Mechanical properties of Cu/Cu-Al laminated alloys with gradient interface affected zone

In this work, four types of laminated Cu-Al alloys with the same total thickness but varying numbers of layers were fabricated using a combination of powder metallurgy and hot rolling techniques. Due to the element diffusion caused by sintering and hot rolling, a gradient interface region, also called interface affected zone (IAZ), with a width of about 70-110 mu m was formed between the Cu layer and the Cu-6Al layer. The results suggest that compared to the homogeneously mixed Cu/Cu-6Al alloy, the laminated alloy exhibits higher mechanical properties. Especially, the laminated alloy with more layers and smaller interface spacing shows superior mechanical properties. The IAZ can effectively relieve the stress concentration at the interface and thus provide continuous work hardening ability. Furthermore, the heterogeneous deformation-induced (HDI) strengthening was enhanced by adjusting the interface spacing and the width of the IAZ, so as to achieve a synergistic enhancement of strength and ductility.