Abstract
Hot deformation behaviors of a ZK60 magnesium alloy were investigated by hot compressive tests on a Gleeble-1500 thermal simulation test machine at temperatures ranging from 473 K to 723K and strain rates of 0.01-1s-1. Microstructures evolution of the alloy as well as dynamic recrystallization mechanisms at different strains with the strain rate 0.1s-1 at 623K were examined under optical microscope (OM) and transmission electron microscope (TEM). The relationships between flow stress, strain rate and deformation temperature were analyzed, and the deformation activation energy at elevated temperatures (573-723K) were calculated. The results indicated that under the present deformation conditions, dynamic recrystallization happened in the alloy and fine recrystallized grains tended to form ductile shear zones under the large strain condition; and there were different dynamic recrystallization mechanisms at different strains; within the temperature range from 573K to 723K, deformation activation energy changed with the deformation temperature and strain rate.
