(1．中国科学院 金属研究所，沈阳 110016；
2. Department of Materials Engineering, Monash University, Melbourne 3800, Australia)
摘 要: 对热等静压处理前后的TC4薄壁铸件进行疲劳裂纹扩展速率测试。利用光学显微镜和扫描电镜观察材料的显微组织、疲劳断口形貌和疲劳裂纹扩展路径。结果表明：经热等静压后，疲劳裂纹扩展速率增大，主要是因为α板条和集束尺寸的增加减少了集束界面对裂纹的阻碍作用。
关键字: TC4；热等静压；裂纹扩展速率；晶体取向
（1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016;
2. Department of Materials Engineering Monash University, Melbourne 3800, Australia）
Abstract:Fatigue crack growth rates testings were carried out on as-cast TC4 thin wall structure component before and after hot isostatic pressing (HIP). The microstructure, fatigue fracture fractography and crack paths were observed by means of optical microscopy and scanning electron microscopy. The results show that fatigue crack growth rate increases after HIPping, which is mainly because the resistance of colony interfaces to crack growth is reduced as a result of the increase of the size of α platelets and colonies.
Key words: TC4; hot isostatic processing; fatigue crack growth rate; crystal orientation
