Four formulations of triaxial porcelain composed from 34 – 49% clay, 13 – 22% potash feldspar, 10 – 30% Soda feldspar and 14 – 28% silica sand, were prepared from raw materials sourced from Malaysian deposits. Specimens were made using the dry pressing method and characterized in terms of constituent oxide composition, compressive strength and powder-XRD analyses, respectively. XRD studies revealed that the crystalline phases are mullite and quartz and their intensity is almost identical for all samples fired at 1250°C but there is a decrease in quartz content as temperature is increased. Samples with 28% sand content resulted in higher compressive strength compared to those containing 14% and 25% sand. The major factor influencing compressive strength was found to be porosity in samples as opposed to crystallinity. A body EP3 with 64.9% SiO2, 25.4% Al2O3, 3.6% K2O, 1.5% Na2O and 1.09% others exhibited best mechanical properties due to greater density and lower porosity formation.

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The effect of Al2O3 to the properties of whiteware porcelain such as water absorption, bulk density, flexural strength and crystalline phases were studied systematically. The result shows that the addition of alumina at maximum 5 wt.% in porcelain bodies increased the flexural strength of the fired bodies which can reach 55.5 MPa, 30% higher than 0.0% alumina content. However, slight decrease in the other physical and mechanical properties was observed with Al2O3 addition higher than 5 wt.%, which is believed to be due to increased corundum phase compared to mullite phase in porcelain body.