High-Temperature Oxidation of Nickel-Dispersed Mullite Composites in Air

Abstract

High-temperature oxidation of 5 vol% Ni dispersed mullite-based composites was investigated at temperatures ranging from 1200 to 1400℃ for 1 to 48 h in air. Oxidation behavior at high temperatures of Ni/mullite composites was compared with other ceramic-based composites and then discussed in the present paper. Oxidation of Ni particles within mullite matrix developed a surface layer of the oxidation products and an internally oxidized zone. Growth of the internally oxidized zone obeyed the parabolic law, which meant diffusion process in internally oxidized zone is the rate controlling process. Comparison in this investigation indicated that Ni/mullite has a greater oxidation resistance than these of reported composites such as Ni/MgO and Ni/Al₂O₃.