Optimizing the Synthesis of Nanostructured Tungsten Carbide Powders by Effective Combination of Carbon Sources and Atmospheres
Paper i proceeding, 2014
Nanostructured WC powders provide remarkable and technologically attractive properties due to the fine microstructures obtained after sintering. Synthesis of ultrafine WC powders from tungsten oxides can be achieved through a thermal activation of WO3+C mixes that promotes reduction and subsequent carburization. The maximum temperature of this process must be kept as low as possible in order to avoid excessive grain growth and agglomeration of particles. In this work, tungsten carbide powders have been synthesized from WO3 precursors combined with carbon sources with different characteristics (degree of crystallinity, specific surface area, etc.) under inert and reducing atmospheres (Ar and Ar-50%H2). Mixability of the different carbon sources with WO3 plays an important role in the subsequent thermal activation process. The effectiveness of the synthesis is discussed based on the effect of the type of carbon source used and the processing atmosphere.