(1. 哈尔滨工业大学 金属精密热加工国防科技重点实验室，
哈尔滨 150001；
2. 西北工业大学 凝固技术国家重点实验室， 西安 710072)
摘 要: 在航空航天及能源领域有重要应用价值的TiAl基合金， 由于其γ+α2片层结构的特点， 采用定向凝固技术控制片层方向可以更好地发挥其潜能。 从相与组织选择及晶体择优生长特性角度， 讨论了具有包晶反应的高温γ-TiAl合金的定向凝固与晶向控制， 分析了晶向控制中引晶、 合金化、 调节成分与凝固参量及它们的综合作用所得到的结果与存在的问题，并提出了此领域今后应注意的方面。
关键字: TiAl金属间化合物； 定向凝固； 晶向控制
（1. State Key Laboratory of Precision Hot Processing of Metals,
|Harbin Institute of Technology, Harbin 150001, China;
2. State Key Laboratory for Solidification Processing,
Northwestern Polytechnical University, Xi′an 710072, China）
Abstract:The directionally solidified microstructure of TiAl-based alloys which have potential applications in aerospace and energy industry is very helpful for improving its mechanical properties with respect to the orientational characteristic of γ+α2 lamellar. The orientation controlling of γ-TiAl during peritectic reaction or transformation was discussed from the view of the selection of phase and structure and the selected growth of crystal. The effects of seeding, alloying and adjusting of solidification parameters on the structure were analyzed. Many problems were revealed and that must be overcome in the future in order to get an optimum structure.
Key words: TiAl intermetallics; directional solidification; crystal orientation control
