Papers by Keyword: Yb α-SiAlON

Abstract: In this paper, Yb a-sialon powders with elongated grains have been prepared by combustion synthesis. The effects of diluents, nitrogen pressure, adding a-sialon seeds and NH4F on the phase transformation and microstructure development of the samples are discussed systematically. The experimental results show that the addition of diluents, proper nitrogen pressure and additive NH4F can facilitate the nitridation of Si. It was also found that the added a-sialon seeds and NH4F are beneficial to the nucleation and growth of elongated grains.

Abstract: In this paper, single-phase Yb α-SiAlON ceramics were prepared by pressureless sintering and the densification, phase transformation as well as microstructure development were studied. It was demonstrated that the phase transformation could be completed at 1700 °C and elevated temperature was beneficial to grain growth. Additionally, effect of the addition of seed crystals prepared by combustion synthesis was discussed. From the experimental results, it was found that the added seed crystals facilitated the phase transformation and improved the microstructure development, resulting in the formation of elongated grains.