S P Chaudhuri
Articles written in Bulletin of Materials Science
Volume 19 Issue 2 April 1996 pp 373-381
A glass of composition similar to that found in fireclay refractories was synthesized and subsequently nucleated with Cr2O3, V2O5 and TiO2. These glasses were heat-treated for crystallization of the mullite phase. The mullite content, the crystallization of mullite and the effect of temperature on the rate were investigated. The concentration of the nucleating oxides and the size and charge of their cations influence both the mullite content obtained and the crystallization rate.
Volume 19 Issue 2 April 1996 pp 383-392
Poor-grade fireclay products contain substantial amount of glass. A glass of similar composition was synthesized, nucleated and heat-treated for crystallization of mullite. The size and size-distribution of mullite crystals, the rate of change of size and the aspect ratio of the crystals were investigated in relation to the nucleating agents and temperature.
Volume 20 Issue 7 October 1997 pp 949-963
A poor-grade fireclay was mixed with three nucleating agents, namely Cr2O3, V2O5 and TiO2. The fireclay and oxide mixed fireclay were fired at 1300°C for 1 h, cooled down to room temperature and then heat-treated at 1150°C for 15h. These were also heat-treated at 1150°C for 15 h after cooling down to 1150°C from the peak temperature. The heat-treatment caused ceramization of the glassy phase in the fireclay samples, and the samples, mineralogical composition and microstructure were investigated. Ceramization brought about significant changes in the microstructure only.
Volume 20 Issue 7 October 1997 pp 965-974
Low-grade fireclay refractories contain large amounts of glassy phase. The properties, e.g. mechanical strength, thermal-shock resistance, refractoriness-under-load, refractoriness and also porosity and bulk density of these refractories before and after ceramization of their glassy phase were investigated. The glassy phase was ceramized by incorporating Cr2O3, V2O5 and TiO2 into the refractories as nucleating agents and subsequent heat-treatment. Significant improvement in mechanical strength and thermal-shock resistance of the ceramized refractories was observed.
Volume 22 Issue 1 February 1999 pp 37-47 Composites
Several zirconia-mullite and alumina-zirconia composites were prepared and their physical, chemical, mechanical and thermal properties determined. The phase assemblage, size of ZrO2 crystals and microstructure of the composites were ascertained. This paper embodies a comparison of the alumina-zirconia and zirconia-mullite composites with respect to their properties and also the constitution-property relationships between each group of composites. Alumina-zirconia composites (AZ) were found to be superior to zirconia-mullite composites (prepared through ZMS or ZMC route) in almost all respects. Thermal-shock resistance and hydration resistance of the clay-based zirconia-mullite (ZMC) composites and alumina-zirconia (AZ) composites were almost at par.
Volume 42 | Issue 5
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