Titanium is a two-phase alloy, has a good overall performance

Titanium is a two-phase alloy, has a good overall performance, good organizational stability, good toughness, ductility and high temperature deformation properties, can better thermal pressure processing, can be quenched, aging of the alloy strengthening. Strength after the heat treatment higher than the annealed state of about 50% to 100%; high temperature strength, long-term work at a temperature of 400 ℃ ~ 500 ℃, the thermal stability is inferior α titanium alloy.
The most commonly used three kinds of titanium alloy is α and α + β titanium alloy; α titanium alloy machinability best, α + β titanium followed, β titanium worst. α titanium codenamed TA, βtitanium pipe codenamed TB, α + β titanium codenamed TC.
Titanium can be divided according to use heat-resistant alloys, high-strength alloys, corrosion resistant alloy (Ti - molybdenum, titanium - palladium alloys, etc.), low alloy and alloy special features. Table typical composition and performance of the alloy.
Titanium heat treatment can be obtained by adjusting the heat treatment process and the organization of different phases. Generally considered fine equiaxed has good ductility, thermal stability and fatigue strength; needle tissue has a high rupture strength, creep strength and fracture toughness; equiaxed and needle hybrid organization has good overall performance.

Titanium Industry Development History

Titanium Industry Development History
1791 British clergyman W. Gregor (Gregor) discovered a new metal elements in black magnetite. In 1795 the German chemist M. H. Carat Preuss (Klaproth) rutile in the study also found that the elements, and is named after the Greek god of the Titans. 1910 American scientist M. A. Hunter (Hunter) for the first time with a sodium reduction TiCI: Preparation of titanium bar. 1940 Luxembourg scientist W. J. Kroll (kroll) with magnesium reduction TiCl: prepared titanium. Since then, the magnesium reduction method (also known as the Kroll process) and sodium reduction method (also known as Hunt France) became the industrial production of titanium sponge method. In 1948 the United States out of the magnesium reduction process 2t titanium sponge, from reaching industrial scale. Subsequently, the United Kingdom, Japan, the former Soviet Union and China have also entered the industrial production, one of the major producing country of the former Soviet Union titanium, Japan and the United States.
     Titanium is a new metal, because it has a series of excellent features, aviation, aerospace, chemical, petroleum, metallurgy, light industry, power, desalination, ships and everyday appliances are widely used in industrial production, which is hailed for modern metal. titanium bolts metal production from 1948 has only half a century of history, it is accompanied by the aerospace industry and developed new industries. Its development has withstood several ups and downs, this is because titanium and aircraft industry-related reasons. Overall, however, the speed of development of titanium is very fast, it is more than any other non-ferrous metals pace of development. This can be seen from the development of the world's titanium sponge industry: titanium sponge production scale of the 1960s 60kt / a, 70 years for 1lOkt / a, 80 years of 130kt / a, to 1992 has reached 140kt / a. Actual production in 1990 reached record levels, as 105kt / a

Titanium alloy is a titanium-based alloy by adding other elements

Titanium alloy is a titanium-based alloy by adding other elements. There are two isomeric titanium crystal:
Below 882 ℃ for α hcp titanium wire, more than 882 ℃ for the body-centered cubic β titanium.
Alloying elements according to their impact on the phase transition temperature can be divided into three categories:
① stable α phase, increase the phase transition temperature of the elements of α stabilizing element, aluminum, carbon, oxygen and nitrogen. Which is the main alloying elements aluminum alloy, improve its normal and high temperature strength of the alloy, reduce the proportion of the elastic modulus increases obviously.
② stable β-phase, reducing the element of the phase transition temperature of β stabilizing element, and can be divided isomorphic and eutectoid two. The former has molybdenum, niobium, vanadium and the like; the latter are chromium, manganese, copper, iron, silicon and the like.
③ small element of the phase transition temperature is neutral elements, zirconium and tin. Oxygen, nitrogen, carbon and hydrogen are the major impurity titanium. Oxygen and nitrogen in the α phase has a greater solubility of titanium significant strengthening effect, but the plastic drop. Typically a predetermined content of oxygen and nitrogen in titanium 0.15 to 0.2% and 0.04% to 0.05% or less, respectively. The solubility of hydrogen in α phase is very small, titanium dissolved in excess hydride hydrogen will produce the alloy brittle. Titanium is usually hydrogen content control 0.015%. Hydrogen was dissolved in titanium sheet is reversible, can be removed by vacuum annealing.

