作　　者： ; ; ; ;

机构地区： 东北大学材料与治金学院材料各向异性与织构工程教育部重点实验室

出　　处： 《特种铸造及有色合金》 2011年第1期5-7,101,共3页

摘　　要： 研究了缺口对铸造单一取向层片组织TiAl合金断裂形貌特征和断裂机制的影响。通过对断口进行观察发现,缺口对单一取向的层片组织有较大影响。研究表明,在光滑试样的拉伸过程中,裂纹起源于试样内部,然后迅速扩展至断裂;在缺口试样的拉伸过程中,微裂纹于断口边缘产生,在切应力的作用下扩展、连接形成裂纹稳态扩展区,然后在正应变控制下从裂纹稳态扩展区向裂纹失稳扩展区过渡,同时试样失稳。 Effects of notches on fracture morphology and fracture mechanism of casting TiAl alloy with monolithic orientation were investigated.Through observing fracture morphology,notches distinctly affect the lamellar structure of the alloy with monolithic orientation.During tensile testing process of smooth samples,crack is formed inside samples and then propagated to be broken,while for notched samples,micro-crack is generated at the edge of fracture,and then propagated in role of shearing stress to form steady propagation zone by each other connection.Furthermore,steady propagation zone is transformed into in-steady propagation under control of positive strain,so the crack propagation occurs.

关 键 词： 合金 缺口 断裂行为

领　　域： [金属学及工艺]