A hard/soft layered micro-structured CuCrZr alloy with strength, ductility and electrical conductivity synergy

Layered CuCrZr alloys with different hardness ratios of heterogeneous hard/soft microstructures were prepared by powder metallurgy combined with rolling and annealing. The alternating hard/soft microstructure with a reasonable high hardness ratio tends to produce bigger Bauschinger effect and higher hetero-deformation induced (HDI) stress during non-uniform deformation, which helps the layered CuCrZr alloy to obtain excellent combination of strength, ductility and electrical conductivity. The high strength and high ductility are attributed to the high HDI stress and high HDI hardening produced by heterogeneous hard/soft microstructure during plastic deformation. Moreover, the soft Cu layer with relatively high electrical conductivity improves the electrical conductivity of layered CuCrZr alloys. This work on layered structure design with a reasonable high hardness ratio of hard/soft microstructure provides an effective method to solve the trade-off between strength, ductility and electrical conductivity of copper alloys.