• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2021, Vol. 57 ›› Issue (6): 96-105.doi: 10.3901/JME.2021.06.096

• 材料科学与工程 • 上一篇    下一篇

扫码分享

不同成分下铸态 AlMoNbTaTiZr 高熵合金显微组织的研究

于秋颖, 贺晓勇, 谢孝昌, 方爽, 李能, 黄帅, 熊华平   

  1. 中国航发北京航空材料研究院焊接与塑性成形研究所 北京 100095
  • 收稿日期:2020-12-21 修回日期:2021-01-28 出版日期:2021-03-20 发布日期:2021-05-25
  • 通讯作者: 熊华平(通信作者),男,1969年出生,博士,教授,博士研究生导师。主要研究方向为焊接、增材制造及高熵合金等。E-mail:xionghuaping69@sina.cn
  • 作者简介:于秋颖,女,1984年出生,博士,高级工程师。主要研究方向为高温合金及高熵合金研究与热变形组织控制。E-mail:qiuyingyu@126.com
  • 基金资助:
    国家自然科学基金资助项目(51775525,51901218,52005465)。

Effects of the Variation of Alloy Composition on Microstructures of As-cast AlMoNbTaTiZr High-entropy Alloys

YU Qiuying, HE Xiaoyong, XIE Xiaochang, FANG Shuang, LI Neng, HUANG Shuai, XIONG Huaping   

  1. Laboratory of Welding and Plastic Forming, AECC Beijing Institute of Aeronautical Materials, Beijing 100095
  • Received:2020-12-21 Revised:2021-01-28 Online:2021-03-20 Published:2021-05-25

摘要: 通过非自耗真空电弧熔炼法制备AlaMobNbcTadTiZr(a=1.5, 0.5, 0.25; b=0.5, 0.25, 0; c=0.5, 0; d=0.5, 0.75, 1)高熵合金,研究合金元素含量、热力学参数、显微组织间的关系。结果表明,除了Al1.5Mo0.5NbTa0.5TiZr合金由BCC相和富Al-Zr相组成外,其他AlaMobNbcTadTiZr合金由单相BCC固溶体相组成。铸态合金呈现典型的枝晶形貌,Al、Zr和Ti偏析于枝晶间,Mo、Ta和Nb偏析于枝晶干,合金成分变化对凝固过程元素分布的影响较小,但Al比Zr对富Al-Zr相析出的影响更为显著。在a,b,c和d数值减小的AlaMobNbcTadTiZr中,富Al-Zr相析出被抑制,枝晶组织逐渐粗化。Al1.5Mo0.5NbTa0.5TiZr合金因富Al-Zr相的析出使得显微硬度最高,可达650.0 HV0.3,Al0.25NbTa0.5TiZr合金的最低可达407.6HV0.3。

关键词: AlMoNbTaTiZr难熔高熵合金, 铸态, 相形成规律, 显微组织

Abstract: AlaMobNbcTadTiZr (a=1.5, 0.5, 0.25; b=0.5, 0.25, 0; c=0.5, 0; d=0.5, 0.75, 1) high-entropy alloys were prepared by a non-consumable vacuum arc melting. The relations of the content of alloying elements, thermodynamic parameters, microstructure evolution were studied. The results show that other AlaMobNbcTadTiZr alloys are composed of single-phase BCC solid solution phase except Al1.5Mo0.5NbTa0.5TiZr alloy composed of BCC phase and Al-Zr rich precipitate. The as-cast AlaMobNbcTadTiZr high entropy alloy has a typical dendritic microstructure. The elements of Al, Zr and Ti, and the elements of Mo, Ta and Nb are segregated in the interdendritic and dendritic core regions, respectively. The distribution of elements during solidification is scarcely affected by the variation of alloy composition. However, the precipitation of Al-Zr rich precipitate is more significantly affected by Al than Zr. The inhibition of Al-Zr rich precipitate occurs and a solid solution with coarser dendrites is formed in the AlaMobNbcTadTiZr high-entropy alloys with the reduction of a, b, c and d. Al1.5Mo0.5NbTa0.5TiZr alloy shows the highest micorhardness with the value of 650.0HV0.3 due to the precipitation of Al-Zr rich phase, and Al0.25NbTa0.5TiZr alloy shows the lowest micorhardness with the value of 407.6HV0.3.

Key words: AlMoNbTaTiZr refractory high-entropy alloy, as cast, phase formation criterion, microstructure

中图分类号: