Characterization of nanoindentation damage in metal/ceramic multilayered films by transmission electron microscopy (TEM)

Al/SiC multilayered films composites, with alternating layers of Al and SiC of 50 nm nominal thickness, were synthesized by magnetron sputtering. The composite was subjected to different degrees of deformation using nanoindentation. The cross-sections of as-deposited and indented laminates were examined by transmission electron microscopy (TEM). The as-deposited layers showed well defined interfaces with no internal damage. Severe deformation of the Al and SiC layers, along with cracking in SiC, were found after indentation. There was no observable dislocation activity within the Al grains in all samples. The shape change of Al grains, caused by the extrusion effect underneath the indentation, was quantified in detail. Numerical modeling was also employed to illustrate the dimensional change of the Al layers.