Composition and microstructure of nanosized, amorphous and crystalline silicon nitride powders before, during and after densification

Abstract

The composition, microstructure and densification behaviour of two amorphous and three crystalline silicon nitride powders containing an MgO–Y₂O₃ sintering aid have been investigated. The powders were characterised in terms of bulk and surface chemical compositions, crystallinity and morphology. The hot-pressing behaviours of the powders were assessed by considering the mass losses on densification, relative densities and the chemical and phase compositions and microstructure of the dense materials. Densification kinetics were analysed by the computer evaluation of hot-pressing data.