Preparation method of Nb-Si-Ti alloy with directional solidification structure

Abstract

The invention belongs to the technical field of preparation of high-temperature structural materials, and relates to a powder feeding type laser rapid forming technology, in particular to a preparation method of a Nb-Si-Ti alloy with a directional solidification structure. The Nb-Si-Ti ternary alloy with fine directional solidification structure characteristics is prepared by adopting the powder feeding type laser rapid forming technology, commercially available pure element powder is used as a raw material, spherical powder or pre-alloyed powder does not need to be prepared particularly, andthe preparation process of the raw material is simple; the Nb-Si-Ti alloy with an eutectic component or a sub-eutectic component is adopted, and the influence of primary silicide relative to the directional solidification structure continuity is avoided; after the deposited alloy is cooled to below 100 DEG C, a next deposition layer is prepared, a directional solidification alloy is adopted as a forming substrate, a directional hot flow can be formed in the powder feeding type laser rapid forming process, and the structure stability of the Nb-Si-Ti alloy is ensured; and through point-by-pointmelting and solidification of the powder, the problems of unavoidable component segregation in the traditional casting Nb-Si process, the uniform structure and coarse grain are eliminated.

Description

technical field [0001] The invention belongs to the technical field of preparation of high-temperature structural materials, and relates to a powder-feeding laser rapid prototyping technology, in particular to a method for preparing a Nb-Si-Ti alloy with a directional solidification structure. Background technique [0002] The Nb-Si alloy is toughened by Nb-based solid solution (NbSS) at room temperature and enhanced by silicide at high temperature. However, the requirements of its strength and toughness indicators on the structure are contradictory, which makes the comprehensive performance matching and regulation of the alloy extremely challenging. According to existing studies, directional solidification can simultaneously improve the room temperature fracture toughness and high temperature strength of Nb-Si based superalloys. SS / Nb 5 Si 3 The room temperature toughness of multi-component Nb-16Si-24Ti-8Hf-2Al-2Cr alloy can reach up to 23MPa m 1 / 2 , The strength at 120...

AI Technical Summary

Problems solved by technology

[0004] In addition, the Nb-Si-based alloys prepared by the above-mentioned directional solidification methods are relatively coarse, and the mechanical properties are difficult to guarantee, and it is difficult to directly prepare alloy parts with specific dimensions, complex shapes, and structures (variable cross-sections, inner cavities, or cooling channels).