Synthesis of Nanostructured Tungsten Carbide (WC) from Ammonia Paratungstate-APT and its Characterization by XRD and Rietveld Refinement


Article Preview

The carbides of refractory metals like tungsten carbide (WC), tantalum carbide (TaC) and niobium carbide (NbC), has been extensively studied due to their applications in several areas of industry, because of their specific properties; such as high melting point, high hardness, wear resistance, oxidation resistance and good electrical conductivity. The tungsten carbide, particularly, is generally used at hardmetal industries due to its high hardness and wear resistance. New synthesis techniques have been developed to reduce the synthesis temperature of refractory metal carbides using more reactive precursors and gas-solid reactions for carbon reduction. The result is producing pure carbides suitable properties for production of high quality cemented carbides and more selective catalysts. In this work, pure and nanostructured WC was obtained from the ammonium paratungstate hydrate (APT), at low temperature and short reaction time. Hydrogen (H2) and methane (CH4) were used as a reducing gas and carbon source, respectively. The precursor and obtained product were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results obtained by diffraction of X-rays showed that complete reduction and carburization of APT have been took place resulted in pure WC formation. The average crystallite size was in nanometer order reaching values of approximately 20.8 nm and a surface area (BET) of 26.9 m2/g.



Edited by:

Aloisio Nelmo Klein, Uílame Umbelino Gomes, Nério Vicente Jr. and Dr. Henning Zoz




M. J. S. Lima et al., "Synthesis of Nanostructured Tungsten Carbide (WC) from Ammonia Paratungstate-APT and its Characterization by XRD and Rietveld Refinement", Materials Science Forum, Vol. 899, pp. 31-35, 2017

Online since:

July 2017




[1] B.R. Vasconcelos, A.M.V.; Morais, F.W.B. Lopes, C.P. Souza Estudo da variação da concentração de Cu na/no CuNb2O6 sintetizado a partir de reação sólidosólido. In: XVIII Congresso Brasileiro de Engenharia Química COBEQ. Paraná. 2010. Anais.. Paraná. COBEQ, 2010. 1 CD.


[2] S.T. Oyama: Introduction to the chemistry of transition metal carbides and nitrides,. In: Oyama, S. T. (ed), The Chemistry of Transition Metal Carbides and Nitrides, 1 ed, Chapter 1, Glasgow, UK, Blackie Academic & Professiona1996.


[3] F.F. P Medeiros, S. A Oliveria, C.P. Souza, A.G.P. Silva, U.U. Gomes, J.F. Souza: Mater. Sci. Eng. A Vol. 315 (2001), p.58.

[4] F.F.P. Medeiros Síntese de carbetos de tungstênio e nióbio a baixa temperatura, através de reação gás-sólido em reator de leito fixo. Doutorado (Tese). Natal, 2002. Universidade Federal do Rio Grande do Norte. (UFRN/EQ). (RN).


[5] J.M. Ledoux et al. Platimun and rhodium substitution by molybdenum and tugsten carbides for catalysis. Syntesis, activations and uses. Paris: Académie dês Sciences, 310, 707-713, (1990).

[6] A.S. Silva, H. Scatena Jr, A.E. Martinelli, C. Alves Jr.: Journal Materials Science Forum Vols. 416-418 (2003), p.60.

[7] J.F. Silva Jr, U.U. Gomes, E.O. Almeida, A.S. Silva, G.P. Pinto, C.P. Souza: Materials Science Forum Vols. 730-732 (2013), p.385.

[8] T.F. Oliveira; Análise das incertezas da quantificação de fase pelo método de Rietveld em análise de pó por difração de raios-X. Doutorado (Tese). Rio de Janeiro, 2005. Pontifícia Universidade Católica do Rio de Janeiro Sul (PUC). (RJ).


[9] A.S. Edelstein, R.C. Cammarata: Nanomaterials: Synthesis, Properties and Aplications. (Physics Publishing London, 1996).

[10] M. Boudart et al.: Journal of Catalysis Vol. 103 (1987), p.30.