Because the small and medium gas turbine is widely used as the ship power plant, the weight of the unit is higher. Therefore, compressor blades, wheel and other key parts are largely made of
titanium alloy. At present, small and medium-sized gas turbine compressor used titanium alloy TC4 (foreign brand:
Ti-6Al-4V), TC11 (foreign brand: BT9), TA19 (foreign brand:
Ti6242) and so on.
TC4 (Ti-6Al-4V) titanium alloy, which contains 6% α-stable element Al and 4% β-stable element V, is a Ti-Al-V α-β type titanium alloy which was successfully developed by the United States in 1954. The main characteristics of TC4 titanium alloy are excellent comprehensive properties and good process characteristics, the service temperature is 350 ℃. The alloy is widely used, and its output is almost half of the total output of titanium alloy.
TC11 titanium alloy is a kind of α-β titanium alloy with good comprehensive properties. It has excellent thermal strength under 500 ℃ and high strength at room temperature. The alloy also has good thermal processing properties (including conventional process properties and superplasticity), and can be welded and machined in various ways. At present, with the continuous expansion of application of TCL1 titanium alloy, the β-heat treatment and isothermal forging of the alloy have been developed rapidly.
TA19 is a nearly α-type titanium alloy with nominal composition of
Ti-6Al-2Sn-4Zr-2Mo, containing α-stable elements Aluminium, neutral elements stannum and
zirconium, isomorphic β-stable element
molybdenum, eutectoid β-stable element silicon. Molybdenum can increase the tensile strength at room temperature and high temperature and enhance the stability. The composite action of Al, Sn and Zr can keep the high temperature strength of long time and creep. Adding Si can precipitate the dispersion phase of silicide, which is beneficial to improve the creep strength at high temperature. The alloy also has high strength at 540 ℃, with a maximum long-term service of 500 ℃.
