6156铝合金疲劳裂纹的扩展速率  

Proagation Rate of Fatigue Crack of 6156 Aluminum Alloy

作　　者：佘玲娟[1] 郑子樵[1] 钟警[1] 林莉[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《机械工程材料》2011年第5期19-22,26,共5页Materials For Mechanical Engineering

基　　金：国家重点基础研究发展规划项目(2005CB623705)

摘　　要：针对不同时效状态、相同时效状态在不同应力比(0.1,0.5)和不同方向(L-T,T-L)的6156铝合金的疲劳裂纹扩展速率进行了研究;同时还用透射电镜及扫描电镜对合金的显微组织与断口形貌进行了观察。结果表明:不同时效状态下,在疲劳第Ⅰ和第Ⅱ阶段,自然时效态合金的疲劳裂纹扩展速率最小,T6欠时效态的较大,T6过时效的最大,T6峰时效的介于T6欠时效和过时效之间;应力比为0.5时合金的疲劳裂纹扩展速率比应力比为0.1时的大;取样方向对裂纹扩展速率几乎没有影响,6156铝合金的抗疲劳性能无明显的各向异性。The fatigue crack propagation（FCP） rate of 6156 aluminum alloy in various aging states were studied.In addition,the effects of different stress ratios（0.1,0.5） and orientations（L-T,T-L）in same aging states on FCP rate also were investigated.The microstructure and fracture morphology of the alloy were examined by using TEM and SEM.The results show that nature-aged alloy had the mininum FCP rate,followed by under-aged alloy in T6 in the first stage and the second stage of fatigue,and over-aged alloy in T6 had the largest FCP rate,while peak-aged alloy in T6 was between under-aged alloy and over-aged alloy in T6.The fatigue crack propagation rate of stress ratio 0.5 was bigger than that of stress ratio 0.1.Orientations had little effects on the fatigue crack propagation,6156 aluminum alloy had not obvious anisotropic of fatigue property resistance.

关 键 词：6156铝合金 疲劳裂纹扩展速率 应力比 时效 

分 类 号：TU512.4[建筑科学—建筑技术科学] TG115.5[金属学及工艺—物理冶金]