High-pressure and high-temperature sintering of pure cubic silicon carbide: A study on stress–strain and densification

Abstract

Silicon carbide (SiC) is a high-performance structural ceramic material with excellent comprehensive properties unmatched by metals and other structural materials. In this paper, the raw SiC powder with an average grain size of 5 μm was sintered by an isothermal compression process at 5.0 GPa and 1500 °C, and the maximum hardness of the sintered samples is 31.3 GPa. Subsequently, scanning electron microscopy was used to observe the microscopic morphology of the recovered SiC samples treated in the temperature and extended pressure range of 0 - 1500 °C and 0 - 16.0 GPa, respectively. The defects and plastic deformation in SiC grains were further analyzed by transmission electron microscopy. Further, high pressure in situ synchrotron radiation x-ray diffraction was used to study the intergranular stress distribution and yield strength under non-hydrostatic compression. This study provides a new viewpoint for the sintering of pure phase micron sized SiC particles.