High-temperature-resistant aluminum titanium oxide alloy and preparation method thereof

Abstract

The invention relates to a preparation method of high-temperature-resistant beta-gamma aluminum titanium oxide alloy and belongs to the field of high-temperature alloys. The beta-gamma aluminum titanium oxide alloy comprises the following components: 40.0-44.0at% of Al, 3.0-5.0at% of Nb, 0.5-1.5at% of Mo, 0.1-0.5at% of Si, 0.1-0.3at% of B and the balance of Ti and inevitable impurity elements. The preparation method comprises the following step of repeatedly smelting titanium sponge, high-purity aluminum, a TiNb alloy, a TiMo alloy, pure Si and pure B powder as raw materials in a vacuum suspension furnace or a nonconsumable vacuum electrical arc furnace. The alloy has the advantages of good oxidation resistance and thermal processing performance, can be used at 800 DEG C in a long term without surface treatment and can be suitable for being processed into aerospace and automotive engine parts which work at about 800 DEG C.

Description

technical field [0001] The invention belongs to the field of high-temperature alloys, in particular to a high-temperature oxidation-resistant titanium-aluminum alloy and its preparation method Background technique [0002] With the rapid development of the globalization of modern science and technology, the competition between global regions presents a trend of multipleization and complexity. The development process of the aerospace industry in national defense science and technology is still an important criterion for measuring a country's technological level and comprehensive national strength. Among them, the development level of aircraft engines is an important foundation of the aviation industry; research and development can save fuel, reduce the weight of the engine, and at the same time improve the working efficiency and driving force of the engine, which has become an important goal for material researchers in various countries in the research direction of high-temper...

AI Technical Summary

Problems solved by technology

[0004] Although TiAl alloys have good prospects in the application of aero-engines, their low fracture toughness, low plasticity and poor high-temperature oxidation resistance are the main bottlenecks that limit their use.

The current TiAl alloy is used at a temperature of 680-750°C, and when the operating temperature exceeds 750°C, the oxidation resistance decreases significantly, which greatly limits its application range in the aviation industry.

High temperature use is limited by poor high temperature oxidation resistance

On the one hand, the formation of oxidation products reduces the load-bearing cross-sectional area of ​​the part and ultimately limits the time that the integrity can be maintained at the service temperature

On the other hand, during high-temperature heat exposure, high-concentration oxygen dissolves into the surface of the alloy to form a broken oxygen-rich layer, which greatly reduces the plasticity of the alloy.

[0005] At present, academician Chen Guodong of the State Key Laboratory of New Materials and others have found that high Nb-TiAl alloys can significantly improve their oxidation resistance, but if the Nb content is too high, TiNb will form in the oxide film. 2 o 7 , AlNbO 4 Phase or Nb 2 o 5 , unfavorable to alloy oxidation, and easy to segregate during pouring

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