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Combustion synthesis of ultrafine tungsten carbide powder

  • H.I. Won (a1), H.H. Nersisyan (a1) and C.W. Won (a1)

Abstract

The synthesis of ultrafine tungsten carbide (WC) powder has been investigated from a WO3 + Mg + C mixture via combustion technique. The values of combustion parameters were estimated over the Mg concentration range 3 to 16 mol. Fast increasing tendency of the WC/W2C phase ratio from Mg concentration has been found in the final products. Phase pure WC was prepared with more than 10 mol Mg, and a small amount of ammonium carbonate (or urea) was blended with the WO3+ C mixture. The effects of the combustion conditions on product morphology and composition were evaluated using scanning electron microscopy and x-ray diffraction analysis. The results of the investigation indicate that carbon-containing compounds significantly enhance the combustion synthesis process; leading to higher conversion efficiencies and phase pure WC formation at 1500–1550 °C. The crystalline particles of WC showed a narrow distribution in particle size, with a mean diameter around 200 nm. The results are discussed in the context of gas-phase and solid-phase transport models.

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a)Address all correspondence to this author. e-mail: rotc4379@hanmail.net

References

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