Optimisation of strength and ductility of Cu–Cr–Zr by combining severe plastic deformation and precipitation

The microstructure and mechanical behaviour of a Cu–Cr–Zr alloy has been examined after severe plastic deformation, and giving both prior and subsequent age hardening treatments. Dislocation subgrain structures are produced by deformation leading to high strength and reduced ductility. Mild annealing following deformation leads to slight substructural coarsening, some loss of dislocations, and simultaneous precipitation, resulting in an increase of strength with some improvement of ductility. The same heat treatments for precipitation before deformation lead to finer substructures, with shear reducing particle size and leading to partial dissolution. Strength and ductility are analysed in terms of the deformation substructures and the role of precipitate particles.

► ECAP of Cu–Cr–Zr has been carried out with both prior and posterior heat treatments.
► Heavy deformation leads to fine subgrain structures producing boundary strengthening.
► Annealing following deformation leads to increases of both strength and ductility.
► Ageing before deformation leads to more refined substructures and higher strength.