抄録
The effect of texture and grain boundary on indentation behavior was investigated using single crystal and fine-grained magnesium with an average grain size of 2-3 μm. Hardness of prismatic plane had 10-20% higher than that of basal plane. The fine-grained magnesium also showed slightly harder as compared with those of single crystal in the high strain rate ranges. However, these differences in hardness were very small as compared with the strength obtained from uniaxial testing methods, i.e., tensile and compression tests. The activation volumes indicated cross-slip as the rate-controlling mechanism during indentation tests, and they were not influenced by the initial microstructures. This was related to the formation of deformation twinning. The simulation results showed that the deformation twinning formed beneath tip with shaper radius at the beginning of indentation, irrespective for indentation planes, due to the creation of complex and large stress state.
