Effect of sintering temperature on the structural and physical properties of forsterite using amorphous rice husk silica as refractory precursors

Abstract

This study aims to investigate the effect of sintering temperatures on both the phase formation and physical characteristics of forsterite prepared from rice husk silica and magnesium nitrate hydrate. The samples were subjected to sintering temperatures of 1000–1300 °C, and the development of structures was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Some physical properties include density, porosity, hardness, bending strength, and thermal expansion coefficient of the samples were measured. It is concluded that forsterite formation started at 1000 °C, and its abundance increased slowly from an increased temperature up to 1300 °C, resulting in increased phase contents from 87.7 to 90.0 wt%. Thermal expansion coefficient of the samples with increasing temperature of sintering from 1100 to 1300 °C reaches the relatively constant value of 9.1 × 10−6/°C, with the main crystalline phase being forsterite.