Abstract
Ultrafine SiC powders with average size of about 0.1μm were produced by arc discharge between silicon (positive) and carbon (negative) electrodes in about 50KPa argon containing 0.7KPa methane. The obtained powders were purified by removng silicon and carbon, and then compacted into cylinders 3mm in diameter and 3mm high. The cylinders were pressed at a pressure 6GPa at 1600°C for 10min. They sintered to almost full density with the grain size less than 1μm. Vickers hardness was 36.3GPa for one of the sintered samples and KIC-value was 4.91MNm-2/3, for other one.
