Sinterability of forsterite prepared via solid-state reaction

Abstract

In this work, the sinterability of forsterite powder synthesized via solid-state reaction was investigated. X-ray diffraction (XRD) analyses indicate that the synthesized powder possessed peaks that correspond to stoichiometric forsterite. Scanning electron micrographs revealed that the powders were formed agglomerates, which were made up of loosely packed fine particles. Subsequently, the forsterite powders were cold isostatically pressed into a disk shape under 200 MPa and sintered in air at temperature ranging from 1200°C to 1500°C (interval of 50°C) with ramp rate of 10°C/min and dwelling time of 2 h. The sinterability of each sintered samples was examined in terms of phase stability, relative density, Vickers hardness, fracture toughness, and microstructural examination. XRD examination on all the sintered samples exhibited pure forsterite, in which the generated peaks were found to be in a good agreement with JCPDS card no. 34-0189. The densification of forsterite progressed to reach a maximum relative density of ~91% at 1500°C. This study also revealed that high-strength forsterite ceramic can be synthesized via solid-state reaction as forsterite attained favorable mechanical properties, having fracture toughness of 4.88 MPam1/2 and hardness of 7.11 GPa at 1400°C. © 2013 The American Ceramic Society.