On interface strengthening ability in metallic multilayers

The strength of Cu/Au multilayers with different individual layer thicknesses (λ) from 25 to 250 nm has been investigated by nanoindentation testing. It is found that the increase in strength of the Cu/Au multilayers with decreasing λ follows the Hall–Petch relation until λ is less than 50 nm. Based on the concept of lattice mismatch, a simple model is proposed to describe interface strengthening ability in metallic multilayers found here and reported in the literature.