Pulsed electric current sintering of TiB۲-based ceramics using nitride additives

In this research, various types of nitride additives were incorporated into titanium diboride attaining dense TiB۲-based ceramics by field-assisted sintering technique. The addition of different types of nitride additives, namely Si۳N۴, BN, AlN, and TiN, significantly improved the sinterability of TiB۲, 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 TiB۲-Si۳N۴ ceramic, Si۳N۴ additive reacted with B۲O۳ oxide, in-situ generating h-BN, and SiO۲ phases. Although the h-BN phase was produced in the TiB۲-AlN specimen, the main proportion of AlN remained in the sample as an unreacted ex-situ phase. In terms of the TiB۲-TiN ceramic, some of the nitrogen and boron atoms could leave the TiN and TiB۲ crystalline structures, contributing to the in-situ formation of h-BN.

Keywords:

Titanium diboride , Silicon nitride , Hexagonal boron nitride , Aluminum nitride , Titanium nitride , Field assisted sintering technique