The present study provides an overview of the fabrication of silicon nitride (Si3N4)-based advanced ceramic materials using spark plasma sintering. Being an excellent engineering ceramic material, silicon nitride is extensively being used in tribological components, aerospace, and automotive industries due to its unique blend of thermo-mechanical, tribological, and chemical properties. The selection of the sintering process, as well as sintering aids, strongly affects the properties of silicon nitride ceramics. Several conventional sintering techniques have been utilized in the past to optimize the structure and properties of silicon nitride ceramics such as hot pressing. However, spark plasma sintering, a relatively new, non-conventional, powder consolidating technique has recently gained significant attention to fabricate silicon nitride ceramic due to high heating rates, extremely short sintering time, and relatively low sintering temperatures which renders it an ideal technique for mass production. Both the composition and concentration of sintering additives during processing play a vital part in achieving the final desired properties of the bulk silicon nitride ceramic materials. In this review, the critical aspects like the effects of additive composition, additive concentration, and sintering parameters on microstructure and bulk properties of silicon nitride ceramics fabricated via spark plasma sintering are presented. The review may come in handy for scientists and engineers concerned with fabricating future silicon nitride composites with desired properties and performance for different engineering applications.
Spark plasma sintering-densified vanadinite apatite-based chlorine waste forms with high thermal stability and chlorine confinement