Mechanical properties of vanadium carbide and a ternary vanadium tungsten carbide

✍ Scribed by Zhimei Sun; R. Ahuja; J.E. Lowther

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 235 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.01.043

✦ Synopsis

Ab initio total energy calculations are performed on non-stoichiometric vanadium carbide with supercells representing vacancy concentrations of VC 0.875 and VC 0.75 . The VC 0.875 supercell retains a cubic symmetry whilst in the case of the VC 0.75 supercell C vacancies located in close proximity have the lowest energy configuration and the cubic lattice slightly distorts to a monoclinic symmetry. Using a stress-strain calculational procedure, the elastic constants of both the cubic and the monoclinic systems are deduced. In all cases C vacancies decrease the elastic moduli.

A similar analysis is then applied to consider when W is incorporated into VC. In this case it is found that the elastic moduli increase with W content suggesting that a V-W-C alloy could have significant potential as a novel hard material.