In the present study, anorthite (CaAl2Si2O8) porcelain was fabricated using Ca(OH)2, Al(OH)3, quartz, aluminous cement and feldspar as raw materials. Two compositions were formulated (coded as CAQ and CFQ)and their physico-mechanical properties (%AP, BD, flexural strength) were studied and compared. CAQ (21.2 wt% Ca(OH)2, 44.5 wt% Al(OH)3 and 34.3 wt% quartz) shows very poor densification and strength even after heating at 1450° C, although anorthite formation is observed on heating it at various temperatures. On the other hand, CFQ (48.6 wt% aluminous cement, 29.37 wt% feldspar and 22.06 wt% quartz) achieved full densification and superior strength at 1450° C with more anorthite formation compared to CAQ. X-ray diffraction and scanning electron microscope studies were also carried out to analyse the phase and microstructure evolution. The coefficient of thermal expansion of the anorthite-based sample was found to be lower than quartz and mullite porcelain which suggests its application as cooking ware.
Volume 42 | Issue 6
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