Effect of Grain Size on Dynamic Compression Behavior and Deformation Mechanism of ZK60 Magnesium Alloy

The dynamic compression deformation of 3 µm, 15 µm and 25 grain size ZK60 alloys under high-strain-rate is systematically studied. Dynamic experiments at a strain rate 1700 s−1 were conducted using split Hopkinson pressure bar, the microstructure specimen was characterized via electron backscatter diffraction transmission microscopy, as well calculation Schmid factors. results showed that alloy exhibited decrease in yield strength peak stress increased compression. refinement conducive to activation basic slip. In turn, an increase caused transition main mechanism from pyramidal <a> slip {10−12} tensile twinning Based on these mechanisms, Johnson-Cook constitutive equation with different sizes modified, fitting accordance experimental data.