Si及热处理对Al- Zn- Mg- Cu合金显微组织和腐蚀行为的影响  

Influences of Si and Heat Treatment on Microstructures and Corrosion Behaviors of Al-Zn-Mg-Cu Alloys

作　　者：焦慧彬 陈康华 杨振 陈送义 王会平 马云龙 JIAO Huibin;CHEN Kanghua;YANG Zhen;CHEN Songyi;WANG Huiping;MA Yunlong(Light Alloy Research Institute,Central South University,Changsha 410083,Hunan,China;Collaborative Center of Advance Nonferrous Structural Materials and Manufacturing ,Central South University ,Changsha 410083 ,Hunan ,China;Beijing Institute of Astronautical Systems Engineering ,Beijing 100076 ,China)

机构地区：[1]中南大学轻合金研究院,湖南长沙410083 [2]中南大学有色金属先进结构材料与制造协同创新中心,湖南长沙410083 [3]北京宇航系统工程研究所,北京100076

出　　处：《华南理工大学学报（自然科学版）》2018年第11期68-75,共8页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家重点研发计划项目(2016YFB0300801);国家自然科学基金重大科研仪器设备研制专项(51327902)~~

摘　　要：采用慢应变速率试验研究了不同Si含量及热处理条件下Al-Zn-Mg-Cu合金的应力腐蚀开裂(SCC)行为,并使用透射电子显微镜和统计分析确定晶界微观结构.研究表明,Si含量和时效程度的增加都能改善合金的抗应力腐蚀性能.晶界析出相(GBP)面积分数是评估SCC敏感性的重要参数.对于不同时效程度的Al-Zn-Mg-Cu-0.16Zr-0.04Si合金,当GBP的面积分数相对较低时,SCC的主导机制是氢脆;对于峰时效状态下的Al-Zn-Mg-Cu合金和Al-Zn-Mg-Cu-0.16Zr-0.02Si合金,当GBP的面积分数足够高时,阳极溶解主导SCC行为.The stress corrosion cracking(SCC) behavior of Al-Zn-Mg-Cu alloys with different Si contents and heat treatments was studied by using slow strain rate test, and the grain boundary microstructures were identified by means of transmission electron microscopy(TEM) and statistical analysis. It is found that the SCC resistance of alloys can be improved by increasing the Si content or aging degree. Grain boundary precipitates(GBP) area fraction is found to be an important parameter to evaluate the SCC susceptibility. It is revealed that, for Al-Zn-Mg-Cu-0.16 Zr-0.04 Si alloys with different aging degrees, hydrogen-induced cracking dominates the SCC when the area fraction of GBP is relatively low;while for peak-aged Al-Zn-Mg-Cu and Al-Zn-Mg-Cu-0.16 Zr-0.02 Si alloys, ano-dic dissolution dominates the SCC when the area fraction of GBP is sufficiently high.

关 键 词：铝合金 应力腐蚀开裂 晶界 腐蚀行为 

分 类 号：TG146.21[一般工业技术—材料科学与工程]