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

摘要: 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Y₃(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TiAl₂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Ti₃Al和TiAl₃相中固溶度很小,均小于(原子)0.1%。

Abstract: 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(Al_xTi_1-x)₂ and Y₃(Al_xTi_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).