Size-dependent hardness and tensile plasticity of Ta-Zr 61 Cu 17.5 Ni 10 Al l7.5 Si 4 nanolaminates

Abstract

Abstract Ta/Zr 61 Cu 17.5 Ni 10 A l7.5 Si 4 crystalline/amorphous (C/A) nanolaminates with different Ta and ZrCuNiAlSi layer thicknesses were deposited by magnetron sputtering on both Si and polyimide substrates. Nanoindentation and uniaxial tensile tests were separately performed to study their size-dependent hardness and plasticity. Tensile plasticity was evaluated by considering both the tensile cracks and nanoindentation morphologies observed under scanning electron microscope (SEM). C/A nanolaminates with crystalline layer thickness of 40 nm and amorphous layer thickness of 5 nm exhibited the best tensile plasticity, which was much better than pure Ta and Zr 61 Cu 17.5 Ni 10 A l7.5 Si 4 monolayers. For nanolaminates having identical Ta layer thickness, the hardness always increased with decreasing amorphous layer thickness. Combined with cross-sectional high resolution transmission electron microscopy (HRTEM) observation, the size-dependent deformation mechanisms of C/A nanolaminates were discussed.