Effect of Whole and Partial Substitution of Rice Husk Ash for Quartz in Triaxial Porcelain Composite Fabrication

Rice husk ash (RHA) was wholly and partially substituted for quartz in a triaxial porcelain mixture of kaolin, quartz, and feldspar in this study. The effect of this substitution on the physico-mechanical properties (bulk density, apparent porosity, linear shrinkage, and flexural strength) was studied at heating temperatures of 1200oC, 1300oC and 1400oC. Investigation of the phase and microstructural evaluation was analysed using SEM/EDX and XRD, respectively. The sintered samples showed improved physico-mechanical properties as the temperature increases as expected of porcelain materials. There was no significant change in the bulk density; however, the partially substituted compositions (60 and 40% RHA) displayed better flexural strength when compared to the wholly replaced sample and unreplaced sample. The presence of mullite and cristobalite in the sintered mix contributed to this development. The study, therefore, reveals that partial and controlled replacement of quartz with RHA yield beneficial results.