Effect of heat treatment on the microstructure and mechanical properties of copper/SS304L composite sheets.

Different annealing treatments at 400-900 °C for 1 h were applied on copper/SS304L composite sheets, and the evolutions of microstructure and mechanical properties were investigated in this study. It is found that the diffusion distance of the elements at the interface is slightly increased with the increasing temperature. In addition, the grain coarsening in copper, the phase transformation from BCC to FCC in SS304L, and the decreased dislocation density after annealing soften the composite sheets, leading to decreased hardness and strength, as well as significantly improved ductility, especially when the temperature exceeds 500 °C. • Different heat treatments at 400–900 °C were applied on Cu/SS304L composite sheets. • Diffusion at the interfaces is promoted with the increase of annealing temperature. • Microstructure transforms from BCC to FCC in the SS304L sides after annealing. • Microhardness of the composites decreases as annealing temperature increases. • The strength decreases and the ductility increases as temperature exceeds 500 °C. [ABSTRACT FROM AUTHOR]