Microstructure and mechanical properties of cryo-rolled AA6061 Al alloy
(1. State Key Laboratory of High Performance Complex Manufacturing,
Central South University, Changsha 410083, China;
2. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
3. Light Alloy Research Institute, Central South University, Changsha 410083, China;
4.School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Central South University, Changsha 410083, China;
2. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
3. Light Alloy Research Institute, Central South University, Changsha 410083, China;
4.School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The microstructure and mechanical properties of the age hardening AA6061 Al alloy subjected to cryo-rolling (CR) and room temperature rolling (RTR) treatments were investigated. The rolled and aged alloys were analyzed by using DSC, EBSD, TEM, Vickers hardness analysis and tensile test. The results show that the cryo-rolled treatment has an effect on the precipitation sequence of AA6061 Al alloy.The ultrafine grain structures are formed to promote the fine second phase particles to disperse in the aluminum matrix after the peak aging, which is attributed to lots of dislocations tangled in the rolling process. Therefore, the strength and ductility of AA6061 Al alloy are simultaneously modified after the cryo-rolling and aging treatment compared with room temperature rolled one.
Key words: AA6061 Al alloy; cryo-rolling; ultrafine grain structure; disperse distribution; mechanical properties