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

In this study, we investigated the influence of Cr2O3 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 Cr2O3 had a negative effect on the formation of mullite. As the Cr2O3 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 Cr2O3 on the formation and growth of mullite can be mitigated by mechanochemically activating the precursor mixture via high-energy ball milling.