快速凝固Ti_3Al基合金相变的X－射线衍射分析

X-RAY DIFFRACTION ANALYSES OF PHASE RELATIONSHIPS IN A RAPIDLY SOLIDIFIED Ti_3Al-BASED ALLOY

利用Ｘ－射线衍射分析研究了快速凝固Ｔｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１Ｍｏ合金回火的转变过程，结果表明，依照回火温度的不同，快速凝固合金中的亚稳β＿０相将产生不同的转变。在６００～８００℃之间回火时，亚稳β＿０相转变为Ｏ相；８１０℃回火时，合金的显微组织由Ｏ＋α＿２＋β＿０相组成；而９５０℃回火的合金的显微组织则为α＿２＋β＿０相，回火Ｏ相的晶格常数与Ｏ相形成温度有关。

The phase transformation in aging of a rapidly solidified Ti-25Al-10Nb-3V-1Mo alloy was studiedwith X-ray diffraction in this paper. The results show that metastable β_0 phase in rapidly solidified alloytransformed to different phases in the various temperatures. The isothermal β_0→O transition took place inthe alloy aged in the temperature between 600～800℃ while O+α_2+β_0 phases was found in the alloy agedat 810℃ and α_2+β_0 phases aged at 950℃.