Research and application progress of hexagonal boron nitride (h-BN) based composite ceramics

Hexagonal boron nitride (h-BN) based composite ceramics present excellent mechanical properties, high-temperature resistance, thermal shock resistance, ablation resistance, dielectric and electromagnetic wave transparency performance, molten metal erosion resistance, machinability, etc. Furthermore, the flake-shaped grains of h-BN can be arranged parallel to form textured structure, which can be endowed with obviously anisotropic properties. So h-BN based composite ceramics have found many important applications in the field of aerospace, electronics, metallurgy, machinery, energy, etc., thus much attention is paid by both industry and academia on materials science and technology. At present, h-BN based composite ceramics have been successfully applied as multi-functional heat resistance components and high-temperature structure components used in harsh environments, such as high-temperature antenna window cover plate of spacecraft, ion channel components of Hall thruster, side sealing plates for thin roll strip continuous caster. In this paper, recent progress of preparation process, performance characteristics and damage mechanisms, application of h-BN based composite ceramics are systematically summarized and reviewed. At the end, their relevant research and development direction in the future are prospected.