作　　者： ; ; ; ; ; ;

机构地区： 中南大学材料科学与工程学院粉末冶金国家重点实验室

出　　处： 《中国有色金属学报》 2011年第4期777-783,共7页

摘　　要： 采用光学显微镜、扫描电镜及透射电镜研究微量B和Y对铸造Ti-Al-Nb-W合金显微组织的影响。结果表明:Ti-47Al-4Nb-0.6W合金的基本凝固路线为L→β+L→(β+α)+L→(β+α)+γ→α+γ→(α+γL)+γ→(α2+γL)+γ,添加微量B和Y并未改变其基本凝固路径;微量B元素在合金中以短棒状TiB2相存在,细化了铸造Ti-47Al-4Nb-0.6W合金的晶团尺寸及片层间距;微量稀土Y元素主要以Y2O3氧化物颗粒的形式分布于片层晶团界面处,在B和Y的共同作用下,合金的片层晶团尺寸以及片层间距进一步减小。 The effects of trace elements B and Y on the microstructures of cast Ti-Al-Nb-W alloy were investigated by optical microscopy,scanning microscopy and transmission electron microscopy.The results show that the following sequence of phase transformations takes place during the solidification of the Ti-47Al-4Nb-0.6W alloy as： L→β＋L→（β＋α）＋L→（β＋α）＋γ→α＋γ→（α＋γL）＋γ→（α2＋γL）＋γ.The solidification sequence remains unchanged after adding of trace elements B and Y.With the addition of a small amount of element B,the original colony and lamellar sizes of the Ti-47Al-4Nb-0.6W alloy are refined due to the formation of short-stick shaped TiB2 phases.The rare earth element Y is mainly distributed along the boundaries of the colonies in the form of Y2O3 particles.A further refined microstructure can be obtained as a result of the combined effects of elements B and Y.

关 键 词： 基合金 显微组织 铸造合金

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]