The Synthesis and Characterization of Ni-W-C Alloy Powders by H-2-CH4 Reaction with Oxides
2008 (English)In: High Temperature Materials and Processes, ISSN 0334-6455, Vol. 27, no 4, 209-222 p.Article in journal (Refereed) Published
With a view to developing a more energy-efficient and environment-friendly process route for the production of W-C based cutting tools, a single step process for the synthesis of tungsten carbides containing Ni from oxide precursors was investigated in the present work. A fluidized bed reactor was employed, wherein the mixed oxides were subjected to simultaneous reduction and carburization using H-2-CH4-Ar gas mixtures in the temperature range 1073-1273 K. The carbon potential in the gas phase could be accurately controlled by suitably adjusting the H-2/CH4 ratio. The impact of gas flow rates and temperature on the reaction product was examined. The carbide product obtained was characterized by SEM and X-ray diffraction. The results showed that the product consisted of Ni-W-C alloys, which were in consistency with the phase diagram at the temperature of reaction. The particle size of the carbides is in the range of 10(-8)m, which was dependent on the process temperature, higher temperature yielding larger grains. The results indicate that the gas-solid reaction route combining reduction and carburization is an efficient method that can be commercially applied for the production of a variety of cemented carbides.
Place, publisher, year, edition, pages
2008. Vol. 27, no 4, 209-222 p.
alloy, powder metallurgy, carburization, tungsten carbide, carbon-monoxide, surface-area, reduction, tungsten, carburization, molybdenum, catalysts, hydrogen, mixtures
IdentifiersURN: urn:nbn:se:kth:diva-18489ISI: 000266715000001OAI: oai:DiVA.org:kth-18489DiVA: diva2:336536
QC 201005252010-08-052010-08-05Bibliographically approved