Preparation of Ca-α SiAlON powder by reduction-nitridation in a gas mixture of C<sub>3</sub>H<sub>8</sub> and NH<sub>3</sub>

Abstract

Ca-α SiAlON powders were synthesized from a SiO2–Al2O3–CaCO3 powder mixture by reduction-nitridation with C3H8–NH3 gas. Ca-α SiAlON with small amounts of AlN and β-SiAlON phases was produced at 1450°C for 120 min. Angular particles and agglomerated and bonded particles with irregular shapes were formed. In the product prepared at 1450°C without any holding time, Si2N2O was detected as an intermediate phase, in addition to the Ca-α SiAlON, β-SiAlON and AlN phases. A large number of agglomerated and bonded particles were observed.