High-formability unsaturated titanium hydride powder and preparation method thereof

Abstract

The invention belongs to the field of titanium alloy powder metallurgy materials and provides high-formability unsaturated titanium hydride powder. The high-formability unsaturated titanium hydride powder comprises 70wt%-77wt% of a main phase TiH1.5, 13wt%-18wt% of an alpha-Ti phase and 10wt%-15wt% of a TiH phase and is prepared by unsaturated hydrogen absorption of titanium sponge or incomplete dehydrogenation of TiH2 powder. The unsaturated titanium hydride powder is excellent in formability, less prone to cracking and layering in blank forming, high in forming rate and especially suitable for manufacturing of complex large parts and has advantages of high sintering yield in subsequent sintering and excellent product mechanical properties.

Description

technical field [0001] The invention belongs to the field of titanium alloy powder metallurgy materials, and relates to a highly formable unsaturated titanium hydride powder and a preparation method thereof. Background technique [0002] For the production of titanium and titanium alloy products, powder metallurgy can obtain products with uniform composition, incompatible liquid phases, high melting point, semi-dense or fully dense, and near-formed products, which are more advantageous than traditional casting and forging methods. However, the traditional powder metallurgy method uses titanium powder and alloy powder as raw materials, and the obtained titanium or titanium alloy products have low density and high oxygen content. Generally, subsequent thermal processing is required to obtain products with higher density. , and the subsequent thermal processing will not only increase the production cost, but also the operation steps are cumbersome, which is not conducive to the...

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Problems solved by technology

However, the traditional powder metallurgy method uses titanium powder and alloy powder as raw materials, and the obtained titanium or titanium alloy products have low density and high oxygen content. Generally, subsequent thermal processing is required to obtain products with higher density. , and the follow-up thermal processing will not only increase the production cost, but also the operation steps are cumbersome, which is not conducive to the improvement of production efficiency

[0003] At present, there are reports in the literature that directly use saturated titanium hydride (TiH 2 ) powder and alloy powder, through compression molding, the formed body is sintered at high temperature under vacuum or inert gas protection atmosphere, and titanium or titanium alloy products with high density can be obtained, but due to the high brittleness and high hardness of saturated titanium hydride , in the process of pressing and forming, the green body is prone to cracking and delamination, the forming rate is low, and its poor formability makes TiH 2 The molding rate of powder is very low when making more complex and large parts, which greatly limits the scope of application of this method

At the same time, during the sintering process, due to the removal of more hydrogen, the volume shrinkage is relatively large, and it is also very easy to cause cracks in titanium or titanium alloy products, resulting in a decrease in the yield of sintering

In addition, due to the need to remove a large amount of hydrogen during the sintering process, it is necessary to increase the sintering time, and the increase in the sintering time will not only increase the cost, but also cause the microstructure and grain of the alloy to become larger, resulting in poor mechanical properties of the product

[0004] Based on the above technical status, if a powder with better formability can be developed to effectively avoid the use of TiH 2 Powders and their alloy powders are prone to cracking and delamination when producing titanium products by powder metallurgy, low molding rate, and low sintering yield. They are not suitable for complex and large-scale parts and poor mechanical properties of products. , will have important significance for the field of powder metallurgy production of titanium and titanium alloy products

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