Titanium alloy has good comprehensive performance, is an excellent structural material, and is widely used.
However, the cost performance of titanium alloy is relatively low, the parts are not easy to machine, and the cost is high. Through casting methods, especially precision casting, parts with complex shapes can be directly manufactured, eliminating a large number of machining processes, and increasing the utilization rate of materials to nearly 90%.
Cast titanium alloys are usually divided into a, a + B, and β alloys according to phase composition, and are also divided into cast high-strength, heat-resistant, and corrosion-resistant titanium alloys by convention. Among them, casting Ti-6Ai-4V and T5Ai-2.5Sn are widely used casting titanium alloys, which are characterized by moderate strength, heat resistance, corrosion resistance, and good plasticity, which are particularly suitable for aerospace engines and structural castings. .
The cast Ti6242 alloy (Ti-6Ai-2sn-4Zr-2Mo) developed in the United States can work below 500 ° C and can be used in compressor parts for aero engines, accounting for more than 2% of the amount of cast titanium alloy. China’s ZTC6 is a near-alpha titanium alloy developed with reference to the Ti6242 alloy. The aluminum content of the alloy is controlled below 8%, and the high temperature thermal stability is good. It has been applied to engine components below 500 ° C. ZTC3 (Ti-Al-Mo-Si system) can also be used for a long time below 500 ℃, due to the addition of rare earth element Ce, the alloy has good heat resistance.
The cast Ti153 alloy (Ti-15V-3Al-3Cr-3Sn) is a metastable B-type high-strength titanium alloy. The alloy can be solid solution and aging strengthened. The strength of the alloy can reach more than 1200MPa, and the alloy has an extension of more than 5% Long rate. ZTC5 alloy is a high-strength titanium alloy developed by China. It is an a + type cast titanium gold developed on the basis of Ti-Al-Mo-Sn-Zr heat-resistant titanium alloy. Through the addition of rapid eutectoid elements, it has improved The strength of the alloy during aging, not only high strength and toughness, but also used below 350 ℃, has good thermal stability.