Titanium is allotrope, melting point 1668 ℃, showed a close-packed hexagonal lattice structure

Titanium is allotrope, melting point 1668 ℃, showed a close-packed hexagonal lattice structure, called α titanium alloys at temperatures below 882 ℃; body-centered cubic lattice structure at above 882 ℃ was called β titanium. The use of the different characteristics of the two titanium structures, adding appropriate alloying elements, so that the phase transition temperature and relative content of different tissues obtained by gradually changing the titanium (titanium alloys). At room temperature, there are three titanium matrix organization, titanium will be divided into the following three categories: α alloy, (α + β) alloys and β alloys.
α titanium
It is a single phase alloy consisting of α-phase solid solution, either at ambient temperatures or at higher temperatures the practical application, are the α phase, organizational stability, wear resistance higher than that of pure titanium, high resistance to oxidation. At a temperature of 500 ℃ ~ 600 ℃, and maintains its strength and creep resistance, but can not be heat strengthened, not high temperature strength.
β titanium alloy
titanium tube is a single-phase alloy consisting of β-phase solid solution, that is not heat-treated after having a high strength, hardening, aging alloy has been further strengthened, the room temperature strength of up to 1372 ~ 1666 MPa; but poor thermal stability, and should not be used at high temperatures .
α + β titanium alloy

Titanium alloys at low and ultra-low temperature

Titanium alloys at low and ultra-low temperature, retains its mechanical properties. Low temperature performance, low interstitial elements of titanium bar, as TA7, at -253 ℃ still maintain a certain plasticity. Thus, low-temperature titanium alloy is also an important structural materials.
Large chemical activity
Chemical activity of titanium is large, a strong chemical reaction with atmospheric O, N, H, CO, CO2, water vapor, ammonia and the like. Carbon content greater than 0.2%, it will form a hard TiC in the titanium alloy; at higher temperatures, and also the role of N forms TiN hard surface; at above 600 ℃, the high hardness of hardened layer is formed of titanium absorbs oxygen ; hydrogen content increased, brittle layer will form. Absorbing gas produced brittle surface to a depth of 0.1 ~ 0.15 mm, the degree of hardening of 20% to 30%. Chemical affinity of titanium is also large, easy and sticking friction surface.
Small thermal elasticity
Thermal conductivity of titanium bolts λ = 15.24W / (mK) approximately 1/4 of nickel, iron 1/5, 1/14 aluminum, while the thermal conductivity of various titanium alloys decreased by 50% than the thermal conductivity of titanium. Elastic modulus was about 1/2 of the titanium alloy for steel, so the poor rigidity, deformation, and should not be made thin-walled elongated rod member, the machined surface when cutting a large amount of spring back, the stainless steel is about 2 to 3 times, causing severe tool flank friction, adhesion, adhesive wear.

Titanium has a high strength and density and small, good mechanical

Titanium has a high strength and density and small, good mechanical properties, good toughness and corrosion resistance. In addition, poor process performance titanium distributors alloy, machining difficulties in thermal processing, and very easy to absorb carbon hydrogen nitrogen and other impurities. There are poor abrasion resistance, complex production process. Titanium industrial production was started in 1948. Require the development of the aviation industry, the titanium industry with an average annual growth rate of about 8% of the development. World titanium alloy production reached 40,000 tons, nearly 30 kinds of titanium alloys. The most widely used titanium alloy is Ti-6Al-4V (TC4), Ti-5Al-2.5Sn (TA7) and commercially pure titanium (TA1, TA2 and TA3).
Titanium is mainly used for the production of aircraft engine compressor components, followed by structure rockets, missiles and high-speed aircraft. The mid-1960s, medical titanium and its alloys have been in general industrial applications, electrodes for electrolysis industry production, power plant condensers, oil refining and desalination heater and environmental pollution control devices. Titanium and its alloys have become a corrosion resistant structural materials. In addition, for the production of hydrogen storage materials and shape memory alloys.
China began in 1956 titanium and titanium alloy study; the mid-1960s and the development of industrial production of titanium into TB2 alloy.

