TC4-DT钛合金高周疲劳行为研究  

Research on High Cycle Fatigue Behavior of TC4-DT Titanium Alloy

作　　者：于兰兰[1,2] 毛小南[1] 李辉 赵永庆[1,2] 张鹏省[1] 侯智敏[1] 

机构地区：[1]西北有色金属研究院,陕西西安710016 [2]西北工业大学,陕西西安710072 [3]西部钛业有限责任公司,陕西西安710201

出　　处：《钛工业进展》2012年第6期11-14,共4页Titanium Industry Progress

基　　金：国家重点基础研究发展计划项目(2007CB613802)

摘　　要：对TC4-DT钛合金的高周疲劳性能及断口形貌进行了研究。结果表明:TC4-DT钛合金的S-N曲线(应力比R=-1)不出现呈水平线的疲劳极限,107次不被破坏的条件疲劳极限为550 MPa,置信度为95%;疲劳裂纹源均出现在试样的表面,疲劳裂纹扩展区较大说明材料具有较高的断裂韧度;疲劳裂纹扩展区由许多解理小刻面组成,解理面上可见疲劳条带及二次裂纹,以解理断裂为主;断裂区断口表面由许多互相连接的凹坑所组成,主要表现为韧窝断裂。The high circle fatigue properties and fractography of TC4-DT titanium alloy were studied. Results show that when the confidence is 95% , the S-N curve of TC4-DT titanium alloy （R = - 1 ） does not show the level fatigue limit and the conditional fatigue limit for 107 cycles is 550 MPa. Macrographs of fatigue fractography show that fatigue crack initiation is under the surface of specimens and the larger fatigue crack growth region displays that the material has higher fracture toughness. Mierographs of fatigue fractography reveals that fatigue crack growth region is composed of many small cleavage facet planes on which fatigue striations and crack braching are observed and the mode of frac- ture is cleavage fracture, fracture region consists of a lot of dimples and the mode of fracture is dimple fracture.

关 键 词：高周疲劳 钛合金 断口形貌 

分 类 号：TG146.23[一般工业技术—材料科学与工程]