Effect of WC Addition on the Wear Resistance of Mullite-WC Composites Sintered by Spark Plasma Sintering

This study aims to improve the wear resistance of mullite ceramics as one of the most critical engineering ceramics by adding tungsten carbide (WC) particles. For this purpose, mullite-WC composites without and with adding 5, 10, and 15 % by weight of WC particles produced by Spark Plasma Sintering (SPS) method. In addition, it investigates the effect of sintering temperature on the wear resistance of mullite-WC composites applied by the SPS process at 1300 °C, 1350 °C, 1400 °C, and 1450 °C for 4 minutes under the pressure of 30 MPa. The results pin on the disk testing indicates that upon increasing the weight percentage of WC particles and increasing the sintering temperature up to 1400 °C, the wear resistance of mullite-WC composites would increase. However, increasing the sintering temperature up to the range of 1450 °C led to a decrease in the wear resistance due to the poor mechanical properties and formation of the W2C phase. The results from Scanning Electron Microscopy (FESEM) analysis are indicative of the formation of abrasive wear and surface layer structure mechanisms on the surface in mullite ceramics samples with and without WC reinforcing particles.