Anisotropic grain growth in mullite was investigated in B2O3-doped diphasic gels seeded with either mullite particles or whiskers. Anisotropic grain growth was observed in all systems. The largest anisotropic grains were obtained with a system seeded with 2 wt% mullite whiskers and doped with 2 wt% B2O3. The mullite whiskers act as sites for multiple nucleation and subsequently as templates for mullite overgrowth. Boria lowered the mullite formation temperature by 150° C and it significantly enhanced anisotropic grain growth independent of the presence of seed particles. This enhancement was attributed to increased dissolution of alumina.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry