Silica Sol as a Filler in Process of Materializing Mullite Fiber (SiO₂.Al₂O₃)

Abstract Research has been carried out on the effect of adding silica sol as a filler in making mullite fiber (SiO2.Al2O3). The process of making mullite fiber is carried out using the cast molding method. Sample preparation of (I)silica sol and alumina fiber. (II) silica sol with alumina fiber and kaolin. (III) alumina fiber with kaolin and distilled water. Then the samples were mixed until homogeneous in their respective containers. Then printed in a PVC pipe measuring 2.81 cm in diameter and 1.5 cm high. Mullite fiber samples were dried at a temperature of 110°C for 1 hour, then sintered at a temperature of 1200°C, 1300°C, 1400°C, 1500°C. The density of mullite fiber increases linearly, the porosity decreases linearly, and the compressive strength of mullite fiber increases linearly as the sintering temperature increases. XRD characterization shows that in the three mullite fiber samples the same phase appears, namely mullite, sillimanite has an orthorhombic structure, and cristobalite has a tetragonal structure.