Strength and strain hardening behavior of Cu-based bilayers and trilayers

Strain hardening in metallic multilayers is shown experimentally to be greater in trilayer films of Cu-Ni-Nb than bilayer films of Cu-Ni or Cu-Nb using both direct measurements of flow strength at different effective strains and an analysis of the out-of-plane deformation around nanoindentation impressions. The mechanism that accounts for increased strain hardening in the trilayer is a proposed super-threader dislocation and cross-slip mechanism, modeled using three-dimensional dislocation dynamics simulations. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.