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. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.