Evolution of precipitates in ZK60 magnesium alloy during high strain rate deformation

High strain rate(6.2 x 10(4) s(-1)) loading of ZK60 magnesium alloy was carried out with radial collapse of a thick-walled cylinder technology. The evolution of precipitates in solution-treated and peak-aged ZK60 magnesium alloy during high strain rate deformation was studied by transmission electron microscopy (TEM) for the first time. A large number of elongated rod-like phase were precipitated in solution-treated sample after impacting; the rod-like phases in peak-aged sample experienced shortening and thinning, and some of which finally transformed into spherical-like phases, namely the rod-like phases were preliminarily dissolved into the matrix. Based on thermodynamics and kinetics analyses, the high strain rate, high density dislocation, high shear stress and adiabatic temperature rise induced by explosive impact process make it possible for precipitates to precipitate and dissolve preliminarily within about 3.1 mu s. (C) 2017 Elsevier B.V. All rights reserved.