Shear banding behavior in nanoscale Al/W multilayers

In this study, a series of nanoscale Al/W multilayers with different individual layer thicknesses were prepared by d.c. magnetron sputtering. Shear banding behavior was studied using the depth-sensing nanoindentation test at room temperature. By evaluating both deformation behavior and the morphology of the residual indentation, interestingly, contrary trends of the dependence of the shear banding behavior on the individual layer thickness were observed. A new parameter, which could represent the width of the pileup in residual indentation, was proposed; and the number of shear bands generated during deformation is strongly dependent on the parameter. To interpret the unique shear banding behavior in the Al/W multilayer, a physical model was proposed and the possible dominant mechanisms were suggested and extendedly discussed.