一引言钛合金具有强度高,比重小,耐高温抗腐蚀等优点。所以在宇航、航空、化工、海洋、医疗等方面得到广泛应用。许多钛合金构件常工作在高温应力状态下,因而要求它具有优良的力学性能和高温性能。另外在加工和使用中不可避免地会出观微裂纹等缺陷,它在高温下会扩展导致构件失效,故高温蠕变裂纹扩展速率da/dt亦是重要力学参数之一。从大量高温故障分析可看到:断口往住是沿晶或混合型特征。说明材料高温热强性不足,蠕变裂纹扩展是高温构件失效的一种形式。因此,研究材料在蠕变条件下裂纹扩展的规律对合理选材,改进工艺,确 An introduction Titanium alloy with high strength, small proportion, high temperature corrosion resistance and so on. So in the aerospace, aviation, chemical, marine, medical and other aspects of a wide range of applications. Many titanium alloy components often work under high temperature stress conditions, thus requiring it with excellent mechanical properties and high temperature performance. In addition, during processing and use, some defects such as microcracks inevitably occur, which will cause failure of components at high temperature. Therefore, the da / dt at high temperature creep crack growth is also one of the important mechanical parameters. From a large number of high temperature failure analysis can be seen: the fracture is to live along the crystal or hybrid features. This shows that the material is insufficient in high-temperature thermal strength and creep crack growth is a form of failure of high-temperature components. Therefore, the study of material creep crack growth under the law of the rational selection of materials, improve the process, and indeed