Mo2C particle-reinforced CuCrZr composite with enhanced wear and softening resistance

Abstract

Mo2C particle-reinforced Cu-1Cr and Cu-1Cr-0.19Zr (wt%) composites were fabricated by the powder metallurgy method. The effect of Mo2C particles on microstructure, mechanical properties, conductivity, softening resistance, and wear resistance of the composites was systematically studied. Dispersed Mo2C particles improved the properties and promoted the heterogeneous nucleation of Cr precipitates. The ultimate tensile strength, elongation, and conductivity of CuCrZr-5Mo2C (5 wt%) composite were 474.9 MPa, 33.7%, and 82.9% IACS, respectively. CuCr-5Mo2C and CuCrZr-5Mo2C composites exhibited high wear resistance and decreased friction coefficient. Cr precipitates and Mo2C particles promoted abrasive wear and reduced the wear rate. The dominant wear mechanisms of these composites were adhesion wear and abrasive wear. The average friction coefficient of CuCr-5Mo2C and CuCrZr-5Mo2C composites was 0.55 and 0.47, and the wear rate was 2.23 × 10−5 and 1.79 × 10−5 mm3·N−1·m−1, respectively. Mo2C particles effectively enhanced the high-temperature softening resistance by pinning grain boundaries. CuCr-5Mo2C and CuCrZr-5Mo2C composites' softening temperatures were 810 °C and 855 °C. These findings contribute to the development of high-performance copper composites.