Effects of size and amorphous layer structure on the strength and plasticity of Cu/CuZr nanolaminates

Abstract Cu/CuZr nanolaminates with varying individual layer thickness and CuZr layer structure were prepared by magnetron sputtering on single-crystalline Si (100) and polyimide film substrates. Nanoindentation and uniaxial tension tests were conducted to evaluate the hardness and plasticity of these nanolaminates, while morphologies of indentation and tensile cracks were examined with scanning electron microscope (SEM). Combined with high resolution transmission electron microscopy (HRTEM), the deformation mechanisms of Cu/CuZr nanolaminates were explored. The hardness of Cu/CuZr nanolaminates was found to be dominated by both the Cu layer and the CuZr layer. Varying the Cu layer thickness induced different size-dependent effects of the CuZr layer. For Cu/CuZr nanolaminates having the same layer thickness but different CuZr layer structures, the deformation mechanisms were closely related to the interface structure rather than the whole amorphous layer.