscent of steel, but its mechanical qualities are higher. At the same time, titanium is distinguished by its low weight - molecular weight 22. The physical properties of the element have been studied quite well, but they strongly depend on the purity of the metal, which leads to significant deviations.

In addition, its specific chemical properties matter. Titanium is resistant to alkalis, nitric acid, and at the same time violently interacts with dry halogens, and at higher temperatures with oxygen and nitrogen. Even worse, it begins to absorb hydrogen even at room temperature, if there is an active surface. And in the melt it absorbs oxygen and hydrogen so intensively that the melting has to be carried out in a vacuum.

Another important feature that determines the physical characteristics is the existence of 2 phases of the state.

Low temperature- α-Ti has a hexagonal close-packed lattice, the density of the substance is 4.55 g / cu. cm (at 20 C).
high temperature- β-Ti is characterized by a body-centered cubic lattice, the phase density, respectively, is less - 4.32 g / cu. see (at 900C).

Phase transition temperature - 883 C.

Under normal conditions, the metal is covered with a protective oxide film. In its absence, titanium is great danger. So, titanium dust can explode, the temperature of such a flash is 400C. Titanium chips are a fire hazardous material and are stored in a special environment.

The video below tells about the structure and properties of titanium:

Properties and characteristics of titanium

Titanium is by far the strongest among all existing technical materials, therefore, despite the complexity of obtaining and high security requirements for , it is used quite widely. The physical characteristics of the element are rather unusual, but very much depend on the purity. Thus, pure titanium and alloys are actively used in the rocket and aircraft industry, while technical titanium is unsuitable, because it loses strength at high temperatures due to impurities.

metal density

The density of a substance varies with temperature and phase.

At temperatures from 0 to the melting point, it decreases from 4.51 to 4.26 g / cu. cm, and during the phase transition you increase it by 0.15%, and then decrease again.
The density of the liquid metal is 4.12 g/cu. cm, and then decreases with increasing temperature.

Melting and boiling points

The phase transition separates all the properties of the metal into qualities that the α- and β-phases can exhibit. So, the density up to 883 C refers to the qualities of the α-phase, and the melting and boiling points - to the parameters of the β-phase.

The melting point of titanium (in degrees) is 1668+/-5 C;
The boiling point reaches 3227 C.

The combustion of titanium is discussed in this video:

Mechanical Features

Titanium is about 2 times stronger than iron and 6 times stronger than aluminum, which makes it such a valuable structural material. The exponents refer to the properties of the α-phase.

The tensile strength of the substance is 300–450 MPa. The indicator can be increased to 2000 MPa by adding some elements, as well as resorting to special processing - hardening and aging.

Interestingly, titanium retains high specific strength even at the lowest temperatures. Moreover, as the temperature decreases, the bending strength increases: at +20 C, the indicator is 700 MPa, and at -196 - 1100 MPa.

The elasticity of the metal is relatively low, which is a significant drawback of the substance. Modulus of elasticity at normal conditions 110.25 GPa. In addition, titanium is characterized by anisotropy: elasticity in different directions reaches different values.
The hardness of the substance on the HB scale is 103. Moreover, this indicator is averaged. Depending on the purity of the metal and the nature of the impurities, the hardness may be higher.
The conditional yield strength is 250–380 MPa. The higher this indicator, the better the products of the substance withstand loads and the more they resist wear. The index of titanium exceeds that of aluminum by 18 times.

Compared to other metals having the same lattice, the metal has a very decent ductility and malleability.

Heat capacity

The metal is characterized by low thermal conductivity, therefore, in the relevant areas - the manufacture of thermoelectrodes, for example, is not used.

Its thermal conductivity is 16.76 l, W / (m × deg). This is 4 times less than iron and 12 times less than iron.
But the coefficient of thermal expansion of titanium is negligible at normal temperature and increases with increasing temperature.
The heat capacity of the metal is 0.523 kJ/(kg K).

Electrical characteristics

As is often the case, low thermal conductivity leads to low electrical conductivity.

The electrical resistivity of the metal is very high - 42.1·10 -6 ohm·cm under normal conditions. If we consider the conductivity of silver to be 100%, then the conductivity of titanium will be 3.8%.
Titanium is a paramagnet, that is, it cannot be magnetized in the field, like iron, but also pushed out of the field, as it will not. This property decreases linearly with decreasing temperature, but, after passing the minimum, increases somewhat. Specific magnetic susceptibility is 3.2 10 -6 G -1 . It should be noted that the susceptibility, as well as elasticity, forms anisotropy and changes depending on the direction.

At a temperature of 3.8 K, titanium becomes a superconductor.

Corrosion resistance

Under normal conditions, titanium has very high anti-corrosion properties. In air, it is covered with a layer of titanium oxide with a thickness of 5–15 microns, which provides excellent chemical inertness. The metal does not corrode in air, sea air, sea water, wet chlorine, chlorine water and numerous other technological solutions and reagents, which makes the material indispensable in the chemical, paper, oil industries.

With an increase in temperature or a strong grinding of the metal, the picture changes dramatically. The metal reacts with almost all the gases that make up the atmosphere, and in the liquid state it also absorbs them.

Security

Titanium is one of the most biologically inert metals. In medicine, it is used for the manufacture of prostheses, as it is resistant to corrosion, lightweight and durable.

Titanium dioxide is not so safe, although it is used much more often - in the cosmetics and food industries, for example. According to some reports - UCLA, research by professor of pathology Robert Shistle, titanium dioxide nanoparticles affect the genetic apparatus and can contribute to the development of cancer. Moreover, the substance does not penetrate the skin, so the use of sunscreens, which contain dioxide, does not pose a danger, but a substance that enters the body - with food dyes, biological supplements, can be dangerous.

Titanium is a uniquely strong, hard and light metal with very interesting chemical and physical properties. This combination is so valuable that even the difficulties with smelting and refining titanium do not stop manufacturers.

This video will tell you how to distinguish titanium from steel:

Section 1. History and occurrence of titanium in nature.

