Microstructure transformation of deformed AZ91D during isothermal holding
(1. Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering,
Southeast University, Nanjing 211189, China;
2. Key Laboratory of Automobile Materials of Ministry of Education, School of Materials Science and Engineering,
Jilin University, Changchun 130022, China)
Southeast University, Nanjing 211189, China;
2. Key Laboratory of Automobile Materials of Ministry of Education, School of Materials Science and Engineering,
Jilin University, Changchun 130022, China)
Abstract: In order to understand the thermodynamic properties of deformed AZ91D alloy during isothermal holding, the microstructure characteristics and transformation were investigated. The results present that deformation mainly concentrates on the edge of the chips and billets, especially at the interface of α/β. Microstructure transformation mechanism of deformed AZ91D during holding mainly includes recrystallization, spheroidization and Ostwald ripening. The mechanism was then thermodynamically analyzed. During the heating and isothermal holding process, recrystallization driven by residual energy within the deformed AZ91D alloy, spheroidization and Ostwald ripening induced by the reduction of interfacial energy, will inevitably and continuously occur with the extension of heating and holding.
Key words: AZ91D magnesium alloy; deformation; isothermal holding; microstructure transformation