Cast titanium alloy material suitable for high temperature of 650-750 DEG C and preparation method thereof

Abstract

The invention relates to a cast titanium alloy material suitable for the high temperature of 650-750 DEG C and a preparation method thereof. The cast titanium alloy material is prepared from the alloycomponents in specific chemical percentage by mass: 5.0-7.5% of Al, 3.0-5.5% of Zr, 0.5-3.0% of Nb, 0.2-2.0% of Mo, 0.1-0.6% of Si, less than or equal to 0.15% of O, and the balance of Ti and unavoidable impurity elements. During preparation, raw materials are selected from ultra 0A grade-0A grade small particle titanium sponge, and the alloy elements Nb, Mo and Si are added in the form of intermediate alloys; Zr is added in the form of zirconium sponge; a part of Al is brought in by the intermediate alloys, and the insufficient part is added by pure aluminum; the intermediate alloys and thetitanium sponge are compounded, mixed, and then compressed into electrodes; the electrodes are assembled, welded and then made into an alloy ingot by smelting, then the alloy ingot is cast into an alloy casting, and after heat isostatic pressure treatment, internal shrinkage holes are removed to produce a finished product. The cast titanium alloy material has the good room temperature and the high-temperature mechanical performance of 650-750 DEG C, the high-temperature creep performance of 650-750 DEG C and the endurance performance can also meet the design requirements, the good casting andwelding properties are achieved, and the using requirements of key structural parts of airspace engines are met.

Description

technical field [0001] The invention belongs to the technical field of titanium alloy materials, and relates to a casting titanium alloy material suitable for high temperature of 650-750 DEG C and a preparation method thereof. Background technique [0002] With the continuous development of aerospace technology, hypersonic vehicles have become the mainstream direction for countries all over the world to enhance their military competitiveness. As the core component of hypersonic aircraft, aeroengines require service materials to have good room temperature and high temperature mechanical properties, high temperature durable creep properties, thermal stability, fatigue properties, and fracture toughness. And the performance improvement of the engine largely depends on the improvement of the high temperature performance of the materials used. In this context, countries around the world have developed a variety of high-temperature titanium alloy materials suitable for 600 °C. Ty...

AI Technical Summary

Problems solved by technology

However, it is still unable to meet the urgent needs of aerospace engines for high-temperature titanium alloys at 650-750 °C

[0003] At present, the typical representative of titanium alloys used at 700 °C is Ti 3 Al-based intermetallic compounds, which are characterized by high specific strength, high specific modulus and resistance to combustion, but low room temperature plasticity and fracture toughness

The thermal stability of titanium alloys between 600-700 °C mainly involves the brittle phase Ti 3 The precipitation of X (X=Al, Ge, In, Sn, etc.), and the usual method of optimizing the alloy content to increase the alloy’s service temperature may cause the brittle phase of Ti 3 X precipitation, thereby reducing the thermal stability of the alloy

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