Titanium is a new type of metal, and the performance of the carbon-containing

Titanium is a new type of metal, and the performance of the carbon-containing titanium impurity content of nitrogen, hydrogen, oxygen and so on, the most pure titanium iodide impurity content not exceeding 0.1%, but its low strength, high ductility. 99.5% of the performance of industrial pure titanium plate as: density ρ = 4.5g / cc, a melting point of 1725 ℃, thermal conductivity λ = 15.24W / (mK), the tensile strength σb = 539MPa, elongation δ = 25%, section shrinkage ψ = 25%, the elastic modulus E = 1.078 × 105MPa, the hardness HB195.
High strength
Density of titanium alloys is generally about 4.51g / cc,
Only 60% of steel, titanium density was close to the density of ordinary steel, some high-strength titanium alloy over the strength of the many structural steel. Therefore, the ratio of titanium strength (strength / density) is much larger than other metal structural materials, see Table 7-1, the unit can be made out of high strength, rigidity and lightweight components. Aircraft engine components, skeleton, skin, so the use of titanium fasteners and landing gear.
High heat intensity
Use temperature several hundred degrees higher than aluminum, at moderate temperatures can still maintain the desired strength, long-term work at a temperature of 450 ~ 500 ℃ of these two types of titanium tubing alloys in the range of 150 ℃ ~ 500 ℃ still very high strength, and aluminum at 150 ℃ decreased significantly when compared strength. Titanium alloy operating temperature up to 500 ℃, the aluminum alloy is below 200 ℃.
Good corrosion resistance
Titanium work in humid atmosphere and seawater, which is far superior corrosion resistance of stainless steel; for pitting, etching, stress corrosion resistance is particularly strong; alkali, chloride, chlorine, organic materials, nitric acid, sulfuric acid etc. have excellent corrosion resistance. However, the corrosion resistance of titanium with a reduction of oxygen and chromium salts medium is poor.

Titanium is a new type of metal, and the performance

Titanium is a new type of metal, and the performance of the carbon-containing titanium mesh impurity content of nitrogen, hydrogen, oxygen and so on, the most pure titanium iodide impurity content not exceeding 0.1%, but its low strength, high ductility. 99.5% of the performance of industrial pure titanium as: density ρ = 4.5g / cc, a melting point of 1725 ℃, thermal conductivity λ = 15.24W / (mK), the tensile strength σb = 539MPa, elongation δ = 25%, section shrinkage ψ = 25%, the elastic modulus E = 1.078 × 105MPa, the hardness HB195.
High strength
Titanium can be divided according to use heat-resistant alloys, high-strength alloys, corrosion resistant alloy (Ti - molybdenum, titanium metal supply - palladium alloys, etc.), low alloy and alloy special features. Table typical composition and performance of the alloy.
Titanium heat treatment can be obtained by adjusting the heat treatment process and the organization of different phases. Generally considered fine equiaxed has good ductility, thermal stability and fatigue strength; needle tissue has a high rupture strength, creep strength and fracture toughness; equiaxed and needle hybrid organization has good overall performance.

Titanium is an important structural metal in the 1950s developed

Titanium is an important structural metal in the 1950s developed, titanium rod because of its high strength, corrosion resistance, and high heat resistance and are widely used in various fields. Many countries recognize the importance of titanium alloy materials, have their research and development, and has been applied.
Titanium is the first practical American successfully developed in 1954, because of its heat resistance, strength, ductility, toughness, formability, weldability, corrosion resistance and biocompatibility are good, and become titanium ace alloy alloy industry, which accounts for the use of an alloy of 75% to 85% of all titanium alloys. Many others can be seen as a modification of titanium alloy Ti-6Al-4V alloy.
1950s and 1960s, mainly in the developing high temperature titanium and titanium alloy airframe aviation engine, the 1970s developed a number of corrosion resistant alloys, since the 1980s, corrosion resistant and high-strength titanium screws alloy has been further development of. Temperature resistant titanium alloys 400 ℃ from the 1950s up to the 1990s 600 ~ 650 ℃.
Appears based alloy, the titanium being propelled by the cold end to the hot end of the engine in the direction of the engine using the engine parts. Titanium alloy development to high-strength, high plastic, high strength and high toughness, high modulus and high damage tolerance direction.
In addition, since the 1970s, there was memory alloys, and get increasingly widely used in engineering.

