Influence of Additive Type on Densification and Phase Transformation of Seeded Si3N4
This paper deals with densification and a®b phase transformation of Si3N4, with a constant b-Si3N4 seeds concentration regarding sintering temperature and different additive types. The seeds of b-Si3N4 were obtained by sintering of silicon nitride in a-form and additive mixture consisting of Y2O3 and SiO2. Two different Si3N4/additive mixtures (Y2O3 + Al2O3 and CeO2) containing constant amount of seeds were prepared and tested. Characterization of sintered samples involved phase analysis by X−ray diffraction and density measurements. The results indicated that in the presence of yttria-alumina mixture both the phase transformation and the densification were enhanced as compared to samples containing only CeO2 as a sintering additive. The reasons for observed behavior are discussed in detail.
Dragan P. Uskokovic, Slobodan K. Milonjic, Djan I. Rakovic
A. Vučković et al., "Influence of Additive Type on Densification and Phase Transformation of Seeded Si3N4", Materials Science Forum, Vol. 494, pp. 429-434, 2005