Silicon Nitride Ceramics Strengthened by In-Situ Precipitation of TiN

Abstract

Si₃N₄ is one of the mostattractive materials for wear applications. Some of the authors have beeninvolved in the creation and development of this material as a pioneer researcher. At present, a high-quality Si₃N₄ ceramic foruse as wear components has been fabricated from the system Si₃N₄-Y₂O₃-Al₂O₃-TiO₂-AlN,but the sintering behavior was not clear. Thus we have investigated the effectof adding TiO₂ and AlN on the densification and microstructure development in the above system. As a result, we found the TiO₂ promoted the densification changing into TiN, which was precipitated betweenthe grain boundary as isotropic grains. Strengthening effect of the dispersion of TiN grains was discussed by microstructural analysis and contact damage testing method.