7055铝合金恒载荷应力腐蚀性能及机理研究  

Mechanism Study and Stress Corrosion Property of 7055 Aluminum Alloy under Constant Load Condition

作　　者：夏浩[1] 杨敏杰[1] 夏天东[1] 赵文军[1] 乔及森[1] 张涵[1] 段瑞芬 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,兰州730050 [2]中国铝业西北铝加工分公司,甘肃陇西748111

出　　处：《有色金属（冶炼部分）》2013年第10期51-55,共5页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金资助项目(51065016);甘肃省留学人员科技资助项目(1001ZBS113)

摘　　要：采用室温拉伸、光学显微镜和扫描电镜研究了不同恒载荷条件下7055铝合金型材的应力腐蚀性能。结果表明,在腐蚀周期内,随着应力腐蚀载荷的提高,试样的强度并未出现明显的下降,而塑性下降40%。应力腐蚀载荷越接近材料的屈服强度,塑性下降就越明显,抗拉应变和延伸率均有降低。应力腐蚀试样表层部分区域有明显的点蚀、沿晶腐蚀空洞和裂纹;拉伸时,腐蚀缺口处会产生明显的应力集中而成为起裂源,拉伸断口边缘被腐蚀区域为明显的沿晶断裂。The stress corrosion resistance of 7055 aluminum alloy under different constant loadings was studied by tensile test under optical and electron microscopy observation.The results show that the tensile strength presents no obvious decline while the plasticity decreases 40％ during the test cycle.The closer load approaches yield strength,the severer decrease of plasticity （i.e.elongation and tensile strain） is.Pittings and intergranular voids and cracks are observed on surface layer of specimen.During the tensile test,the stress concentration in voids could become crack source,leading to deterioration of plasticity.Intergranular fracture is observed on the edge of fracture surface.

关 键 词：喷射成型 7055铝合金 应力腐蚀 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG174.3[金属学及工艺—金属材料]