The influence of grain morphology on indentation deformation characteristic of metallic nano-multilayers

The microstructure and indentation behavior of Ag/Co, Ag/Cu, Ag/Ni, Cu/W and Ni/Ru multilayers were investigated. The results indicate that the deformation characteristic is influenced by grain morphology. The Ag/Co and Ag/Cu with equi-axed grains deform by shear bands, while the Ag/Ni and Cu/W with compressed grains deform homogenously. This difference is interpreted by cooperative grain boundary sliding which can occur only in equi-axed grain materials. For Ni/Ru multilayer, the shear bands may occurs by shear sliding of adjacent columns.