Fabrication of (Ca + Yb)- and (Ca + Sr)-stabilized α-SiAlON by combustion synthesis

In this paper, (Ca + Yb)- and (Ca + Sr)-stabilized α-SiAlON powders were fabricated by combustion synthesis. The influence of Ca2+ incorporation on the phase composition and grain morphology of combustion products was discussed. The experimental results showed that with the incorporation of Ca2+ well-developed rod-like (Ca + Yb) α-SiAlON crystals could be produced. It was also found that, when only Sr2+ was used as stabilizing cation, the reaction product was (α + β)-SiAlON composite, in which β-SiAlON was the predominant phase and the relative content of α-SiAlON was low. With the incorporation of Ca2+, however, both the relative content and the lattice parameters of α-SiAlON were clearly increased. These results indicated that the incorporation of Ca2+ could assist Sr2+ into the α-SiAlON lattice structure.