Titanium — This an element of a side subgroup of the fourth group, the fourth period of the periodic system of chemical elements of D. I. Dmitry Ivanovich Mendeleev, with atomic number 22. A simple substance titanium(CAS number: 7440-32-6) - light silvery white. It exists in two crystalline modifications: α-Ti with a hexagonal close-packed lattice, β-Ti with a cubic body-centered packing, the temperature of the polymorphic transformation α↔β is 883 °C. Melting point 1660±20 °C.

History and presence in nature of titanium

Titanium was named after the ancient Greek characters Titans. The German chemist Martin Klaproth named it this way for his personal reasons, unlike the French, who tried to give names in accordance with the chemical characteristics of the element, but since the properties of the element were unknown at that time, such a name was chosen.

Titanium is the 10th element in terms of number of it on our planet. The amount of titanium in the earth's crust is 0.57% by weight and 0.001 milligrams per 1 liter of sea water. Titanium deposits are located on the territory of: South African Republic, Ukraine, Russian Federation, Kazakhstan, Japan, Australia, India, Ceylon, Brazil and South Korea.

According to the physical properties, titanium is light silvery metal, in addition, it is characterized by high viscosity during machining and is prone to sticking to the cutting tool, so special lubricants or spraying are used to eliminate this effect. At room temperature, it is covered with a translucent film of TiO2 oxide, due to which it is resistant to corrosion in most aggressive environments, except for alkalis. Titanium dust has the ability to explode, with a flash point of 400 °C. Titanium shavings are flammable.

The discoverer of titanium is considered to be 28-year-old English monk William Gregor. In 1790, while conducting mineralogical surveys in his parish, he drew attention to the prevalence and unusual properties of black sand in the valley of Menaken in the south-west of Britain and began to explore it. AT sand the priest discovered grains of a black shiny mineral, attracted by an ordinary magnet. Obtained in 1925 by Van Arkel and de Boer by the iodide method, the purest titanium turned out to be ductile and technological metal with many valuable properties that attracted the attention of a wide range of designers and engineers. In 1940, Croll proposed a magnesium-thermal method for extracting titanium from ores, which is still the main one at the present time. In 1947, the first 45 kg of commercially pure titanium were produced.

In the Periodic Table of the Elements Mendeleev Dmitry Ivanovich titanium has serial number 22. The atomic mass of natural titanium, calculated from the results of studies of its isotopes, is 47.926. So, the nucleus of a neutral titanium atom contains 22 protons. The number of neutrons, that is, neutral uncharged particles, is different: more often 26, but can vary from 24 to 28. Therefore, the number of titanium isotopes is different. In total, 13 isotopes of element No. 22 are now known. Natural titanium consists of a mixture of five stable isotopes, titanium-48 is the most widely represented, its share in natural ores is 73.99%. Titanium and other elements of the IVB subgroup are very similar in properties to the elements of the IIIB subgroup (scandium group), although they differ from the latter in their ability to exhibit a large valency. The similarity of titanium with scandium, yttrium, as well as with elements of the VB subgroup - vanadium and niobium, is also expressed in the fact that titanium is often found in natural minerals together with these elements. With monovalent halogens (fluorine, bromine, chlorine and iodine), it can form di-tri- and tetra compounds, with sulfur and elements of its group (selenium, tellurium) - mono- and disulfides, with oxygen - oxides, dioxides and trioxides.

Titanium also forms compounds with hydrogen (hydrides), nitrogen (nitrides), carbon (carbides), phosphorus (phosphides), arsenic (arsides), as well as compounds with many metals - intermetallic compounds. Titanium forms not only simple, but also numerous complex compounds; many of its compounds with organic substances are known. As can be seen from the list of compounds in which titanium can participate, it is chemically very active. And at the same time, titanium is one of the few metals with exceptionally high corrosion resistance: it is practically eternal in the air, in cold and boiling water, it is very resistant in sea water, in solutions of many salts, inorganic and organic acids. In terms of its corrosion resistance in sea water, it surpasses all metals, with the exception of noble ones - gold, platinum, etc., most types of stainless steel, nickel, copper and other alloys. In water, in many aggressive environments, pure titanium is not subject to corrosion. Resists titanium and erosion corrosion, which occurs as a result of a combination of chemical and mechanical effects on. In this regard, it is not inferior to the best grades of stainless steels, cuprum-based alloys and other structural materials. Titanium also resists fatigue corrosion well, which often manifests itself in the form of violations of the integrity and strength of the metal (cracking, local corrosion centers, etc.). The behavior of titanium in many aggressive environments, such as nitrogen, hydrochloric, sulfuric, "aqua regia" and other acids and alkalis, is surprising and admirable for this metal.

Titanium is a light metal, its density at 0°C is only 4.517 g/cm8, and at 100°C it is 4.506 g/cm3. Titanium belongs to the group of metals with a specific gravity of less than 5 g/cm3. This includes all alkali metals (sodium, cadium, lithium, rubidium, cesium) with a specific gravity of 0.9-1.5 g / cm3, magnesium (1.7 g / cm3), (2.7 g / cm3), etc. .Titanium is more than 1.5 times heavier aluminum, and in this, of course, he loses to him, but on the other hand, it is 1.5 times lighter than iron (7.8 g / cm3). However, occupying an intermediate position in terms of specific density between aluminum and iron, titanium surpasses them many times over in its mechanical properties.). Titanium has a significant hardness: it is 12 times harder than aluminum, 4 times gland and cuprum. Another important characteristic of a metal is its yield strength. The higher it is, the better the parts made of this metal resist operational loads. The yield strength of titanium is almost 18 times higher than that of aluminum. The specific strength of titanium alloys can be increased by 1.5-2 times. Its high mechanical properties are well preserved at temperatures up to several hundred degrees. Pure titanium is suitable for all types of hot and cold work: it can be forged as iron, stretch and even make a wire out of it, roll it into sheets, tapes, into foil up to 0.01 mm thick.

