Local deformation of Mg–7Gd–5Y–1.2Nd–0.5Zr magnesium alloy under high speed impact along extrusion direction

Abstract

The high strain rate deformation behavior of Mg–7Gd–5Y–1.2Nd–0.5Zr alloy was carried out at several temperatures. Through the truncated test of cap specimen, it was found that the local deformation occurred in the design shear zone, but no adiabatic shear band was observed. The deformation mechanism was mainly pyramidal slip, supplemented by prismatic slip, basal slip, and dynamic recrystallization. Among them, pyramidal 〈c + a〉 slip could coordinate deformation through the slip component along the 〈c〉 direction. The Johnson–Cook constitutive model and failure model were modified, and then the local deformation of the cap specimen along the extrusion direction was simulated by LS-DANY software. The results showed that the local severe deformation occurred in the area of the cap specimen with sharp change in shape, which was at an angle of 45 ° with the impact compression loading along extrusion direction. The temperature increased continuously with the amount of deformation until fracture occurred. The results showed that the alloy had high resistance to local high strain deformation and fracture.