Review on the properties of hexagonal boron nitride matrix composite ceramics

Novel hexagonal boron nitride (h-BN) matrix composite ceramics exhibit versatile and greatly improved properties compared with the traditional h-BN ceramics, such as excellent mechanical properties, high-temperature resistance, thermal shock resistance, ablation resistance, and molten metal erosion resistance. They have potential important applications in the field of aerospace, electronics, metallurgy, machinery, nuclear energy, etc. As such, much attention are paid by both academia and industry on materials science and technology. In this paper, the special crystal structure and unique characteristics of h-BN are firstly briefly introduced. Then, the state-of-the-art development on mechanical properties, thermal shock resistance, ablation resistance, ion erosion resistances, molten metal erosion resistance and the damage mechanisms of novel h-BN matrix composite ceramics under harsh serving environments are reviewed, including textured h-BN matrix composite ceramics with anisotropic properties targeted for heat management applications. Moreover, the possible future research focus on h-BN and h-BN matrix composite ceramics are also forecasted.