喷射成形GH738合金的疲劳裂纹扩展行为  

Fatigue Crack Growth Behavior of Spray Formed GH738 Alloy

作　　者：杨冬野[1,2,3] 曹福洋[1,2] 许文勇[3] 左欣[1,2] 李周[3] 张国庆[3] 孙剑飞[1,2] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [2]哈尔滨工业大学金属精密热加工国防科技重点实验室,哈尔滨150001 [3]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《材料工程》2014年第7期55-59,共5页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51074145);国家973计划资助项目(2010CB631205)

摘　　要：进行了不同温度、频率和应力比条件下喷射成形GH738合金紧凑拉伸(CT)试样的疲劳裂纹扩展试验,分析了相应条件下的疲劳裂纹扩展速率及其对疲劳裂纹扩展行为的影响规律。结果表明:随着温度的升高,裂纹扩展速率略有加快;加载频率降低,疲劳裂纹扩展加速;裂纹扩展速率da/d N随应力比R的增大而增大。疲劳断口呈现多裂纹源特征,裂纹稳定扩展为疲劳条带机制。The fatigue crack growth tests of spray formed GH738 superalloy with compact tension（CT） specimens were carried out at different temperatures, loading frequency and R-ratios. Theeffects of temperatures, loading frequency and R-ratios on fatigue crack growth behaviors were inves-tigated. The results show that the crack propagation rate increases with the increase of temperature;Fatigue crack propagation increases with the decrease of loading frequency; Fatigue crack growth rateda/dN is also found to increase with the larger R-ratios. The crack initiates multi-sites, and the fa-tigue fracture individually exhibits a series of fatigue striations mode in the crack steady growth re-gion.

关 键 词：喷射成形 GH738 疲劳裂纹扩展 

分 类 号：TG146.1[一般工业技术—材料科学与工程]