Strength and ductility synergy in a laminated Cu/Cu-6Al alloy with graded interfacial region

Abstract

The “trade-off” between strength and ductility of structural materials has been the subject of research for a long time. Designing heterogeneous structures is considered to be a promising and suitable strategy to improve the mechanical properties, including both the strength and ductility. In this work, we fabricated a laminated Cu/Cu-6Al alloy by powder metallurgy technique. The laminated Cu/Cu-6Al alloy possesses a graded interfacial region with the width of ~50 µm due to the diffusion of elements during sintering and hot rolling. The graded interfacial structure can effectively relieve the stress concentration at the interface by coordinating multiple deformation mechanisms from dislocation activity to deformation twinning, and thus provide continues working hardening ability. The laminated Cu/Cu-6Al alloy possesses a combination of high strength and large ductility. This work provides a new concept to design high-performance structural materials by forming graded interfaces.