Construction of a dual heterogeneous lamella structure to improve the electrical conductivity and mechanical properties of Cu alloys

Copper (Cu) based materials desire superior mechanical properties and high conductivity for potential industry application. In this work, a specially designed dual heterogeneous lamella structure (DHLS) was produced in Cu alloy by powder metallurgy and deformation heat treatment. It is characterized by soft micrograined lamellae embedded inside a hard matrix of ultrafine grains containing nano-sized precipitations. Such dramatic microstructure heterogeneities produce strong back stress hardening, which led to substantially improved ultimate tensile strength (530.5 MPa) without greatly sacrificing the original ductility. In addition, the recrystallization of micrograined lamellae and the aging precipitation of ultrafine grains result in the high conductivity. This study offers a workable strategy to using DHLS to optimize the comprehensive Cu-based materials with an excellent strength-electrical conductivity combination.