Abstract

Ultrafine WC-10wt.%Co cemented carbides powders were synthesized by direct carburization. W-Co composite powders and carbon black powders were mixed by wet ball milling and dried. The mixed powders were heated to 800 °C with heating rate of 8.2°C/min and held for various times in flowing H_2. For carbon addition of 140%, the carburization was completed by heating at 800°C for 4 hours. The carburization time decreased with increasing amount of carbon and carburization was completed by heating at 800 °C for 2 hours with carbon addition of 150%. WC-10 wt%Co cemented carbides powders fabricated by direct carburization have nanoscale WC(/leqq100 nm) size.