Performance and characterization of dispersion strengthened Cu-TiB2 composite for electrical use

New copper-based composites are developed via powder metallurgy and strengthened through the dispersion of ceramics. The preparation of these alloys is carried out in two stages: (a) mechanical alloying (MA) in a planetary mill of high energy and (b) consolidation by hot uniaxial pressure followed by hot rolling. The behavior of the mechanical and electrical properties of these alloys associated to the inicrostructure changes will determine if the desired characteristics are achieved, for their use in electrical components. In the present study two copper-based alloys with 1% vol and 2% vol TiB2 were made by mechanical alloying over 12 h and 36 h. The resulting compacts consist mostly of equi-axed TiB2 grains homogeneously dispersed in a copper matrix with an average diameter of 0.6 mu m for the 36 It sample. The consolidated composites have an electrical conductivity of 31.4% IACS (International Annealed Copper Standard, 100% IACS=58 MS/m), a hardness of 78.7 HRb, and a tensile strength of 318 MPa as a minimum. Moreover, the TiB2 shows good stability at 923 K during hot consolidation. (c) 2005 Elsevier Inc. All rights reserved.