Effects of feature sizes on Cu/CoCrFeNi polycrystalline metallic multilayers

T Fu and CY Li and XL Li and H Hu and XH Peng, JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T, 36, 8179-8190 (2025).

DOI: 10.1016/j.jmrt.2025.05.084

The mechanical properties of metal nanolaminates are strongly affected by feature size (the thickness of individual layer, h, and in-plane grain size, d), as well as their interplay. In this work, we comparatively investigated the effects of hand d on the mechanical properties of Cu/CoCrFeNi nanolayered polycrystalline metal multilayers (NPMMs) under uniaxial compression using molecular dynamics simulations. The results showed that reducing h significantly increases the flow stress of NPMMs. In contrast, the effect of decreasing d on flow stress depends on h: for smaller (1-2 nm) and larger (5-10 nm) h, the flow stress increases and then decreases with decreasing d; while for moderate h (2-5 nm), d has an insignificant effect on the flow stress. This indicates a pronounced coupling effect between d and h. Furthermore, the exploration of the deformation mechanisms of the coherent twin Cu/CoCrFeNi NPMMs and the coupling effect also showed that: for larger and smaller h, grain boundaries exhibit a strong hindering effect on dislocation motion; while for moderate h, such hindering effect is weak. Based on the confined layer slip theory, interface barrier strength model, Hall-Petch and Inverse Hall-Petch models, a theoretical model was suggested for quantitatively describing the flow stress of coherent twin Cu/ CoCrFeNi NPMMs with different d and h. The results presented would be of great significance for the development of Cu/HEA nanolaminates.

Return to Publications page