喷射成形7055铝合金的应力腐蚀性能研究  

Study on Stress Corrosion Behavior of Spray Formed 7055 Aluminum Alloy

作　　者：乔及森[1] 杨敏杰[1] 夏浩[1] 赵文军[1] 夏天东[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,陇西748111

出　　处：《材料导报》2014年第10期93-96,共4页Materials Reports

基　　金：甘肃省科技重大专项(2011GS04134);甘肃省自然科学基金(1308RJYA046)

摘　　要：以喷射成形7055铝合金为研究对象,通过室温拉伸、光学显微镜和扫描电镜等分析方法,研究了载荷应力和浸泡时间对7055铝合金腐蚀性能的影响。研究结果表明,随着应力载荷的提高、腐蚀时间的延长,试样的强度并未出现明显的下降,但材料的塑性明显降低。腐蚀应力越接近材料的屈服强度,塑性下降越明显,抗拉应变和延伸率均降低,在腐蚀液中,极化曲线测试也表现出同样趋势。试样表层部分区域有明显的点蚀和晶间腐蚀空洞。拉伸时,腐蚀缺口处会产生明显的应力集中成为起裂源,导致材料塑性下降,从拉伸断口分析可知,断口边缘被腐蚀区域为明显的沿晶断裂。By means of tensile test,optical observation and scanning microscopy analysis,the corrosion property of 7055 aluminum alloy were studied under various loading condition at different immersing time The result shows that the extending of corrosion time and loading give rise to the deterioration of plasticity,by contrary,the tensile strength didn＇t decline distinctly during the test cycle.The closer the loading approached to the yield strength,the severer the plasticity decreased,which can be revealed from the elongation and tensile strains.And the polarization curve shows the same trend.Pits,intergranular voids and cracks were observed in the surface layer of the specimen.During the tensile test,the voids could cause stress concentration,and the crack source lead to the deterioration of plasticity.Intergranular fractures were observed on the edge of fracture morphology.

关 键 词：喷射成形 7055铝合金 应力腐蚀 力学性能 极化曲线 

分 类 号：TG146.2[一般工业技术—材料科学与工程]