Phase formation and microstructure evolution in mullite ceramics synthesized from mechanochemically activated oxide powders doped with Cr2O3

Abstract In this study, we investigated the influence of Cr 2 O 3 on phase formation and microstructure evolution in mullite ceramics. We also explored the mechanochemical effects of high-energy milling with stainless steel and tungsten carbide. X-ray diffraction and scanning electronic microscopy analyses showed that the introduction of Cr 2 O 3 had a negative effect on the formation of mullite. As the Cr 2 O 3 content increased from 5 mol% to 20 mol%, the initial formation temperature for mullite increased from 1300 °C to 1500 °C. The negative effect of Cr 2 O 3 on the formation and growth of mullite can be mitigated by mechanochemically activating the precursor mixture via high-energy ball milling.