Hot compressive deformation behavior and microstructure characteristics of new ultra strength Al-Zn-Mg-Cu alloy

Abstract

The hot compression test of the new ultra strength Al-Zn-Mg-Cu-Zr-Sc alloy at high temperature was carried out by using the Gleeble-1500 thermal simulator. The flow stress and microstructure evolution during the deformation process of the new alloy were investigated at the deformation temperature 370-460℃, the strain rate 0.001-10s-1. The results show that the flow stress in the early deformation stage increases with the increase of the strain rapidly, and then the peak stress decreases gradually and reaches a steady state. The flow stress increases with increasing strain rate, and decreases with the increase of deformation temperature. The flow stress can be described with hyperbolic sine relationship, and material parameters such as activation energy can be calculated by linear fitting, thus the constitutive equation of flow stress can be presented finally. With the increase of the deformation temperature and the decrease of the strain rate, the deformation degree of the original grain increases significantly, and the recrystallization fraction increases obviously.

Keywords

• hot compression
• flow stress
• microstructure
• constitutive equation
• Al-Zn-Mg-Cu-Zr-Sc alloy