Evolution of microstructure and property alterations in Cu-Ag-Cr alloy under rolling deformation

Abstract

The mechanical strength of Cu-Ag alloys can be enhanced while preserving their electrical conductivity through the addition of a third alloying element and deformation processing. This study examines the microstructural evolution of Cu-Ag and Cu-Ag-Cr alloys following cold rolling, quantifying the effects of grain boundaries, dislocations, solid solutions, and Ag precipitates on strengthening mechanisms, as well as describing the alloy's conductive behavior. The incorporation of Cr alters the precipitation behavior in Cu-Ag, promoting a predominantly continuous Ag precipitate phase. Cr addition results in a significant improvement in mechanical properties, leading to an increase in strength by approximately 140–160 MPa compared to Cr-free Cu-Ag alloys. The difference in strength between the two alloys is primarily attributed to variations in the evolution of precipitate phases at different levels of deformation, driven by a combination of dislocation and precipitation strengthening mechanisms. The reduction in electrical conductivity is mainly attributed to enhanced interfacial scattering following rolling deformation.