2090铝锂合金中T_1(Al_2CuLi)相生长、粗化行为及微量稀土铈的作用

Behavior of Growth and Coarsening of T1(Al2CuLi) Precipitates in 2090 Aluminumlithium Alloy and Influence of Microamount Cerium

采用ＴＥＭ技术对２０９０和２０９０＋铈（ω＜０．１％）两种铝锂合金中Ｔ１（Ａｌ２ＣｕＬｉ）相生长及粗化行为进行了对比研究。含铈合金中Ｔ１相表现出较小的平均长厚比，这是由于该合金中不同变体间具有较多的交汇点所致。最大尺度的Ｔ１相随时效时间的变化，明显地分为生长和粗化两个阶段。利用Ｔ１相的生长动力学曲线对铜和锂原子的扩散系数进行了计算。

The behavior of growth and coarsening of T1(Al2CuLi) precipitates in two aluminumlithium alloys of 2090 and 2090+Ce (<0.1 wt%) alloys aged at 190 for 348 h were comparatively studied by means of TEM technique. Statistical and analystical results show that T1 precipitates in the alloy containing trace addition of cerium have smaller aspect ratio, which is connected with the more intersections between different T1 variants in this alloy. It is also found in experiment that the variation course of maximum length of T1 precipitates with aging time can be obviously divided into two stages of growth and coarsening. The diffusion coefficients of solute atoms of Cu and Li are calculated via growth kinetics curves of T1 precipitates. The results show that the diffusion of atom Cu will play a more important role in the formation of T1 precipitates.