HB350 hardness greater than titanium machining particularly difficult

HB350 hardness greater than titanium machining particularly difficult, less than HB300 is prone to stick a knife phenomenon, but also difficult to cut. However, only one aspect of the hardness of titanium machining difficult, the key is the combined effect of its machinability of chemical, physical and mechanical properties of titanium itself between. Cutting Titanium has the following characteristics:
(1) deformation coefficient is small: This is a significant feature of titanium machining, deformation coefficient is less than or close to one. Chip away the knife sliding friction surface greatly increases the previous accelerated tool wear.
(2) high cutting temperatures: As low thermal conductivity of titanium alloy (equivalent to only 1/5 ~ 1/7 45 steel), the contact length of the chip and the rake is very short, the heat generated when cutting difficult to pass out, concentrated in a smaller range of the cutting area and near the cutting edge, high cutting temperatures. Under the same cutting conditions, the cutting temperature higher than 45 steel cutting more than doubled.

 

All countries in the development of new low-cost and high-performance titanium

All countries in the development of new low-cost and high-performance titanium reducer, titanium alloy into the civilian efforts to make positive industry has huge market potential. New progress of titanium alloy is mainly reflected in the high temperature titanium alloy.
Successfully developed the world's first high-temperature titanium alloy is Ti-6Al-4V, using a temperature of 300-350 ℃. Then have developed a use temperature of 400 ℃ of IMI550, BT3-1 and other alloys, as well as the use of a temperature of 450 ~ 500 ℃ of IMI679, IMI685, Ti-6246, Ti-6242 alloy. Has been successfully applied in military and civil aircraft engines in the new high-temperature titanium alloys have British IMI829, IMI834 alloys; United States of Ti-1100 alloy; Russia BT18Y, BT36 alloy. Table 7 for the highest temperature part of the country's new high-temperature titanium alloy.
In recent years, the use of foreign fast solidification / powder metallurgy technology, fiber or particle-reinforced composites developed high temperature titanium alloy as the development direction, so that the use of temperature titanium alloy can be increased to more than 650 ℃ [1,27,29,31 ]. American McDonnell Douglas by rapid solidification / powder metallurgy technology has successfully developed a high-purity, high-density alloy, its strength at 760 ℃ ambient temperature is equivalent to the intensity of use of titanium

All countries in the development of new low-cost and high-performance titanium

All countries in the development of new low-cost and high-performance titanium, titanium hollow bar into the civilian efforts to make positive industry has huge market potential. New progress of titanium alloy is mainly reflected in the high temperature titanium alloy.
Successfully developed the world's first high-temperature titanium alloy is Ti-6Al-4V, using a temperature of 300-350 ℃. Then have developed a use temperature of 400 ℃ of IMI550, BT3-1 and other alloys, as well as the use of a temperature of 450 ~ 500 ℃ of IMI679, IMI685, Ti-6246, Ti-6242 alloy. Has been successfully applied in military and civil aircraft engines in the new high-temperature titanium alloys have British IMI829, IMI834 alloys; United States of Ti-1100 alloy; Russia BT18Y, BT36 alloy. Table 7 for the highest temperature part of the country's new high-temperature titanium alloy.
In recent years, the use of foreign fast solidification / powder metallurgy technology, fiber or particle-reinforced composites developed high temperature titanium alloy as the development direction, so that the use of temperature titanium alloy can be increased to more than 650 ℃ [1,27,29,31 ]. American McDonnell Douglas by rapid solidification / powder metallurgy technology has successfully developed a high-purity, high-density alloy, its strength at 760 ℃ ambient temperature is equivalent to the intensity of use of titanium

