Electrical Conductivity of Ultrafine-Grained Cu and Al Alloys: Attaining the Best Compromise with Mechanical Properties

Abstract

In recent years, the severe plastic deformation community has developed an interest for metallic materials with high strength and high electrical conductivity, with special focus in Cu- and Al-based alloys, including composite materials. Several processing and metallurgical strategies have been applied to control the influence of microstructure features such as grain refinement, grain boundary condition, defect structures and segregation of secondary phases, over the electrical and mechanical properties. This work summarizes an important body of literature where several strengthening mechanisms and methods to restore the electrical conductivity have been applied to produce ultrafine-grained or nanostructured Cu and Al alloys, mainly by intense imposed strain. A wide variety of alloy systems were studied for their industrial applications in the electrical and electronic market. It can be concluded that the balanced combination of alloying element selection and processing route (mainly attainable under high hydrostatic conditions) could provide high strength with high conductivity and thermal stability materials.