Microstructure evolution and mechanical responses of Al–Zn–Mg–Cu alloys during hot deformation process

Al–Zn–Mg–Cu alloys can be fabricated by a series of thermo-mechanical processing methods (e.g., hot rolling, forging and extrusion), which is able to serve in aeronautic, automobile, and marine industries because of its excellent physical properties. However, reaching the balance between high strength and favorable ductility to present its high performance is still in progress, during which temperature and strain rate are two very important external variables. More importantly, the core lies in sophisticated microstructure evolution paths involved in hot deformation, which consists of different microstructure mechanisms and behaviors and can be expressed as various mechanical responses. Therefore, a fundamental review of microstructure mechanisms and behaviors, microstructure evolution and relevant mechanical responses of Al–Zn–Mg–Cu alloys during high-temperature deformation is of great significance. In present paper, first, various experimental methods have been introduced. Second, general trends of mechanical properties changing with temperature and strain rate have been summarized. Third, major microstructure mechanisms and behaviors have been discussed. Then, a schematic illustration originating from dislocations’ movement has been depicted, which succeeding microstructure evolution and mechanical responses (including superplasticity) have been reviewed accordingly. Finally, further suggestions of hot deformation of Al–Zn–Mg–Cu alloys have been given.