Unlike most metals, titanium has significant electrical resistance: if the electrical conductivity of silver is taken as 100, then the electrical conductivity cuprum equal to 94, aluminum - 60, iron and platinum-15, while titanium is only 3.8. Titanium is a paramagnetic metal, it is not magnetized, like in a magnetic field, but it is not pushed out of it, like. Its magnetic susceptibility is very weak, this property can be used in construction. Titanium has a relatively low thermal conductivity, only 22.07 W / (mK), which is approximately 3 times lower than the thermal conductivity of iron, 7 times of magnesium, 17-20 times of aluminum and cuprum. Accordingly, the coefficient of linear thermal expansion of titanium is lower than that of other structural materials: at 20 C, it is 1.5 times lower than that of iron, 2 - for cuprum, and almost 3 - for aluminum. Thus, titanium is a poor conductor of electricity and heat.

The discovery of TiO2 was made almost simultaneously and independently by the Englishman W. Gregor and the German chemist M. G. Klaproth. W. Gregor, investigating the composition of the magnetic glandular sand(Creed, Cornwall, England, 1791), isolated a new "earth" (oxide) of an unknown metal, which he called menaken. In 1795, the German chemist Klaproth discovered in mineral rutile a new element and called it titanium. Two years later, Klaproth established that rutile and menakenic oxides are oxides of the same element, behind which the name “titanium” proposed by Klaproth remained. After 10 years, the discovery of titanium took place for the third time. The French scientist L. Vauquelin discovered titanium in anatase and proved that rutile and anatase are identical titanium oxides.

The discovery of TiO2 was made almost simultaneously and independently by the Englishman W. Gregor and the German chemist M. G. Klaproth. W. Gregor, studying the composition of magnetic ferruginous sand (Creed, Cornwall, England, 1791), isolated a new "earth" (oxide) of an unknown metal, which he called menaken. In 1795, the German chemist Klaproth discovered in mineral rutile a new element and called it titanium. Two years later, Klaproth established that rutile and menaken earth were oxides of the same element, behind which the name “titanium” proposed by Klaproth remained. After 10 years, the discovery of titanium took place for the third time. The French scientist L. Vauquelin discovered titanium in anatase and proved that rutile and anatase are identical titanium oxides.

Titanium is the 10th most abundant in nature. The content in the earth's crust is 0.57% by mass, in sea water 0.001 mg / l. In ultrabasic rocks 300 g/t, in basic rocks 9 kg/t, in acidic rocks 2.3 kg/t, in clays and shales 4.5 kg/t. In the earth's crust, titanium is almost always tetravalent and is present only in oxygen compounds. It does not occur in free form. Titanium under conditions of weathering and precipitation has a geochemical affinity for Al2O3. It is concentrated in bauxites of the weathering crust and in marine clayey sediments. The transfer of titanium is carried out in the form of mechanical fragments of minerals and in the form of colloids. Up to 30% TiO2 by weight accumulates in some clays. Titanium minerals are resistant to weathering and form large concentrations in placers. More than 100 minerals containing titanium are known. The most important of them are: rutile TiO2, ilmenite FeTiO3, titanomagnetite FeTiO3 + Fe3O4, perovskite CaTiO3, titanite CaTiSiO5. There are primary titanium ores - ilmenite-titanomagnetite and placer - rutile-ilmenite-zircon.

Main ores: ilmenite (FeTiO3), rutile (TiO2), titanite (CaTiSiO5).

In 2002, 90% of the mined titanium was used for the production of titanium dioxide TiO2. World production of titanium dioxide was 4.5 million tons per year. Proven reserves of titanium dioxide (without Russian Federation) are about 800 million tons. For 2006, according to the US Geological Survey, in terms of titanium dioxide and excluding Russian Federation, the reserves of ilmenite ores are 603-673 million tons, and rutile - 49.7-52.7 million tons. Thus, at the current rate of production of the world's proven reserves of titanium (excluding the Russian Federation) will last more than 150 years.

Russia has the world's second largest reserves of titanium after China. The mineral resource base of titanium in the Russian Federation consists of 20 deposits (of which 11 are primary and 9 are alluvial), fairly evenly dispersed throughout the country. The largest of the explored deposits (Yaregskoye) is located 25 km from the city of Ukhta (Komi Republic). The reserves of the deposit are estimated at 2 billion tons of ore with an average titanium dioxide content of about 10%.

The world's largest producer of titanium Russian organization"VSMPO-AVISMA".

As a rule, the starting material for the production of titanium and its compounds is titanium dioxide with a relatively small amount of impurities. In particular, it can be a rutile concentrate obtained during the beneficiation of titanium ores. However, the reserves of rutile in the world are very limited, and the so-called synthetic rutile or titanium slag, obtained during the processing of ilmenite concentrates, is more often used. To obtain titanium slag, ilmenite concentrate is reduced in an electric arc furnace, while iron is separated into a metal phase (), and not reduced titanium oxides and impurities form a slag phase. Rich slag is processed by the chloride or sulfuric acid method.

In pure form and in the form of alloys

Titanium monument to Gagarin on Leninsky Prospekt in Moscow

metal is used in: chemical industry(reactors, pipelines, pumps, pipeline fittings), military industry(body armor, armor and fire barriers in aviation, submarine hulls), industrial processes (desalination plants, processes pulp and paper), automotive industry, agricultural industry, food industry, piercing jewelry, medical industry (prostheses, osteoprostheses), dental and endodontic instruments, dental implants, sporting goods, jewelry trade items (Alexander Khomov), mobile phones, light alloys etc. It is the most important structural material in aircraft, rocket and shipbuilding.

Titanium is an alloying addition in many alloyed steels and most special alloys.

Nitinol (nickel-titanium) is a shape memory alloy used in medicine and technology.

Titanium aluminides are very resistant to oxidation and heat-resistant, which in turn determined their use in aviation and automotive industry as structural materials.

Titanium is one of the most common getter materials used in high vacuum pumps.

