Ex situ and in situ measurements of the shear strength of interfaces in metallic multilayers

Interfaces are generally weaker in terms of shearing and debonding in comparison to perfect grains since atoms within interfaces usually have low coordination bonds. In this letter, we report the experimental measurements of the shear strength of Cu–Nb interfaces by using quantitative ex situ and in situ indentations. The interface shear strength is estimated from experiments in the range of 0.3–0.55 GPa, which is consistent with atomistic simulations and evidence of the weak interface strengthening mechanisms in metallic multilayers.