Mullitization in Al2O3-SiC nanocomposite: A case study of high temperature oxidation

Alumina-SiC nanocomposites, which offer a better mechanical performance than conventional ceramic materials, are a class of potentially important structural materials. Unfortunately, alumina-SiC nanocomposite is a thermodynamically metastable system at elevated temperatures. The SiC particles, especially those near the sample surface, are susceptible to oxidation at temperatures above 1,000 C, forming silica which may subsequently react with the alumina matrix. The objective of the present work is to investigate the mullitization reaction between the oxidation-led nano-silica particles and alumina matrix in an alumina-5 vol% SiC nanocomposite