Hot Deformation Behavior of the As-Cast Mg–10.13Li–2.83Zn–2.78Al–0.13Si Alloy

Abstract

Hot deformation behavior of Mg–10.13Li–2.83Zn–2.78Al–0.13Si alloy was investigated in the temperature range of 150–300 °C and strain rates from 0.001 to 10 s−1 by hot compression testing and a processing map was developed using Dynamic Material Model (DMM). According to the true stress–true strain curves, the flow stress behavior of the alloy was related to the coordinated deformation of α phase and dynamic recrystallization of β phase. The processing map exhibited only one safe domain occurring at 300 °C and 0.001 s−1 and its peak efficiency was 45%. The α phase had become fine and round because of the dissolution and precipitation behavior. But complete dynamic recrystallization occurred only in β phase. The instability region was also identified at the temperatures ranging from 150 to 220 °C and strain rates from 0.1 to 3 s−1. No defects, such as adiabatic shear bands or cracking, were observed in this region. Thus, the optimum thermal deformation parameter of the alloy in this experiment was 300 °C/0.001 s−1.