摘要
以分别具有再结晶和纤维晶粒组织的两种Al-Zn-Mg合金为研究对象,通过室温拉伸、剥落腐蚀、慢应变速率拉伸、四点弯曲试验,结合金相显微镜(OM)、透射电镜(TEM)、扫描电镜(SEM)、电子背散射衍射(EBSD)观察研究了晶粒组织对合金力学性能和腐蚀性能的影响。结果表明:纤维组织合金相比于再结晶组织合金屈服强度提高24.7 MPa,抗拉强度提高56 MPa;纤维组织合金表现出更优的抗应力腐蚀性能,其在慢应变速率拉伸试验中的抗拉强度以及伸长率的损失率分别比再结晶组织合金降低了65.2%和80.3%,应力腐蚀指数降低了75.5%,在四点弯曲试验过程中发生断裂的时间是再结晶组织合金的57倍;纤维组织合金的剥落腐蚀性能低于再结晶组织合金,其最大腐蚀深度增加了160.4%。纤维组织合金的力学性能的提升主要来自细晶强化作用,抗应力腐蚀性能的提升主要源于其较低的再结晶分数和较低的大角度晶界占比。
Taking Al-Zn-Mg alloys with two different grain structures,recrystallized and fibrous as the research object,through room temperature tensile,exfoliation corrosion,slow strain rate tensile,four-point bending tests,the effects of grain structure on the mechanical properties and corrosion properties of the alloy were investigated by OM,TEM,SEM and EBSD.The results showed that:compared with the recrystallized structure alloy,the yield strength of the fiber-structured alloy was increased by 24.7 MPa and the tensile strength was increased by 56 MPa,the tensile strength and elongation loss rate in the slow strain rate tensile test were 65.2%and 80.3%lower than those of the recrystallized alloy,and the stress corrosion index was reduced by 75.5%,the time to fracture during the four-point bending test was 57 times longer than that of recrystallized alloys,compared with the recrystallized structure alloy,the maximum corrosion depth of exfoliation corrosion of the fiber structure alloy was increased by 160.4%.The improvement of the mechanical properties of the alloy with fibrous structure was mainly due to the grain refinement strengthening effect,and the improvement of the stress corrosion resistance was mainly due to its lower recrystallization fraction and lower proportion of high-angle grain boundaries.
作者
王鹏宇
叶凌英
柯彬
胡恬娇
董宇
刘胜胆
WANG Pengyu;YE Lingying;KE Bin;HU Tianjiao;DONG Yu;LIU Shengdan(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Key Laboratory of Nonferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China)
出处
《材料导报》
CSCD
北大核心
2023年第19期169-175,共7页
Materials Reports
基金
河南省紧固连接技术重点实验室项目(JGLJ2103)
国家重点研发项目(2016YFB0300901)。
