Hot Deformation Behavior and Processing Maps of As-Homogenized Mg-Gd-Y-Zn-Mn Alloy

Abstract

The hot deformation behavior and processing maps of as-homogenized Mg-Gd-Y-Zn-Mn alloy were investigated by hot compression tests performed at 350∼500 °C and strain rates ranging from 0.001 s−1 to 1 s−1. The constitutive equation was established using hyperbolic law, and the activation energy of the alloy was calculated to be about 260.94 kJ/mol. Based on the dynamic material model, processing maps of as-homogenized Mg-Gd-Y-Zn-Mn alloy deformed at strain values of 0.6, 1.2 were drawn to study the hot workability of the alloy. The processing map developed at a strain of 1.2 shows two safety domains: one occurring at 460~500 °C and strain rates ranging from 0.001 s−1 to 1 s−1; the other occurring at 350~500 °C, and strain rate ranging from 0.001 s−1 to 0.005 s−1. The corresponding microstructure evolution, with particular emphasis on the deformation mechanism of long-period stacking ordered phase (LPSO) in this alloy, was also discussed.