Effect of deformation temperature on microstructure and texture of AZ31 magnesium alloy processed by new plastic deformation method
(1. School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;
2. Hunan Jinfeng Mechanical Technology Co., Ltd., Loudi 417700, China;
3. Key Laboratory of Efficient & Clean Energy Utilization, School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha 410114, China;
4. Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China)
2. Hunan Jinfeng Mechanical Technology Co., Ltd., Loudi 417700, China;
3. Key Laboratory of Efficient & Clean Energy Utilization, School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha 410114, China;
4. Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China)
Abstract: A new method of repeated upsetting-extrusion (RUE) deformation was presented. The effects of different deformation temperatures on the microstructure and texture of RUE deformed AZ31 magnesium (Mg) alloy were studied using optical microscopy (OM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD), and Vickers hardness tester. The results show that the microstructure of the AZ31 Mg alloy is locally refined to 0.8 μm after RUE deformation, and the main refinement mechanism is the continuous dynamic recrystallization (CDRX). As the temperature increases, the texture of basal plane parallel to shearing plane is formed firstly, followed by texture with weaker intensity, and finally and textures. The texture split is caused by the dislocation slip of basal áa？ and pyramidal áa？. The maximum hardness of the AZ31 Mg alloy after RUE deformation is increased by 42.4% compared with that at the initial state, which is mainly due to the fine-grained strengthening and the dislocation strengthening.
Key words: AZ31 Mg alloy; repeated upsetting-extrusion; dynamic recrystallization; texture; hardness