Nanocrystalline tungsten carbide encapsulated in carbon shells

• Published in: Nanostructured materials 1998-02, Vol.10 (2), p.179-184
• Main Authors: Li, Z.Q., Zhang, H.F., Zhang, X.B., Wang, Y.Q., Wu, X.J.
• Format: Article
• Language: English
• Subjects: Clusters, nanoparticles, and nanocrystalline materials; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Structure of solids and liquids; crystallography
• ISSN: 0965-9773; 1872-9150
• DOI: 10.1016/S0965-9773(98)00054-3

Nanocrystalline tungsten carbide with an average grain size of 12 nm was synthesized using the ion arc method. The characterization was carried out by means of XRD, TEM, and TGA. The experimental results indicate that the as-synthesized powders are mainly cubic WC 1 − x. Besides, a small amount of α-W 2C is also observed. These tungsten carbide powders are encapsulated within crystalline graphite. Owing to the ultrafine sizes of the powers, oxidation of the graphite occurs at about 350 °C. The nanocrystalline tungsten carbide transforms into WO 3 at about 670 °C.