White titanium dioxide (TiO2) is used in paints (such as titanium white) as well as in the manufacture of paper and plastics. Food additive E171.

Organotitanium compounds (eg tetrabutoxytitanium) are used as a catalyst and hardener in the chemical and paint industries.

Inorganic titanium compounds are used in the chemical, electronic, glass fiber industries as additives or coatings.

Titanium carbide, titanium diboride, titanium carbonitride are important components of superhard materials for metal processing.

Titanium nitride is used to coat tools, church domes and in the manufacture of costume jewelry, because. has a color similar to .

Barium titanate BaTiO3, lead titanate PbTiO3, and a number of other titanates are ferroelectrics.

There are many titanium alloys with different metals. Alloying elements are divided into three groups, depending on their effect on the temperature of polymorphic transformation: beta stabilizers, alpha stabilizers and neutral hardeners. The former lower the transformation temperature, the latter increase it, and the latter do not affect it, but lead to solution hardening of the matrix. Examples of alpha stabilizers: , oxygen, carbon, nitrogen. Beta stabilizers: molybdenum, vanadium, iron, chromium, Ni. Neutral hardeners: zirconium, silicon. Beta stabilizers, in turn, are divided into beta-isomorphic and beta-eutectoid-forming. The most common titanium alloy is the Ti-6Al-4V alloy (VT6 in the Russian classification).

In 2005 firm titanium corporation has published the following estimate of titanium consumption in the world:

13% - paper;

7% - mechanical engineering.

$15-25 per kilo, depending on purity.

The purity and grade of rough titanium (titanium sponge) is usually determined by its hardness, which depends on the content of impurities. The most common brands are TG100 and TG110.

The consumer goods market segment is currently the fastest growing segment of the titanium market. While 10 years ago this segment was only 1-2 of the titanium market, today it has grown to 8-10 of the market. Overall, titanium consumption in the consumer goods industry grew at about twice the rate of the entire titanium market. The use of titanium in sports is the longest running and holds the largest share of the use of titanium in consumer products. The reason for the popularity of titanium in sports equipment is simple - it allows you to get a ratio of weight and strength superior to any other metal. The use of titanium in bicycles began about 25-30 years ago and was the first use of titanium in sports equipment. Ti3Al-2.5V ASTM Grade 9 alloy tubes are mainly used. Other parts made from titanium alloys include brakes, sprockets and seat springs. The use of titanium in the manufacture of golf clubs first began in the late 80s and early 90s by club manufacturers in Japan. Prior to 1994-1995, this application of titanium was virtually unknown in the US and Europe. That changed when Callaway introduced its Ruger titanium stick, called the Great Big Bertha, to the market. Due to the obvious benefits and well-thought-out marketing from Callaway, titanium sticks became an instant hit. Within a short period of time, titanium clubs have gone from the exclusive and expensive inventory of a small group of speculators to being widely used by most golfers while still being more expensive than steel clubs. I would like to cite the main, in my opinion, trends in the development of the golf market; it has gone from high-tech to mass production in a short 4-5 years, following the path of other industries with high labor costs such as the production of clothing, toys and consumer electronics, the production of golf clubs went into countries with the cheapest labor first to Taiwan, then to China, and now factories are being built in countries with even cheaper labor, such as Vietnam and Thailand, titanium is definitely used for drivers, where its superior qualities give a clear advantage and justify a higher price. However, titanium has not yet found very widespread use on subsequent clubs, as the significant increase in costs is not matched by a corresponding improvement in the game. Currently, drivers are mainly produced with a forged striking face, a forged or cast top and a cast bottom. Recently, the Professional Golf ROA allowed to increase the top the limit of the so-called return factor, in connection with which all club manufacturers will try to increase the spring properties of the striking surface. To do this, it is necessary to reduce the thickness of the impact surface and use stronger alloys for it, such as SP700, 15-3-3-3 and VT-23. Now let's focus on the use of titanium and its alloys on other sports equipment. Race bike tubes and other parts are made from ASTM Grade 9 Ti3Al-2.5V alloy. A surprisingly significant amount of titanium sheet is used in the manufacture of scuba diving knives. Most manufacturers use Ti6Al-4V alloy, but this alloy does not provide blade edge durability like other stronger alloys. Some manufacturers are switching to using BT23 alloy.

Many are interested in a slightly mysterious and not fully understood titanium - a metal whose properties are somewhat ambiguous. Metal is both the strongest and the most brittle.

The strongest and most brittle metal

It was discovered by two scientists with a difference of 6 years - the Englishman W. Gregor and the German M. Klaproth. The name of the titan is associated, on the one hand, with the mythical titans, supernatural and fearless, on the other hand, with Titania, the queen of the fairies.
This is one of the most common materials in nature, but the process of obtaining a pure metal is particularly difficult.

22 chemical element D. Mendeleev's table Titanium (Ti) belongs to the 4th group of the 4th period.

The color of titanium is silvery white with a pronounced luster. Its highlights shimmer with all the colors of the rainbow.

It is one of the refractory metals. It melts at +1660°C (±20°). Titanium is paramagnetic: it is not magnetized in a magnetic field and is not pushed out of it.
The metal is characterized by low density and high strength. But the peculiarity of this material lies in the fact that even minimal impurities of other chemical elements radically change its properties. In the presence of an insignificant fraction of other metals, titanium loses its heat resistance, and a minimum of non-metallic substances in its composition make the alloy brittle.
This feature determines the presence of 2 types of material: pure and technical.

Pure titanium is used where a very light substance is required that can withstand heavy loads and ultra-high temperature ranges.
Technical material is used where parameters such as lightness, strength and resistance to corrosion are valued.

The substance has the property of anisotropy. This means that the metal can change its physical characteristics based on the applied force. This feature should be taken into account when planning the use of the material.

Titanium loses its strength at the slightest presence of impurities of other metals in it.

