Tribological performance and surface morphological analysis of in-situ synthesized BN-Si₃N₄ reinforced SiC-Al₂O₃ ceramic matrix composites

A new kind of multi-phase ceramic composite comprising of a SiC matrix reinforced with Si₃N₄ and BN was prepared by in-situ formation during nitridation of Si metal and B₂O₃. Al₂O₃ was used as a sintering additive as well as to improve oxidation and corrosion resistance. XRD and SEM techniques were effectively utilized to confirm phases and analyse the evolutionary changes in microstructure. Dry wear tests were conducted to evaluate the composite's wear resistance. It was discovered that the SiC-Si₃N₄–BN–Al₂O₃ composite possessed exceptional properties, such as high hardness, high abrasive wear resistance, and low coefficient of friction. The examination of surface topography using atomic force microscopy indicates that the composites exhibit improved smoothness and enhanced capacity for load bearing. These characteristics make the composite material highly promising for diverse tribological applications. Furthermore, the strengthening and wear mechanisms of this composite were analysed and discussed in this paper.