Study on the microstructure and properties of dispersion-reinforced Cu-based composites by ultrafine WC and nano-sized Al₂O₃ particles via extrusion densification

The dispersion-reinforced Cu-based composites by ultrafine WC and nano-sized Al₂O₃ particles (WC-Al₂O₃/Cu)were obtained by hot extrusion densification using the nano-sized Al₂O₃ particles, ultrafine WC powders, and industrial pure copper powders as raw materials. The microstructures and performances of the extruded WC-Al₂O₃/Cu composites were investigated. In the results, the relative density of the 5%WC-2%Al₂O₃/Cu and 10%WC-2%Al₂O₃/Cu composites by mass is over99% after mechanical milling, cold pressing, vacuum sintering, and hot extrusion. At this meantime, the ultrafine WC and nano-sized Al₂O₃ particles distribute homogenously in the Cu matrix, resulting in high mechanical strength and excellent electrical conductivity. The tensile strength, elongation, and electrical conductivity of 5%WC-2%Al₂O₃/Cu composites are 235.06 MPa, 15.47%, and 85.28% IACS, respectively, and the softening temperature is above 900℃, showing a better comprehensive performances.