Microstructure and tribological properties of ZrO2(Y2O3)–Al2O3-graphite composite ceramic fabricated by milling with graphite balls

In this study, ZrO2(Y2O3)–Al2O3-graphite composite powder was prepared by a mechanical milling method and a direct powder doping milling method, and sintered in a microwave. Microstructure and tribological properties of the composites were investigated. The results showed that uniformly dispersed fine graphite flakes were obtained using the mechanical milling method. ZrC phase was generated in the composite ceramics. The tribological properties of ZrO2(Y2O3)–Al2O3- graphite composites prepared by the mechanical milling method were better than those of ZrO2(Y2O3)–Al2O3-graphite composites prepared by the direct powder doping milling method. The friction coefficient and specific wear rate of ZrO2(Y2O3)–Al2O3-graphite composites by the mechanical milling method were 0.147 and 6.2 × 10−6 mm3/(N m), respectively. The wear mechanisms of ZrO2(Y2O3) ceramic matrix composites were discussed. •Uniformly dispersed graphite flakes was fabricated by a mechanical milling method.•The effect of the milling methods on the properties of the composites was investigated.•The wear mechanisms of the ZrO2(Y2O3) ceramic matrix composites were studied.•The ZrO2(Y2O3)–Al2O3-graphite composites possess a excellent self-lubricating effect.