Strain induced dynamic recrystallization nucleation of ZA21 magnesium alloy during compression process at low and medium temperatures

Abstract

Dynamic recrystallization (DRX) behavior of ZA21 magnesium alloy during compression process was investigated through uniaxial compression tests at 110 °C and 210 °C with an initial strain rate of 0.01 s−1. Based on OM and detailed TEM characterization, preferential nucleation position of DRX grains at different compression temperatures were identified. The DRX grains preferential nucleation position under the conditions of low and medium temperatures are in grains and at grain boundaries, respectively. This is mainly caused by the inconsistency between intragranular strength and grain boundary strength. Grain boundary strength is higher than the intragranular strength at low temperature. But the intragranular strength is higher than the grain boundary strength at medium temperature. This leads to a difference in the ability to resist deformation between them, so that the site of the DRX priority nucleation is different. Keywords: ZA21 magnesium alloy, Compression, Dynamic recrystallization, Nucleation, Grain boundary