Hot Deformation Behavior and Constitutive Equation of 5E61 Aluminum Alloy

Abstract

The hot deformation behavior of aluminum alloy 5E61 was studied by hot compressive tests using a Gleeble-1500 thermal simulator. The tests were performed at temperatures varying from 250°C to 500°C and strain rates ranging from 0.001 s-1 to 10s-1. The results achieved in the present study showed that the steady flow stress increases with decreasing temperature and increasing strain rate, in accordance with the Zener-Hollomon parameter. The related microstructure is sensitive to deformation temperature, strain rate and strain. The constitutive equation based on true stress-true strain curves has been developed by hyperbolic sine equation with the hot deformation activation energy of 153.907KJ/mol. The softening mechanism could be ascribed dominantly to dynamic recovery. The results of TEM observation suggested that Mn-containing particles and Al3(Er,Zr) phase have precipitated in the aluminum matrix and pin the dislocations, which could effectively inhibit the dynamic recrystallization.