Fabrication of ultrafine-grained AA1060 sheets via accumulative roll bonding with subsequent cryorolling
(1. State Key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
2. Light Alloys Research Institute, Central South University, Changsha 410083, China;
3. College of Mechanical Engineering, Hunan Institute of Science and Technology, Yueyang 414000, China;
4. Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia)
2. Light Alloys Research Institute, Central South University, Changsha 410083, China;
3. College of Mechanical Engineering, Hunan Institute of Science and Technology, Yueyang 414000, China;
4. Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia)
Abstract: Ultrafine-grained (UFG) AA1060 sheets were fabricated via five-cycle accumulative roll bonding (ARB) and subsequent three-pass cold rolling (298 K), or cryorolling (83 K and 173 K). Microstructures of the aluminum samples were examined via transmission electron microscopy, and their mechanical properties were measured via tensile and microhardness testing. Results indicate that ultrafine grains in ARB-processed sheets were further refined by subsequent rolling, and the grain size became finer with reducing rolling temperature. The mean grain size of 666 nm in the sheets subjected to ARB was refined to 346 or 266 nm, respectively, via subsequent cold rolling or cryorolling (83 K). Subsequent cryorolling resulted in ultrafine-grained sheets of higher strength and ductility than those of the sheets subjected to cold rolling.
Key words: microstructure; AA1060 sheet; ultrafine-grained materials; cryorolling; accumulative roll bonding