Microstructure and Mechanical Properties of Mullite Composites via Pressure Molding and by Oxidation of an Al-Si Alloy Powder
A novel technique to synthesize mullite by the oxidation of Al-Si alloy powder was used for the manufacture of mullite via pressure molding. The mixed powder was consisted of powders of Al-Si alloy, Al2O3 and SiO2 and additives or powders of Al-Si alloy, Al2O3, SiO2 and ZrO2 and additives. Those mixed powders were milled in nonaqueous slurry in order to prevent the oxidation of Al-Si alloy. Then the green bodies were pressureless sintered in air at ≥1380 °C. The Oxidation caused an internal volume expansion, resulting in reducing shrinkage stresses during reaction- bonding of composites, which minimized the sensitivity to crack formation. Comparing with non zirconia reinforced mullite composites, the effect of the microstructure and mechanical properties of mullite composites were studied.
Wei Pan and Jianghong Gong
S. Li et al., "Microstructure and Mechanical Properties of Mullite Composites via Pressure Molding and by Oxidation of an Al-Si Alloy Powder", Key Engineering Materials, Vols. 368-372, pp. 815-817, 2008