A kind of high temperature and high strength titanium alloy and its additive preparation method

Abstract

The invention discloses a high-temperature and high-strength titanium alloy and an additive preparation method thereof. The high-strength titanium alloy of the present invention comprises, in terms of mass percentage, 80-88% Ti; 8%-14.5% Al; 2.8-3.8% Mo; 0.8- 2.0%Zr; 0.2-0.5%Si; 1.2-1.3%Mn; 0.7-1%Zn; 0.1-0.3%Cu. The high-strength titanium alloy of the present invention adopts a high-energy beam additive manufacturing method for directional deposition, designs a titanium alloy suitable for additive manufacturing based on the specific composition of TC11, and utilizes the characteristics of additive manufacturing of small molten pools and high cooling rates to reduce elements The segregation of the alloy makes the distribution of alloy elements uniform, which significantly improves the high-temperature mechanical properties of the titanium alloy.

Description

technical field [0001] The invention relates to a method for manufacturing a titanium alloy by laser additive, in particular to a high-strength titanium alloy and a method for preparing the additive. Background technique [0002] Titanium alloys have been widely used in aerospace, ships, automobiles, chemicals, medical equipment and sporting goods. As far as the operating temperature of titanium alloys is concerned, the current maximum working temperature of titanium alloys has been increased from the initial 350 °C to 650 °C. [0003] TC11 titanium alloy is an α+β type titanium alloy, the specific composition is Ti-6.5Al-3.5Mo-1.5Zr-0.3Si. TC11 titanium alloy has high specific strength, good thermal processing performance, strong corrosion resistance, low thermal expansion coefficient and low thermal conductivity, and can be used for a long time at 500 ℃. However, with the continuous improvement of aero-engine thrust-to-weight ratio and vortex front temperature, the worki...

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Problems solved by technology

However, with the continuous improvement of the thrust-to-weight ratio and the temperature before the vortex of the aero-engine, the working conditions of the engine parts become more complex and harsh, and the temperature is getting higher and higher. Therefore, the TC11 titanium alloy is facing serious damage during use. High temperature oxidation and other issues

[0004] Although a higher aluminum content can improve the high-temperature strength and other properties of titanium alloys to a certain extent, excessive aluminum content is prone to segregation and other problems during the forming process of the alloy, resulting in internal structural defects, which become a problem during high-temperature use. The initial parts such as cracks and oxidation cause the overall failure of the parts, and at the same time, the alloy is extremely prone to cracking during forging, resulting in low yield

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