中文摘要：

采用水冷铜坩埚感应熔炼制备了Ti-45Al-8.5Nb-0.5（W,B,Y）（at%）合金铸锭,研究了铸造合金组织特点及均匀化处理温度对显微组织的影响规律。结果表明,铸锭组织呈全层片,有大量β相网,富Al相等成分偏析;调整热处理温度使合金偏析区域处于α单相区,充分保温后缓慢冷却可消除偏析形成全层片组织;经过1420℃×12 h炉冷,β相与富Al相偏析均得以消除,获得平均尺寸约为320μm,层片间距约为0.8μm的均匀全层片组织。

英文摘要：

Ti-45Al-8.5Nb-0.5 （ W, B, Y ） （ at% ） ingot was prepared using an induction furnace with a water-cooled copper crucible. The microstructure of the ingot and the effect of the homogenizing temperature on the microstructure were studied. The results show that the ingot exhibits full lamellar mierostrueture with a large amount of network β phase and Al-rich phase segregations. The segregations can be efficiently eliminated through heat treatment at the c~ phase region of the segregation area, and after fully holding then slowly cooling down, the uniform fully lamellar mierostructure can be obtained. Heat treated at 1420 ℃ for 12 h with furnace cooling, the alloy exhibits full lamellar microstructure without β phase and Al-rieh phase, and the average grain size and lamellar spacing are 320 μm and 0.8 μm, respectively.