Corrosion Resistance of β-SiAlON Nano Ceramics

Abstract

β-SiAlON nano ceramics were fabricated by spark plasma sintering using the ultra fine powder synthesized through carbothermal reduction-nitridation method, and its aqueous and gas corrosion resistance were evaluated. As a result of TEM observation,the developed β-SiAlON ceramics were composed of nano-sized grains and the glassy phase was hardly found at the grain boundary. It showed much higher aqueous corrosion resistance than commercialized Si₃N₄ceramics. Furthermore, the βSiAlON nano ceramics possessed high corrosion resistance to air and air-SO_xgas mixture at high temperature. It is considered that the improvement of these properties resulted from not only excellent thermal and chemical durability of βSiAlON but also very little glassy phase in their grain boundary.