Influence of high-temperature and short-time solution treatment on microstructure and properties of Al-Mg-Zn-Ag alloy
(1. School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China;
2. Key Lab of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China;
3. High-Performance Metal Structural Materials Research Institute, Soochow University, Suzhou 215021, China)
2. Key Lab of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China;
3. High-Performance Metal Structural Materials Research Institute, Soochow University, Suzhou 215021, China)
Abstract: High-temperature and short-time (HTST) solution heat treatment combined with non-isothermal aging (NIA) was employed to regulate the microstructure and properties of Al-4.5Mg-2.0Zn-0.3Ag alloy. Results indicate that HTST solution heat treatment can not only retain partial deformation dislocations, but inhibit the recrystallization behavior and increase the proportion of low-angle grain boundaries (LAGBs). In the subsequent NIA process, HTST solution heat treatment combined with NIA is instrumental in restraining the degradation of dislocations and promoting precipitation of nano-scale T''''-Mg32(Al,Zn,Ag)49 phase, which improves the strength of the alloy greatly. In addition, a higher fraction of LAGBs and the discontinuous distribution of grain boundary precipitates caused by this novel technology meliorate the corrosion resistance of Al-4.5Mg-2.0Zn-0.3Ag alloy.
Key words: Al-Mg-Zn-Ag alloy; solution treatment; non-isothermal aging; microstructure; mechanical properties; corrosion resistance