Conducted studies of the properties of titanium under normal conditions confirm its inertness. The substance does not react to elements in the surrounding atmosphere.
The change in parameters begins when the temperature rises to +400°C and above. Titanium reacts with oxygen, can ignite in nitrogen, absorbs gases.
These properties make it difficult to obtain a pure substance and its alloys. Titanium production is based on the use of expensive vacuum equipment.

Titanium and competition with other metals

This metal is constantly compared with aluminum and iron alloys. Many of the chemical properties of titanium are significantly better than those of competitors:

In terms of mechanical strength, titanium surpasses iron by 2 times, and aluminum by 6 times. Its strength increases with decreasing temperature, which is not observed in competitors.
Anticorrosive characteristics of titanium are significantly higher than those of other metals.
At ambient temperatures, the metal is absolutely inert. But when the temperature rises above +200°C, the substance begins to absorb hydrogen, changing its characteristics.
At higher temperatures, titanium reacts with other chemical elements. It has a high specific strength, which is 2 times higher than the properties of the best iron alloys.
The anti-corrosion properties of titanium significantly exceed those of aluminum and stainless steel.
The substance is a poor conductor of electricity. Titanium has a resistivity 5 times that of iron, 20 times that of aluminum, and 10 times that of magnesium.
Titanium is characterized by low thermal conductivity, this is due to the low coefficient of thermal expansion. It is 3 times less than that of iron, and 12 times less than that of aluminum.

How is titanium obtained?

The material takes 10th place in terms of distribution in nature. There are about 70 minerals containing titanium in the form of titanic acid or its dioxide. The most common of them and containing a high percentage of metal derivatives:

ilmenite;
rutile;
anatase;
perovskite;
brookite.

The main deposits of titanium ores are located in the USA, Great Britain, Japan, large deposits they are open in Russia, Ukraine, Canada, France, Spain, Belgium.

Titanium mining is an expensive and labor-intensive process

Getting metal from them is very expensive. Scientists have developed 4 ways to produce titanium, each of which is working and effectively used in industry:

Magnesium method. The extracted raw materials containing titanium impurities are processed and titanium dioxide is obtained. This substance undergoes chlorination in mine or salt chlorinators at increased temperature regime. The process is very slow and is carried out in the presence of a carbon catalyst. In this case, solid dioxide is converted into a gaseous substance - titanium tetrachloride. The resulting material is reduced by magnesium or sodium. The alloy formed during the reaction is subjected to heating in a vacuum unit to ultrahigh temperatures. As a result of the reaction, evaporation of magnesium and its compounds with chlorine occurs. At the end of the process, a sponge-like material is obtained. It is melted and high quality titanium is obtained.
Hydride-calcium method. Ore is subjected chemical reaction and get titanium hydride. The next stage is the separation of the substance into components. Titanium and hydrogen are released during heating in vacuum plants. At the end of the process, calcium oxide is obtained, which is washed with weak acids. The first two methods relate to industrial production. They make it possible to obtain pure titanium in the shortest possible time at relatively low costs.
electrolysis method. Titanium compounds are subjected to high current. Depending on the feedstock, the compounds are divided into components: chlorine, oxygen and titanium.
Iodide method or refining. Titanium dioxide obtained from minerals is doused with iodine vapor. As a result of the reaction, titanium iodide is formed, which is heated to a high temperature - + 1300 ... + 1400 ° C and act on it electric shock. At the same time, components are isolated from the source material: iodine and titanium. The metal obtained by this method has no impurities and additives.

Areas of use

The use of titanium depends on the degree of its purification from impurities. The presence of even a small amount of other chemical elements in the composition of a titanium alloy radically changes its physical and mechanical characteristics.

Titanium with a certain amount of impurities is called technical. It has high rates of corrosion resistance, it is light and very durable material. Its application depends on these and other indicators.

In the chemical industry titanium and its alloys are used to manufacture heat exchangers, pipes of various diameters, fittings, housings and parts for pumps for various purposes. The substance is indispensable in places where high strength and resistance to acids are required.
On transport titanium is used for the manufacture of parts and assemblies of bicycles, cars, railway cars and trains. The use of the material reduces the weight of rolling stock and cars, makes bicycle parts lighter and stronger.
Titanium is important in the naval department. Parts and elements of hulls for submarines, propellers for boats and helicopters are made from it.
In the construction industry zinc-titanium alloy is used. It is used as a finishing material for facades and roofs. This very strong alloy has an important property: it can be used to make architectural details of the most fantastic configuration. It can take any form.
In the last decade, titanium has been widely used in the oil industry. Its alloys are used in the manufacture of equipment for ultra-deep drilling. The material is used for the manufacture of equipment for oil and gas production on the offshore shelves.

Titanium has a very wide range of applications.

Pure titanium has its uses. It is needed where resistance to high temperatures is required and at the same time the strength of the metal must be maintained.

It is applied in :

aircraft and space industry for the manufacture of skin parts, hulls, fasteners, chassis;
medicine for prosthetics and the manufacture of heart valves and other devices;
technique for working in the cryogenic region (here they use the property of titanium - with a decrease in temperature, the strength of the metal increases and its plasticity is not lost).

In percentage terms, the use of titanium for the production of various materials looks like this:

60% is used for the manufacture of paint;
plastic consumes 20%;
13% is used in paper production;
mechanical engineering consumes 7% of the resulting titanium and its alloys.

Raw materials and the process of obtaining titanium are expensive, the costs of its production are compensated and paid off by the service life of products from this substance, its ability not to change its appearance over the entire period of operation.

TITANIUM AND ITS ALLOYS

Titanium belongs to the group of refractory metals, its melting point is 1668°C. Titanium has two allotropic modifications α and ß. Modification α is low-temperature and exists when heated to 882.5°C, has a hexagonal lattice. At a temperature of 882.5°C, the α-modification transforms into the ß-modification, which has a body-centered cubic lattice. With the transition of α-titanium to ß-titanium, the volume of the metal decreases somewhat, and the electrical conductivity increases abruptly.

