Densification mechanism and corrosion properties of h-BN/MgAl2O4 ceramics prepared by hot-pressed sintering

The dense h -BN/MgAl 2 O 4 composites without additives were fabricated by hot-pressed sintering. The effect of sintering temperature and MgAl 2 O 4 on the bulk density, mechanical properties and corrosion resistance were systematically investigated. The results showed that the collaboration of sintering temperature and MgAl 2 O 4 dominated the densification behavior due to the enhanced pore filling effects and solid diffusion. The improved densification and induced microstructure development contributed to enhanced mechanical properties. Additionally, the residual MgAl 2 O 4 is more conducive to forming plate-like complex oxide with molten steel after BN oxidation and B 2 O 3 volatilization. Consequently, the plate-like complex oxide can effectively hinder direct contact between molten steel and the composite, which determines the corrosion resistance of the h -BN/MgAl 2 O 4 composite. This study highlights the enormous potential of h -BN/MgAl 2 O 4 composites for future use as side-sealing materials.