Microstructural Features of AZ31 Deformed at High Temperatures

Abstract

Abstract An as-cast AZ31 magnesium alloy was investigated using light microscopy (LOM) and electron backscatter diffraction (EBSD) methods to quantify and describe the deformation mechanisms activated at high temperatures. Compression tests were carried out by means of a Gleeble®1500 device in the range of 320–500°C and 0.03–10 s-1 of strain rate. Deformed samples were simulated by finite elements method to correlate the microstructure with the local deformation parameters. EBSD measurements were used to distinguish and quantify the new recrystallized grains and to characterize the misorientation distribution. These results helped to determine the grain size distribution with the temperature and the strain rate by LOM pictures. Dynamic recrystallization is denoted by necklace microstructure, and twinning promotes the recrystallization nucleation. At high temperature and slow strain rate recovery takes place followed by continuous dynamic recrystallization.