Sliding wear-induced microstructure evolution of nanocrystalline and coarse-grained AZ91D Mg alloy

Wear behavior of nanocrystalline (NC) AZ91D Mg alloy generated by surface mechanical attrition treatment and the corresponding coarse-grained (CG) samples subjected to dry sliding wear at different sliding velocities were investigated. The subsurface microstructure evolution of these two samples was analyzed by cross-sectional transmission electron microscope. The microstructure of NC layer was almost unchanged while grain refinement into nanometer scale was identified for CG sample at high velocity, which contributed to the wear behavior of both NC and CG samples.