Enhanced strength and electrical conductivity of Cu-Zr-B alloy by double deformation-aging process

The microstructures, mechanical/electrical properties and precipitation behaviors of Cu-Zr-B alloy manufactured by double deformation-aging process were investigated. The results show that an excellent balance of tensile strength and electrical conductivity, e.g. as high as 575.4 MPa and 79.37% IACS, respectively, can be obtained for the alloy after primary 80% cold rolling and aging at 470 degrees C for 2 h followed by secondary 40% cold rolling and aging at 360 degrees C for 2 h. The achievement of such high strength and electrical conductivity can be attributed to the interactions of strain hardening and precipitation behaviors taking place in the course of double deformation and aging treatments. High softening resistance is the outgrowth of the occurrence of limited recovery and recrystallization. After secondary deformation and aging, discontinuous precipitation can be suppressed but continuous one promoted. It is found that the precipitates responsible for strengthening are fcc structure Cu5Zr with the orientation relationship of (10 (1) over bar)(M)//(2 (1) over bar(1) over bar)(P) and [111](M)//[111]. (C) 2014 Elsevier B.V. All rights reserved.