Orientation behavior in TRC-ZA21 magnesium alloy with fine grain size during nano-indentation process

The deformation behavior in magnesium alloy was greatly affected by grain orientation. It is crucial to analyze the relationship between deformation mechanism and grain orientation. In this study, the deformation behaviors in grains possessing different orientations for TRC-ZA21 alloy with fine grain size were investigated using the nano-indentation deformation coupling EBSD method. The effects of grain orientation and grain boundary on deformation behavior and propagation of deformation mechanism were discussed. The results illustrated that the irregular performance of the nano-mechanical properties could be attributed the inconsistency of grain orientation as well as the grain boundary misorientation angle. Grain orientation, followed by the criterion of Schmid factor, regulated the deformation mechanism of grains that were in direct contact with the nano-indenter. This signified the orientation dependence in plastic deformation. The deformation behavior in grains, induced by plastic deformation and indirectly in contact with the nano-indenter, was found to be influenced by the grain boundary. The orientation difference in adjacent grains determines the influence of grain boundary in plastic deformation, revealing the competitive and coordinative behavior associated with these deformation mechanisms. The c-axes angle between adjacent grains was the key factor to determine the influence of grain boundary on deformation propagation.