TUNGSTEN CARBIDE (WC) SYNTHESIS FROM NOVEL PRECURSORS

Oxide powders were coated with carbon by the cracking of propylene, mixed with a substantial amount of carbon black, and finally treated at temperatures in the range of 600-1400 C in flowing Ar or 10% H2-Ar atmosphere to synthesise WC. The produced powders were characterised using TEM, BET surface area analyser, XRD and chemical analysis. The results obtained for various types of precursors treated in different atmospheres indicated that the coated precursors produced high quality powders. Single phase, submicron WC powders were synthesised at temperatures as low as 1100 C. WC powders produced at 1400 C were submicron (3-5 m2/g), single phase, and had low oxygen content (0.2-0.5 wt%). Sintering tests demonstrated that these powders could be densified to near theoretical density using 20 wt% Co binder at 1500 C for 2 h in flowing 10% H2-Ar atmosphere. 18 refs.