Ti—Al—Y三元系相图1000℃部分等温截面重新确定

Re-Determination of 1000℃ Partial Isothermal Section of the Ti-Al-Y Ternary System

利用扩散偶局部平衡原理，通过金相观察和电子探针微区成分分析，重新测定了１０００℃下Ｔｉ—Ａｌ—Ｙ三元系部分等温截面相图。首次发现该系在１０００℃存在两个三元化合物均相区ｙ（Ａｌ_ｘＴｉ_（１－ｘ））_２（Ｘ＝８０％～１００％）和Ｙ_３（Ａｌ_ｘＴｉ_（１－ｘ））_２（ｘ＝８０％～１００％）．改变了以前发表的关于Ｔｉ—Ａｌ—Ｙ三元相图１０００℃等温截面的研究结果。此外在所测部分等温截面相图中存在６个单相区、９个两相平衡区、４个三相平衡区。１０００℃下Ｙ在ＴｉＡｌ和ＴｉＡｌ_２相中存在１个固溶区，其最大固溶度分别为（原子）１．２５％和４．２０％；Ｙ在Ｔｉ_３Ａｌ和ＴｉＡｌ_３相中固溶度很小，均小于（原子）０．１％。

The 1000℃ partial isothermal section of Ti-Al-Y ternary phase diagram has been re-determined by using diffusion couple, electron microprobe analysis and metallography. The homogeneity ranges of two temary compounds Y(AlxTi(1-x))2 and Y3(AlxTi(1-x))2 (x=80%～100%) at 1000℃ have been discovered. Six single phase regions. nine tow phase regions and four three phase regions have been determined in the studied partial isothermal section. The max. solid solubilities of Y in TiAl and TiAl2 were found to be 1.25%(atom) and 4.20%(atom) respectively. However, those in Ti3Al and TiAl3 were found to be lowrr 0.1%(atom).