Enhanced mechanical and electrical properties of in situ synthesized nano-tungsten dispersion-strengthened copper alloy

Abstract

In this study, a novel dispersion-strengthened copper-tungsten alloy with improved mechanical properties, electrical conductivity, and thermal stability was prepared by mechanical alloying. Cu-WO3 powder blend was milled to obtain a uniform dispersion of WO3 in copper and the WO3 particles were subsequently reduced to tungsten to obtain the Cu–W composite. The tungsten nanoparticles dispersed in the copper matrix have an average size of 32 nm, without agglomeration, and are highly stable. The cold-rolled Cu-5 vol% W reached a tensile strength of 596 MPa, elongation of 7.7%, and electrical conductivity of 84% IACS (International annealing copper standard). In particular, the cold-rolled alloy retains the tensile strength of over 400 MPa and reasonable ductility even after annealing at 800 °C. The remarkable improvement in mechanical properties and thermal stability are attributed to the pinning effect of highly dispersed nano-sized W particles in the Cu matrix.