Titanium components used in automobiles

The use of titanium in the car two main categories, the first category is used to reduce the quality of internal combustion reciprocating member (for reciprocating internal combustion engine parts in terms of reducing even a few grams of quality are important); the second category is used to reduce the total mass of the car. According to the design and the material properties of titanium bar on the new generation of vehicles mainly in the engine components and chassis components. In the engine system, can produce titanium valves, valve springs, valve springs and connecting rod bearing and other components; chassis components primarily for springs, exhaust system, axle and fasteners.
According to information, in addition to the above cited focus, there are: Rocker engine parts, suspension springs, piston pin, turbocharger rotor, fasteners, lug nuts, bumper brackets, door broke into the beam, brake caliper piston, the pin bolt, the clutch disc, the pressure plate, the shift button, and so on.

Titanium applications and features in the car

Titanium applications and features in the car
Titanium is a new structural and functional materials, it has excellent overall performance, density, high specific strength. Higher than the strength of the titanium plate alloy aluminum and steel, toughness and steel quite. Titanium and titanium alloy corrosion performance is good, better than stainless steel, particularly resistant to corrosion and micro-oxidizing atmosphere under chloride ion corrosion resistance in the marine atmosphere, a wide operating temperature titanium alloys, titanium alloys at low temperature -253 ℃ but also to maintain good ductility, and heat-resistant alloy operating temperature up to about 550 ℃, its heat resistance was significantly higher than that of aluminum and magnesium alloys. Also has good workability, weldability.
Titanium and titanium alloy Ti excellent performance since the industrial production on various tech industries much attention, along with the titanium bolts industry started in the mid-1950s, titanium into the automotive industry. Into the 1990s, with the worldwide shortage of energy and enhance the awareness of environmental protection, especially in the automotive industry, the US, Japan and Europe and other countries have issued a series of ecological regulations on fuel efficiency, CO2 emissions, vehicle weight, automobile safety, reliability and put forward higher requirements. Many developed countries and the famous car manufacturers are actively developing and increasing investment in automotive research titanium. Provided a powerful impetus for the car with titanium.

Application of titanium in life

Application of titanium in life
Advanced technology and methods of powder metallurgy as a modern metallurgy and materials processing in the titanium sheet industry has played an important role. Titanium powder metallurgy nearly molding technology, direct preparation of finished or nearly finished size of components, reducing the consumption of raw materials, shorten the processing cycle, cost savings of 20% to 50% compared with conventional processes. In the automotive industry, titanium powder metallurgy particular attention in recent molding technology in Japan, powder metallurgy parts are widely used in automobile engines and transmissions, which, connecting rods, valve seats, valve, the pulley, the synchronizer hub, synchronizing rings so are complex and demanding critical parts. Zhu titanium powder metallurgy current research is in the stage of rapid development, including a child, first, high-quality low-cost titanium powders were prepared by technology and its industrialization; the second is the preparation of titanium plate powder metallurgy technology even while in the automotive industry promotion applications.

One reason for the high price of titanium alloying elements is higher prices.

One reason for the high price of titanium alloying elements is higher prices.
With the progress of titanium smelting technology, the rear titanium investment casting production process generated Scrap, scrap and other salvage treatment after the series as the charge added to achieve the production cycle, is an effective way to reduce the cost of raw materials. Practice shows that for every 1% of residual use of titanium, titanium ingot can reduce production costs by 0.8%. If the electron beam cooling bed furnace, plasma beam cooling bed furnace smelting, can not only improve the quality of titanium ingot metallurgy, while extensive use of recycled scrap, ingot reduce costs.
Reduce processing costs
More than 60% of the total cost of processing costs for countries to reduce the cost of key research. titanium tubing components in the production process of the production process is not only complex, but generated a lot of residual titanium in the production process, and a longer production cycle, resulting in parts production costs. Hinders its broader application.
Casting is a classic (nearly) net molding process. Production of parts without machining or machining rarely, thus saving a lot of metal. Casting can often produce a complex shape parts, and these parts are made of other conventional process for the manufacture of complex, high production costs, especially for the relatively high price of materials titanium. Currently, a large number of applications in the aerospace industry titanium castings. In the automotive industry, the production of parts by casting method has a valve, turbo pressure, etc. zo.