The effect of additives on the properties and microstructures of Al2O3-C refractories

The effect of Al and Si additions on the properties and microstructure of Al2O3-C refractories has been studied. The results showed an increase in the strength and a decrease in porosity values with the increase in the Al content in the samples. The increase in firing temperature at a constant level of Al content had a deteriorating effect on the above mentioned properties. The oxidation resistance in the Al containing samples showed an improvement in the range of Al content studied in this work. Improvement in the oxidation resistance was also seen in the samples containing Si as additive. However, unlike the Al-case higher firing temperatures in the Si containing samples led to an increase in the strength and a decrease in the porosity values. The available thermodynamic data as well as x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used in the interpretation of the experimental data. (c) 2006 Springer Science + Business Media, Inc.