The main advantages of titanium are density (4.5 g/cm3), high corrosion resistance and high mechanical strength. Despite the fact that titanium is chemically very active and easily reacts with a large number of elements, it has a high corrosion resistance due to the protective effect of a strong and dense oxide film formed on its surface. In most corrosive environments, titanium and its alloys have a higher resistance than acid-resistant steels and aluminum.

With the introduction of alloying elements, it is possible to obtain alloys with high mechanical strength. The main alloying elements are Al, Sn, Mn, Cr, Mo, V. Alloying elements affect the stability of titanium allotropic modifications. In accordance with the influence of alloying elements on allotropic transformations, titanium alloys are classified according to their structure as follows:

1) a-titanium alloys, the structure of which consists of an α-phase (for example, alloy VT5-1);

2) α + ß - alloys in the structure of which both phases are present (VTZ-1, VT6);

3) ß - alloys, the structure of which consists of a mechanically stable ß - phase (VT15); two-phase (α + ß)-alloys and ß-alloys, in contrast to α-alloys, are strengthened by heat treatment.

Titanium alloys have not only higher mechanical strength, but also greater corrosion resistance than pure titanium. Titanium and its alloys lend themselves well to hot and cold working by pressure, are well welded in an inert environment, but have low antifriction properties and, compared with steel, are less machined by cutting.

Titanium alloys are widely used in aviation and rocket technology, in the chemical industry, non-ferrous metallurgy and other industries where the use of titanium alloys is determined by their valuable anti-corrosion properties. Thus, titanium heat exchangers operating in nitric acid have a corrosion rate 60 times lower than similar stainless steel heat exchangers. Titanium is used to make equipment for the chlorine industry, propellers, etc.

Titanium (Ti) (Titanium) - a chemical element with serial number 22 in the periodic system of elements of D.I. Mendeleev, atomic weight 47.88, light silvery-white metal. Density 4, 51 g/s m³, tpl.=1668+ (-)5°С, tbp.=3260°С.

In terms of density and specific heat capacity, titanium occupies an intermediate position between the two main structural metals: aluminum and iron. It is also worth noting that its mechanical strength is about twice that of pure iron and almost six times that of aluminum. But titanium can actively absorb oxygen, nitrogen and hydrogen, which sharply reduce the plastic properties of the metal. With carbon, titanium forms refractory carbides with high hardness.

Titanium has a low thermal conductivity, which is 13 times less than the thermal conductivity of aluminum and 4 times less than iron. The coefficient of thermal expansion at room temperature is relatively small, it increases with increasing temperature.

The elastic moduli of titanium are small and exhibit significant anisotropy. As the temperature rises to 350°C, the elastic moduli decrease almost linearly. The small value of the elasticity moduli of titanium is its significant drawback, since in some cases, in order to obtain sufficiently rigid structures, it is necessary to use large sections of products compared to those that follow from the strength conditions.

Titanium has a rather high electrical resistivity, which, depending on the content of impurities, ranges from 42·10-8 to 80·10-6 Ohm·cm. At temperatures below 0.45 K, it becomes a superconductor.

Titanium is a paramagnetic metal. In paramagnetic substances, the magnetic susceptibility usually decreases when heated. Titanium is an exception to this rule - its susceptibility increases significantly with temperature.

For commercial titanium grades VT-00 and VT1-0, the density is approximately 4.32 g/s m³. Titanium and titanium alloys combine lightness, strength, high corrosion resistance, low coefficient of thermal expansion, the ability to work in a wide temperature range (from -290°C to 600°C).

The metal has a number of useful properties that make it one of the main materials in certain industries. Rolled titanium is used in rocket and aircraft building, chemical industry, shipbuilding, mechanical engineering

For example, titanium sheet and titanium rod are used in the creation of nuclear submarine hulls;
titanium pipes are used in the chemical industry due to their high anti-corrosion characteristics and chemical inertness to reagents;
Titanium wire is used as a filler wire to create frameworks, molds, bodies of strategic titanium alloys.

titanium wire often used in the medical industry, in particular dentistry. The useful properties of rolled titanium products include high mechanical strength, corrosion resistance (resistant in many chemically active environments), heat resistance (tmelt = 1668 ° C), as well as low density (4.505 g / cm 3). The main physical and chemical properties of titanium can be viewed in this table. But titanium also has its drawbacks. One of the main disadvantages is the high cost of production. Titanium melting can only be carried out in a vacuum or an inert gas environment, because. this metal actively interacts (especially in the liquid state) with all the gases that make up the atmosphere. Also, titanium products have poor anti-friction properties, high susceptibility to hydrogen embrittlement and salt corrosion, poor machinability and weldability.

The basis for the production of technical titanium and its alloys is a titanium sponge obtained by the magnesium-thermal method. Titanium sponge is a porous gray substance with a bulk density of 1.5-2.0 g/cm 3 and a very high viscosity.

Depending on the content of impurities, technical titanium is divided into several grades: GR1 (the purest titanium), GR2 (more polluted).

Titanium alloys

Titanium alloys play an important role in aviation technology, where the aim is to obtain the lightest design combined with the required strength. Titanium is light compared to other metals, but at the same time it can work at high temperatures (see Fig. 2). Titanium alloys are used to make skin, fastening parts, a power set, chassis parts, and various units. Also, these materials are used in the construction of aircraft jet engines. This allows you to reduce their weight by 10-25%. Titanium alloys are used to produce compressor disks and blades, air intake and guide vane parts, and fasteners.

Titanium and its alloys are also used in rocket science. In view of the short-term operation of the engines and the rapid passage of dense layers of the atmosphere in rocket science, the problems of fatigue strength, static endurance, and partly creep are largely removed.

