Titanium and titanium anode have good welding, cold and hot pressure processing and mechanical processing properties, can be processed into various profiles, plates and pipe supply.
Titanium is an ideal structural material, the density of titanium is not very large, only 4.5g/m3, 43% lighter than steel, but the strength of titanium is twice higher than that of iron, almost 5 times higher than that of pure aluminum. It has low density and high strength. This combination of high strength and low density makes titanium play a very important role in technology. At the same time, titanium has been widely used in petroleum, chemical industry, pesticide, dye, paper making, light industry, aviation, cosmology development, marine engineering and so on.
Titanium alloy has a high specific strength (ratio of strength and density), and titanium alloy has played an irreplaceable role in aviation, military industry, shipbuilding, chemical industry, metallurgy, machinery, medical and other fields. For example, the strength limit of titanium alloy with aluminum, chromium, vanadium, molybdenum, manganese and other elements can reach 1176.8-1471mpa and specific strength of 27-33 after heat treatment. For alloy steel with the same strength, its specific strength is only 15.5-19. Titanium alloy is not only high strength but also corrosion resistant, so it has been widely used in ship manufacturing, chemical machinery and medical equipment. Among them, corrosion-resistant titanium alloy is mainly used in reactor, tower, autoclave, heat exchanger, pump, valve, centrifuge, pipe, pipe, electrolytic cell and so on. However, the high price of titanium and its alloys limits their application.
application of common titanium and titanium alloy:
1) iodine titanium, brand Tad
is a high purity titanium obtained by iodization, so it is called iodine titanium, or chemical titanium. However, there are still some impurity elements such as oxygen, nitrogen and carbon, which have a great influence on the mechanical properties of pure titanium. With the increase of purity of titanium, the strength and hardness of titanium decreased obviously, so its characteristics are: good chemical stability, but low strength.
Because of its low strength, it is not very important to be used as structural material, so it is rarely used in industry. At present, titanium and titanium alloy are widely used in industry.
The difference between Ti and chemical pure titanium is that industrial pure titanium contains a lot of oxygen, nitrogen, carbon and other impurity elements (such as iron and silicon), which is a kind of titanium alloy with low alloy content in essence. Compared with pure titanium, because of the more impurity elements, its strength is greatly improved, and its mechanical and chemical properties are similar to stainless steel (but the strength is still lower than that of titanium alloy).
the characteristics of industrial pure titanium are: low strength, but good plasticity, easy to process, stamping, welding and machinability; good corrosion resistance in atmosphere, sea water, wet chlorine gas and oxidizing, neutral and weak reducing medium, and better oxidation resistance than most austenitic stainless steel; however, the heat resistance is poor and the temperature should not be too high.
According to the different impurity content, industrial pure titanium can be divided into three grades: TA1, TA2 and TA3. The gap impurities of these three industrial pure titanium are gradually increased, so the mechanical strength and hardness of these three kinds of titanium are gradually increased, but the plasticity and toughness decrease accordingly.
The industrial pure titanium commonly used in industry is TA2, because of its moderate corrosion resistance and comprehensive mechanical properties. TA3 can be used when the wear resistance and strength requirements are high. TA1 can be used for the forming performance with good requirements.
industrial pure titanium is mainly used for stamping parts and corrosion-resistant structural parts with good plasticity, such as aircraft frame, skin and engine accessories, marine pipeline, valve, pump, hydrofoil and desalination system parts; heat exchanger, pump body, distillation tower, cooler, agitator and tee in chemical industry Impeller, fastener, ion pump, compressor valve and diesel engine piston, connecting rod, leaf spring, etc.
α type titanium alloy, grade TA4, TA5, TA6, TA7.
the alloy is in A-phase state at room temperature and service temperature, and cannot be heat treated (annealing is the only heat treatment form), which mainly depends on solid solution strengthening. The strength of room temperature is lower than that of β and α + β titanium alloy (but higher than that of industrial pure titanium), while the strength and creep strength at high temperature (500-600 ℃) are the highest among the three kinds of titanium alloys. The structure stability, oxidation resistance and welding performance are good, corrosion resistance and machinability are also good, but the plasticity is low (thermoplastic is still good), and the stamping performance at room temperature is poor. TA7 is widely used, which has medium high strength and sufficient plasticity under annealing condition, and has good weldability, and can be used below 500 ℃; when the content of impurity elements (oxygen, hydrogen, nitrogen, etc.) is very low, it also has good toughness and comprehensive mechanical properties at ultra-low temperature, and is one of the excellent ultra-low temperature alloys.
The tensile strength of TA4 is slightly higher than that of industrial pure titanium, and can be used as structural materials with medium strength range. Domestic mainly used as welding wire.
TA5 and TA6 are used for parts and welding parts working in corrosive medium under 400 ℃, such as aircraft skin, skeleton parts, compressor casing, blades, ship parts, etc.
TA7 is used for structural parts and various mold forging parts working under 500 ℃ for a long time, and can be used to 900 ℃ in a short time. It can also be used for ultra-low temperature (-253 ℃) components (such as containers for ultra-low temperature).
β (4) titanium alloy, brand TB2.
the main alloy elements of this kind of alloy are stable elements of molybdenum, chromium, vanadium and other β phases. It is easy to keep high temperature β phase to room temperature during normalizing and quenching, so it is easy to obtain stable β phase structure, so it is called β type titanium alloy.
The Ti alloy can be heat treated and strengthened with high strength, good welding performance and pressure processing performance. However, the performance is not stable enough and the smelting process is complex, so it is not widely used as type A and α + β titanium alloy.
it can be used for parts working under 350 ℃, mainly used for manufacturing sheet stamping parts and welding parts of various overall heat treatment (solid solution and aging); such as compressor blades, wheel discs, shafts and other heavy load rotating parts and aircraft components. TB2 alloy is generally delivered in the state of solid solution treatment, and is used after solution and aging.
The common brands TC6, TC9 and TC10 of (5) α + β titanium bars and titanium alloys
The alloy is named as α + β titanium alloy because it has a two-phase structure of α + β type at room temperature. It has good comprehensive mechanical properties, most of which can be heat treated (but Tc1, TC2 and TC7 cannot be heat treated), forging, stamping and welding are all good, and it can be machined and high in room temperature strength. It has high heat resistance under 150-500 ℃, some (such as Tc1, TC2, TC3, TC4) also have good low temperature toughness, good resistance to sea stress corrosion and heat salt stress Corrosion capacity; the disadvantage is that the structure is not stable.
The TC4 is the most widely used alloy, and the amount of TC4 accounts for about half of the production of titanium alloy. The alloy has not only good mechanical properties at room temperature, high temperature and low temperature, but also has excellent corrosion resistance in a variety of media, and can be welded, cold and hot formed, and can be strengthened by heat treatment. Therefore, it has been widely used in aerospace, ship, chemical industry and other industries.
Tc1 and TC2 can be used for stamping parts, welding parts, die forgings and various parts of bending process under 400 ℃. The two alloys can also be used as low temperature structural materials.
TC3 and TC4 can be used as parts for long-term work under 400 ℃, structural modules, various containers, pumps, low temperature components, ship pressure shell, tank track, etc. The strength is higher than Tc1 and TC2.
TC6 can be used below 400 ℃ and is mainly used as structural material of aircraft engine. TC9 can be used to manufacture parts that work for a long time under 560 ℃, mainly used on the compressor disk and blade of the jet engine.
TC10 can be used to manufacture parts that work for a long time under 450 ℃, such as aircraft structural parts, landing gear, cellular connecting members, missile engine shell, weapon structure, etc.