Tensile behavior of 40 nm Cu/Nb nanoscale multilayers

Until recently, mechanical testing of nanoscale multilayers has largely involved nanoindentation, and few studies have carried out tensile testing of freestanding samples. In this study, freestanding Cu/Nb multilayers with equal individual layer thickness of 40 nm are tested in tension. The material exhibits a flow stress of 1.55 GPa and elongation to failure of 3.4%, in agreement with the strength ascertained by nanoindentation. Fracture surface analysis reveals evidence of ductile fracture, with little necking occurring prior to failure.