Effect of temperature and strain rate on the mechanisms of indentation deformation of magnesium

Dual-stage, constant loading-rate followed by constant-load, pyramidal indentation experiments were performed to investigate the strain-rate (10 −5 –10 −1 /s) and temperature (295–573 K) dependence of pure magnesium. The estimated total activation energy, Q (0.69–1.01 eV), and apparent activation volume, V * (17–28b 3 ), indicate that plastic deformation is controlled by a dislocation cross-slip mechanism. The results from this work and previous studies confirm that, during pyramidal indentation of Mg, the operative deformation mechanism remains the same over a very wide strain-rate and temperature range.