Technical titanium is not suitable for aviation applications due to its insufficiently high heat resistance, but due to its exceptionally high corrosion resistance, in some cases it is indispensable in the chemical industry and shipbuilding. So it is used in the manufacture of compressors and pumps for pumping such aggressive media as sulfuric and hydrochloric acid and their salts, pipelines, valves, autoclaves, various containers, filters, etc. Only titanium has corrosion resistance in media such as wet chlorine, aqueous and acidic solutions of chlorine, therefore equipment for the chlorine industry is made from this metal. Titanium is used to make heat exchangers that operate in corrosive environments, for example, in nitric acid (not fuming). In shipbuilding, titanium is used for the manufacture of propellers, plating of ships, submarines, torpedoes, etc. Shells do not stick to titanium and its alloys, which sharply increase the resistance of the vessel when it moves.

Titanium alloys are promising for use in many other applications, but their use in technology is constrained by the high cost and scarcity of titanium.

Currently, a fairly large variety of titanium alloys is known, differing in chemical composition, mechanical and technological properties. The most commonly used alloying elements in titanium alloys are aluminum, vanadium, molybdenum, manganese, chromium, silicon, tin, zirconium, and iron.

Titanium alloy VT5 contains, in addition to titanium, 5% aluminum. It has higher strength properties compared to titanium, but its manufacturability is low. The alloy is forged, rolled, stamped and well welded.

From titanium (alloy) VT5, titanium rods, titanium wire and titanium pipes are obtained. It is used in the manufacture of parts operating at temperatures up to 400 ° C.

Titanium alloy VT5-1 in addition to 5% aluminum contains 2-3% tin. Tin improves its technological properties. Titanium alloy VT5-1 is used to manufacture all types of semi-finished products obtained by pressure treatment: titanium sheets, plates, forgings, stampings, profiles, titanium pipes and titanium wire. It is intended for the manufacture of products operating in a wide temperature range: from cryogenic to 450 °C.

Titanium alloys OT4 and OT4-1, in addition to titanium, contain aluminum and manganese. They have high technological plasticity (they are well deformed in hot and cold states) and are well welded by all types of welding. Titanium of these grades is mainly intended for the production of titanium sheets, strips and strips, as well as titanium rods, forgings, profiles and titanium pipes. From titanium alloys OT4 and OT4-1, parts are made using welding, stamping and bending, operating up to a temperature of 350 ° C. These alloys have disadvantages: 1) relatively low strength and heat resistance; 2) a greater tendency to hydrogen embrittlement. In the PT3V alloy, manganese is replaced by vanadium.

Titanium alloy VT20 was developed as a stronger sheet alloy compared to VT5-1. Hardening of the VT20 alloy is due to its alloying, in addition to aluminum, with zirconium and small amounts of molybdenum and vanadium. The technological plasticity of the VT20 alloy is low due to the high aluminum content. Titanium BT20 is characterized by high heat resistance. It welds well, the strength of the welded joint is equal to the strength of the base metal. The alloy is intended for the manufacture of products that operate for a long time at temperatures up to 500 °C.

Titanium alloy VT3-1 belongs to the system Ti - Al - Cr - Mo - Fe - Si. It is usually subjected to isothermal annealing. Such annealing provides the highest thermal stability and maximum ductility. Alloy VT3-1 is one of the most mastered in the production of alloys. It is designed for continuous operation at 400 - 450 °C; it is a heat-resistant alloy with fairly high long-term strength. Titanium bars, profiles, plates, forgings, stampings are supplied from it.

Titanium and its alloys

Titanium melts at a temperature of 1660°C, allotropic, harmful impurities N, C, O, H. The TiO2 film protects titanium from oxidation, corrosion in any water, some acids. It is melted, poured, welded in an argon environment, and subjected to OMD. Sheets, pipes, profiles, and wires are made from titanium. Its alloys with Fe, Al, Mn, Cr, Sn, V, Si, Ga, Ge, La, Nb, Ta, Zr, W, Mo, Co, Si have increased strength, heat resistance, corrosion resistance. Titanium alloys are heat treated.

Titanium alloys are deformed, cast, made from powders, hardened, tempered, well machined.

Wrought titanium alloys:

− ά – alloys: VT5, VT-5-1, OT-4;

− ά – β alloys: VT-6, VT14, VT8; BT15

Cast alloys: VT5L, VT6L, VT14L, VT3-1L

Powdered titanium alloys are obtained from powders by pressing, they are strong and ductile.

Titanium alloys are used to make the skin of aircraft, sea vessels, submarines, shells of missiles, engines, parts of turbines, compressors, propellers, cylinders for liquefied gases, containers for chemicals and many other products. Titanium alloys can be subjected to, annealing, quenching, aging and cold treatment. Annealing of α - alloys is carried out at 800 - 850 0С, and α + β - alloys - at 750 -800 0С. Vacuum annealing makes it possible to reduce the hydrogen content, which leads to an increase in impact strength, a decrease in damage and cracking.

At a high concentration of the alloying element and hardening, a martensitic α׀׀ - phase with a rhombic lattice and ω - a phase with a hexagonal structure appears. In the process of aging of hardened alloys, they harden due to the decomposition of α׀׀ and β - phases. Wrought titanium alloys are well processed by pressure in a hot state, welded, and have high corrosion resistance.

The characteristic features of titanium are low density 4.51 kg/dm3, high strength, which is maintained up to 6000C, and corrosion resistance. They define the scope of its application. Titanium alloys combine high strength (σВ= 800-1500 MPa) with good ductility (δ= 12-25%), relatively good heat resistance up to 600-7000С, high corrosion resistance in many aggressive media except HCL, HF. α-titanium alloys do not age and are used in cryogenic installations up to helium temperatures (-2720C). One of the disadvantages of titanium alloys is their poor machinability by cutting tools.

Titanium. The invention of titanium. Titanium and its alloys.

The discoverer of titanium is considered to be 28-year-old English monk William Gregor. In 1790, while conducting mineralogical surveys in his parish, he drew attention to the prevalence and unusual properties of black sand in the valley of Menaken in the south-west of England and began to explore it. In the sand, the priest found grains of a black shiny mineral, attracted by an ordinary magnet. Obtained in 1925 by Van Arkel and de Boer by the iodide method, the purest titanium turned out to be a ductile and technological metal with many valuable properties that attracted the attention of a wide range of designers and engineers. In 1940, Croll proposed a magnesium-thermal method for extracting titanium from ores, which is still the main one at the present time. In 1947, the first 45 kg of commercially pure titanium were produced.

