Effects of Cr₂AlC content on friction and wear properties of copper matrix composites

The copper matrix composites with Cr₂AlC in the mass fraction of 0%, 5%, 10%, and 15% were prepared by cold pressing-sintering method.The microstructures and compositions of the composites were studied by optical microscope (OM), scanning electron microscope (SEM), and energy disperse spectroscope (EDS).The hardness and the properties of friction and wear of the composites were tested on HVS-1000 microhardness tester and M-2000 friction and wear tester.The effects of Cr₂AlC contents by mass on the hardness, friction property, and wear mechanism of the composites were analyzed.The results show that, the relative density of copper matrix composites with Cr₂AlC is 0.8, the Cr₂AlC evenly distributes on the copper matrix and effectively improves the composites hardness.With the increase of Cr₂AlC content, the friction coefficient of the composites increases first and then decreases, and the abrasion loss decreases first and then increases.When Cr₂AlC content by mass is 10%, the friction coefficient is the largest, the wear rate is the lowest, and the wear resistance is the best.The wear mechanism of pure copper without Cr₂AlC is mainly stick slip, and the wear form of copper matrix composites with Cr₂AlC is the combination of plough wear, stripping wear, and oxidation wear.