Casting a, a + B and β titanium alloy classification and its properties, grades, chemical composition

Titanium alloy has good overall performance, is an excellent structural material, widely used. However, the cost-effectiveness of titanium alloy is relatively low, the parts are not easy to machining, high cost. Through the casting method, especially precision casting can directly manufacture complex shaped parts, eliminating a large number of machining processes, so that the utilization rate of the material is increased to close to 90%.

Cast titanium alloys are usually divided into a, a + B and β alloys according to the phase composition, according to the custom is also divided into cast high-strength, heat-resistant and corrosion-resistant titanium alloys. Among them cast Ti-6Ai-4V and T5Ai-2.5Sn is more widely used cast titanium alloys, which is characterized by medium strength and heat resistance, corrosion resistance, as well as good plasticity, especially suitable for aerospace engines and structural castings. The United States developed casting Ti6242 alloy (Ti-6Ai-2sn-4Zr-2Mo) can work at 500 ℃, can be used for aerospace engine compressor parts, accounting for about casting titanium alloy dosage of more than 2%. China's ZTC6 is based on Ti6242 alloy development of a near-alpha type titanium alloy, the alloy's aluminum content is controlled at 8% or less, high-temperature thermal stability is good, has been applied to the engine parts below 500 ℃. ZTC3 (Ti-Al-Mo-Si system) can also be used for a long time below 500 ℃, due to the addition of the rare earth element Ce, the alloy has a very good heat-resistant properties. Casting Ti153 alloy (Ti-15V-3Al-3Cr-3Sn) belongs to the sub-stable B-type high-strength titanium alloy, the alloy can be solid solution and aging strengthened, the alloy's strength can reach more than 1,200MPa, and the alloy has more than 5% elongation. ZTC5 alloy is a self-developed high-strength titanium alloy, which is a heat-resistant titanium alloy based on the Ti- Al-Mo-Sn-Zr system. It is a kind of a+ type casting titanium alloy developed on the basis of Ti-Al-Mo-Sn-Zr system heat-resistant titanium alloy, through the addition of fast eutectic elements, improve the strength of the alloy during aging, the alloy is not only high-strength and high-toughness, but also in the use of the following 350 ℃, has a very good thermal stability.