Preparation method for near-eutectic Nb-Si-Mo alloy with feature of oriented arrangement of lamellar tissues

Abstract

The invention belongs to the technical field of preparation of high-temperature structural materials, and relates to a preparation method for a near-eutectic Nb-Si-Mo alloy with orientated-arranged lamellar tissues. The preparation method is characterized in that a powder feeding type laser rapid forming technology is adopted to prepare the near-eutectic Nb-Si-Mo alloy with the fine layer sheet-shaped orientated-arranged lamellar tissues, commercially available pure element powder is adopted as a raw material, spherical powder or pre-alloyed powder does not need to prepare especially, and thepreparation process for the raw material is simple; and the alloy is composed of Nb solid solution phases and beta-Nb5Si3 phases, the lamellar Nb solid solution phases with the size of about 100-500 nm and the lamellar beta-Nb5Si3 phases are alternately arranged, and all the lamellar Nb solid solution phases and the lamellar beta-Nb5Si3 phases are approximately arranged in the same direction. Compared with a Nb-Si-Mo eutectic alloy prepared by a traditional directional solidification process, a traditional trmagnetron sputtering process and the like, the preparation method for the near-eutectic Nb-Si-Mo alloy with the orientated-arranged lamellar tissues has the advantages that based on laser rapid melting and solidification characteristics, the more fine lamellar tissues can be obtained,and full-eutectic crystallization of microscopic tissues of the Nb-Si-Mo alloy of near-eutectic composition can be realized.

Description

technical field [0001] The invention belongs to the technical field of preparation of high-temperature structural materials, and relates to a method for preparing a near-eutectic Nb-Si-Mo alloy with lamellar structure orientation arrangement characteristics. Background technique [0002] In order to meet the development needs of high thrust ratio aeroengine blades, research on new ultra-high temperature structural materials with a temperature bearing capacity exceeding 1200 °C is one of the current research hotspots in the field of materials. As a next-generation high-temperature structural material, Nb-Si-based alloys show attractive application prospects and have attracted widespread attention. They are considered to be the most promising new-generation ultra-high-temperature structural materials that can replace the existing nickel-based superalloys in the short term. [0003] Processes and alloying elements will have a significant impact on the microstructure of Nb-Si-ba...

AI Technical Summary

Problems solved by technology

The preparation of layered gold by physical vapor deposition requires alternate deposition of Nb and Si. The preparation process is complicated and the structure is very coarse. The thickness of a single layer of Nb or Nb5Si3 is about 0.1-0.5mm. In addition, there may be some metastable phases in the alloy. , which affects the stability of the material structure, requires subsequent treatment to completely eliminate