Electric Conductivity and Mechanical Properties of Carbide Dispersion-Strengthened Copper Prepared by Compocasting

Abstract

The electrical conductivity and the mechanical properties of dispersion-strengthened (DS) coppers produced by compocasting at a rotation speed of 25 s−1 with the addition of fine carbide particles in the range of 0.5 to 30 mass% WC, TaC, TiC, VC and NbC were analyzed experimentally. Homogeneous dispersion of carbide particles was observed in the microstructures of all the DS coppers containing more than 5 mass% carbide. If any carbide particle had the same size of 1 to 2 μm in the DS coppers, the Vickers hardness, Hv, was given by the following equation: Hv=53.4+3.5VP0.9, where VP was the volume percentage of carbide particles. The ultimate tensile strength of carbide particles could be evaluated using the measured ultimate tensile strength value of copper, the fractions of area occupied by copper and carbide particles, and the measured ultimate tensile strength value of DS copper. The calculated ultimate tensile strength values of WC, TaC, TiC, VC and NbC particles were 961 MPa, 539 MPa, 568 MPa, 641 MPa and 755 MPa, respectively. Similarly, the electrical conductivity of carbide particles could be also evaluated. Their calculated electrical conductivity values were in the range of the published values of electrical conductivity of the carbides.