Dynamic Deformation Mechanism Transformation and Constitutive Equation Modification of ZEK610 Alloy

The hot extrusion shear technique was employed to fabricate the Mg-6Zn-1Ce-0.6Zr (ZEK610) alloy, primarily composed of α-Mg matrix, Mg₇Zn₃ phase, and (Mg_1 − xZn_x) ₁₁Ce phase. Dynamic compression experiments at various strain rates were conducted on the alloy. The alloy exhibits a typical positive strain strengthening effect, with the yield strength and peak stress reaching 243Mp and 622Mp at 2500s^− 1 strain rate. The dominant deformation mechanism of the alloy transforms from {10\(\stackrel{-}{1}\)2} tensile twining to prismatic slip as the strain rate increases. This phenomenon is attributed to the increased sensitivity of both the absorbed energy density and the adiabatic temperature to strain rate increments. After modifying the Johnson-Cook constitutive model, it was possible to more accurately predict the dynamic compression properties of the alloy at room temperature, as the curves derived from the modified equations closely matched the experimental curves.

Graphical Abstract