摘要
TiAl基合金是一种在航空航天等领域极具应用前景的轻质高温结构材料,通过控制TiAl基合金中片层取向可显著提升合金在单向受力条件下的综合力学性能。本文介绍了籽晶法定向凝固技术在TiAl基合金片层取向控制的最新进展,回顾了传统Ti-43Al-3Si籽晶法所面临的问题,重点总结了近年来新发展的二次定向凝固法、原位自籽晶定向凝固法、准籽晶定向凝固技术以及高熔点金属籽晶定向凝固技术,这些技术有利于促进籽晶法定向凝固控制TiAl基合金片层取向的工程化进展。但TiAl基合金中不同相的实际生长取向的持续稳定需要籽晶引晶与动力学条件的相结合才能得以实现,因此,新型籽晶技术与定向凝固工艺条件的互相结合将是未来籽晶法的发展趋势。
TiAl-based alloys will be potentially used as light-weight high temperature structural materials in aerospace industry. The comprehensive mechanical properties of TiAl-based alloys can be improved significantly when lamellar orientation is aligned parallel to principle stress. In this paper, the development of seeding technique in directionally solidified TiAl-based alloys is reviewed, including the traditional Ti-43 Al-3 Si seeding method and some novel seeding methods. Those methods mainly include the second directional solidification method, self-seeding technique, quasi-seeding technique and highmelting metal seeding technique. Those newly developed methods will promote the engineering applications of the lamellar structure controlling technology for TiAl-based alloys. However, the stable growth of different leading phase in its designed direction depends on the coupling of the seed and growth dynamic parameteres. How to discover the influence of the growth dynamic parameteres on the designed growth direction is a key problem.
作者
苏彦庆
刘桐
李新中
陈瑞润
郭景杰
傅恒志
SU Yanqing;LIU Tong;LI Xinzhong;CHEN Ruirun;GUO Jingjie;FU Hengzhi(National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第5期647-656,共10页
Acta Metallurgica Sinica
基金
国家自然科学基金项目Nos.51425402和51331005
国家重点研发计划项目No.2017YFA0403804
长江学者奖励计划项目No.T2014227~~
关键词
TIAL基合金
定向凝固
籽晶法
片层取向控制
TiAI-based alloy
directional solidification
seeding technique
lamellar orientation controlling
