Pulsed electric current sintering of TiB2-based ceramics using nitride additives

Abstract

In this research, various types of nitride additives were incorporated into titanium diboride attaining dense TiB₂-based ceramics by field-assisted sintering technique. The addition of different types of nitride additives, namely Si₃N₄, BN, AlN, and TiN, significantly improved the sinterability of TiB₂, achieving near fully dense ceramics. The X-ray diffraction analysis and microstructural evaluation confirmed the presence of the h-BN compound in all specimens. In the TiB₂-Si₃N₄ ceramic, Si₃N₄ additive reacted with B₂O₃ oxide, in-situ generating h-BN, and SiO₂ phases. Although the h-BN phase was produced in the TiB₂-AlN specimen, the main proportion of AlN remained in the sample as an unreacted ex-situ phase. In terms of the TiB₂-TiN ceramic, some of the nitrogen and boron atoms could leave the TiN and TiB₂ crystalline structures, contributing to the in-situ formation of h-BN.