Preparation of SPS-ed Al<sub>2</sub>O<sub>3</sub>-TiC-Ti<sub>3</sub>SiC<sub>2</sub> Composites Using Elemental Powders, and their Wear and Cutting Behaviors

All composite materials with Al2O3 as the matrix, TiC as the reinforcing phase, and Ti3SiC2 as the lubricating phase were synthesized in this study. The composites were prepared by using the in-situ reaction of the raw powders of Ti, Si, graphite, Al and Al2O3 through spark sintering technology. Three peaks for both Al2O3-TiC-10 and 20 vol% Ti3SiC2, in densification rate curves corresponded to plastic deformation and power law creep deformation of Al2O3, Ti3SiC2 and TiC, respectively. The Al2O3-TiC-10, 20 vol%Ti3SiC2 compacts showed homogeneously localized Ti3SiC2 as a lubricating phase between the TiC and Al2O3 hard phases. Pin-on-disc friction and wear tests on Al2O3-TiC-0, 10, 20 vol%Ti3SiC2/ Ti-6Al-4V combinations revealed that the introduction of Ti3SiC2 phase could effectively improve the damage morphology of the worn surface, and the optimal wear resistance was exhibited when the content was 20 vol%. Al2O3-TiC-20 vol%Ti3SiC2 tool exhibited superior intermittent cutting performance to WC-7Co tools, particularly in terms of wear resistance and tool life. Judging from the Hv, KIC, cutting and friction-wear properties, it may be believed that Al2O3-TiC-20 vol%Ti3SiC2 compact is replace candidate for the WC-7Co under the rare metal element strategy.