The effect of coherent interface on strain-rate sensitivity of highly textured Cu/Ni and Cu/V multilayers

The strain-rate sensitivity (SRS) depends on the evolution of applied shear stress and dislocation activation volume. Quantifying SRS at different grain sizes is important to understand thermally activated plastic deformation. Here we present SRS studies of highly textured Cu/Ni and Cu/V multilayers with individual layer thickness (h) varying from 1 to 100 nm. When h > 10 nm, the SRS of Cu/Ni multilayers increases with decreasing h, but the opposite holds when h < 10 nm due to the formation of coherent interface. In comparison, the SRS of Cu/V multi layers keeps unchanged when h < 10 nm. Our findings provide more insight to understand the size-dependent deformation mechanisms in multilayers. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.