(中南大学 粉末冶金国家重点实验室， 长沙 410083)
摘 要: 利用光学显微镜（OM）和TEM，研究了全层状TiAl合金的层片间距的影响因素及与各因素的关系。 实验结果表明， 全层状TiAl合金的层片间距与冷却速度和合金中铝含量有关， 层片间距与冷却速度呈反比关系， 并随着合金中铝含量的增加而增加。 同时，以层片生长的台阶机制为基础， 推导出了全层状TiAl合金在连续冷却过程中层片间距的数学表达式， 推导结果与实验结果相符。
关键字: TiAl合金； 层片间距； 冷却速度； Al含量
（State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:It is important to control the lamellar spacing of fully lamellar TiAl alloy for improving its mechanical properties. The factors affecting the lamellar spacing of fully lamellar TiAl alloy and the dependence of the lamellar spacing on the factors were investigated by means of OM and TEM. The results show that the lamellar spacing depends on cooling rate and Al content. The lamellar spacing is inversely proportional to cooling rate and increases with the increase of Al content. At the same time, a theoretical expression of the lamellar spacing of fully lamellar TiAl alloy during continuous cooling has been derived on the basis of the ledge mechanism of lamellae growth. The theoretical results are in agreement with the experimental findings.
Key words: TiAl; lamellar spacing; cooling rate; Al content
