Preparation of Ca-α SiAlON hollow spheres by carbothermal reduction–nitridation of CaO–Al 2O 3–SiO 2 glass

Abstract

Ca-α SiAlON powders were prepared by carbothermal reduction–nitridation of CaO–Al 2O 3–SiO 2 glasses at 1450 °C for 2 h in nitrogen. The content of Ca-α SiAlON phase was 65–81% in the products, and the other phases were AlN and β-SiAlON. The products contained hollow spheres with the size of around 5 μm in diameter. The particle morphology was almost identical to that of Ca-α SiAlON prepared from CaCO 3–Al 2O 3–SiO 2 powder mixtures.