Production and characterization of ultrafine WC powders

Abstract The conventional calcination–reduction–carburization (CRC) process offers the potential to manufacture commercial WC powders with median SEM grain sizes below 0.5 μm (ultrafine grades). Strict process control and a high degree of automation have led to increased powder uniformity and high lot-to-lot reliability. The high potential and flexibility of the CRC process is shown by the development of tailor-made WC powders with regard to subsequent alloy manufacturing. R&D powders have successfully been processed in full-scale units exhibiting SEM grain sizes of 0.15– 0.20 μm . This paper discusses the powder characteristics of various ultrafine WC powder grades, stemming from the conventional CRC process. Analytical characterization include also field-emission SEM, bright-field TEM, EDX analysis and XRD-line broadening.