Titanium also forms compounds with hydrogen (hydrides), nitrogen (nitrides), carbon (carbides), phosphorus (phosphides), arsenic (arsides), as well as compounds with many metals - intermetallic compounds. Titanium forms not only simple, but also numerous complex compounds; many of its compounds with organic substances are known. As can be seen from the list of compounds in which titanium can participate, it is chemically very active. And at the same time, titanium is one of the few metals with exceptionally high corrosion resistance: it is practically eternal in the air, in cold and boiling water, it is very resistant in sea water, in solutions of many salts, inorganic and organic acids. In terms of its corrosion resistance in sea water, it surpasses all metals, with the exception of noble ones - gold, platinum, etc., most types of stainless steel, nickel, copper and other alloys. In water, in many aggressive environments, pure titanium is not subject to corrosion. Resists titanium and erosion corrosion resulting from a combination of chemical and mechanical effects on the metal. In this regard, it is not inferior to the best grades of stainless steels, copper-based alloys and other structural materials. Titanium also resists fatigue corrosion well, which often manifests itself in the form of violations of the integrity and strength of the metal (cracking, local corrosion centers, etc.). The behavior of titanium in many aggressive environments, such as nitrogen, hydrochloric, sulfuric, "aqua regia" and other acids and alkalis, is surprising and admirable for this metal.

Titanium is a light metal, its density at 0°C is only 4.517 g/cm8, and at 100°C it is 4.506 g/cm3. Titanium belongs to the group of metals with a specific gravity of less than 5 g/cm3. This includes all alkali metals (sodium, cadium, lithium, rubidium, cesium) with a specific gravity of 0.9–1.5 g/cm3, magnesium (1.7 g/cm3), aluminum (2.7 g/cm3) and etc. Titanium is more than 1.5 times heavier than aluminum, and in this, of course, it loses to it, but it is 1.5 times lighter than iron (7.8 g/cm3). However, occupying an intermediate position between aluminum and iron in terms of specific density, titanium surpasses them many times over in its mechanical properties.). Titanium has a significant hardness: it is 12 times harder than aluminum, 4 times harder than iron and copper. Another important characteristic of a metal is its yield strength. The higher it is, the better the parts made of this metal resist operational loads. The yield strength of titanium is almost 18 times higher than that of aluminum. The specific strength of titanium alloys can be increased by a factor of 1.5–2. Its high mechanical properties are well preserved at temperatures up to several hundred degrees. Pure titanium is suitable for all types of processing in hot and cold states: it can be forged like iron, drawn and even made into wire, rolled into sheets, tapes, and foils up to 0.01 mm thick.

Today, titanium alloys are widely used in aviation technology. Titanium alloys were first used on an industrial scale in the construction of aircraft jet engines. The use of titanium in the design of jet engines makes it possible to reduce their weight by 10...25%. In particular, compressor discs and blades, air intake parts, guide vanes and fasteners are made from titanium alloys. Titanium alloys are indispensable for supersonic aircraft. The increase in aircraft flight speeds led to an increase in the temperature of the skin, as a result of which aluminum alloys no longer meet the requirements imposed by aviation technology at supersonic speeds. The skin temperature in this case reaches 246...316 °C. Under these conditions, titanium alloys turned out to be the most acceptable material. In the 70s, the use of titanium alloys for the airframe of civil aircraft increased significantly. In the medium-haul aircraft TU-204, the total mass of parts made of titanium alloys is 2570 kg. The use of titanium in helicopters is gradually expanding, mainly for parts of the main rotor system, drive, and control system. An important place is occupied by titanium alloys in rocket science.
Due to the high corrosion resistance in sea water, titanium and its alloys are used in shipbuilding for the manufacture of propellers, ship plating, submarines, torpedoes, etc. Shells do not stick to titanium and its alloys, which sharply increase the resistance of the vessel when it moves. Gradually, the areas of application of titanium are expanding. Titanium and its alloys are used in the chemical, petrochemical, pulp and paper and food industries, non-ferrous metallurgy, power engineering, electronics, nuclear technology, electroplating, in the manufacture of weapons, for the manufacture of armor plates, surgical instruments, surgical implants, desalination plants, racing car parts , sports equipment (golf clubs, climbing equipment), watch parts and even jewelry. Nitriding of titanium leads to the formation of a golden film on its surface, which is not inferior in beauty to real gold.

Titanium and its alloys possess high corrosion resistance in atm. conditions, fresh and sea water, solutions of most chlorides, hypochlorites, chlorine dioxide and many others. mineral salts to-t both at normal and at elevated temperatures. Titanium and its alloys also have high corrosion resistance in acidic oxidizes. environments (nitric and chromic to - you, etc.) and in solution of alkalis. In non-oxidizing, acids (sulphuric, hydrochloric), titanium has a satisfactory effect. corrosion resistance at normal temp-pax and concentration to-t up to 8-10%. With an increase in temperature, concentration of to-t and alkalis, the corrosion rate of titanium increases sharply. For sulfuric acid, two maximum corrosion rates are observed, corresponding to 40 and 75% concentrations. In 40% sulfuric acid, the corrosion process proceeds with the release of hydrogen; this type of acid is characterized by the highest electrical conductivity and maximum concentration of hydrogen ions. In a 75% solution, the corrosion process is accompanied by the reduction of sulfuric acid to H3S and free sulfur, and at high concentrations (80-90%) SO2 and free sulfur are released. In phosphoric acid, titanium is relatively more resistant and retains high corrosion resistance up to a 30% solution; with increasing concentration, the corrosion rate increases. Additives of oxidizing agents (K2Cr207; HNOs; Fe + + +; Cu + +) sharply reduce the corrosion rate of titanium and its alloys in hydrochloric and sulfuric acids.

Titanium: α- titanium- hexagonal, β- titanium- cubic...