Preparation and tribological properties of Ti₃SiC₂/Cu composites

The Ti₃SiC₂/Cu composites were prepared by spark plasma sintering (SPS) process using Ti₃SiC₂ ceramic powder and Cu powder as raw materials. The effect of content of Ti₃SiC₂ and sintering temperature on the microstructure, relative density and hardness of Ti₃SiC₂/Cu composites were investigated, and the friction and wear properties of the Ti₃SiC₂/Cu composites after SPS were also studied. The results show that Ti₃SiC₂ are evenly distributed in Cu matrix for the Ti₃SiC₂/Cu composites prepared by SPS process. But with the increase of Ti₃SiC₂ content and sintering temperature, agglomeration trend appears in the tissue, and some Ti₃SiC₂ and Cu miscibility at the interface enhances the ability to bind to the matrix. The Ti₃SiC₂ content and sintering temperature have a great influence on the density and microhardness of the Ti₃SiC₂/Cu composites. When the sintering temperature is 900℃, the density of the Ti₃SiC₂/Cu composites reaches 99.7%, which is close to complete density. The hardness of the Ti₃SiC₂/Cu composites is about 2 times higher than that of pure Cu. The wear mechanism of Ti₃SiC₂/Cu composites with different Ti₃SiC₂ contents is also different. When the content of Ti₃SiC₂is low (1vol%–5vol%), the wear mechanism is abrasive wear and adhesive wear. With the increase of Ti₃SiC₂ content (10vol%–15vol%), it gives play to its self-lubricity, the friction and wear properties of the Ti₃SiC₂/Cu composites are improved, and the wear mechanism is changed to plough cutting and slight adhesive wear. With the content of Ti₃SiC₂ further increases to 20vol%, the wear surface becomes uniform and flat, indicating that the wear resistance of the Ti₃SiC₂/Cu composites is enhanced.