Synthesis and characterization of boron nitride reinforced alumina ceramic composites

Alumina-based composites (Al₂O₃) exhibit excellent mechanical and electrical properties. Incorporation of boron nitride (BN) further enhances these attributes, making them suitable for aerospace and automotive applications. The improved mechanical strength of these composites at high temperatures is a key attribute. The addition of BN significantly improves the heat resistance of alumina ceramics, making them well-suited for engine components and cutting tools that operate under extreme conditions. Beyond their mechanical benefits, Al₂O₃-BN composites excel as electrical insulators, with BN enhancing the material's resistance to electrical conductivity, making them a preferred choice for high-voltage and insulation applications. Ongoing research underscores the potential of these materials in future technological advancements. Experimental investigations show that varying BN content between 0 and 1 wt% results in mechanical property changes. These are supported by experimental stress-strain curves included in the results section. These composites, compacted via hydraulic pressing and sintered in an argon atmosphere at 1600 °C for 4 h, exhibit density improvements from 98.6 % to 99.3 % as BN concentration increases. The optimal BN content of 0.5 wt% yields peak performance, achieving a flexural strength of 424 MPa (an improvement of 3.41 %) and fracture resistance of 6.3 MPa·m¹/² (a 34.04 % enhancement). Additionally, Al₂O₃-BN composites demonstrate impressive wear resistance and reduced friction. A BN content of 0.25 wt% lowers wear rates and reduces the coefficient of friction (COF) by 46.11 % at room temperature and 61.30 % at elevated temperatures. To maintain these advantages, it is crucial to keep the BN content below 0.5 wt%, ensuring the optimal balance of mechanical, thermal, and tribological properties for high-performance applications.