Structural and electronic properties of chromium carbides and Fe-substituted chromium carbides

Abstract

Abstract Chromium carbides are coated over base metal (Fe) to increase wear and corrosion resistance. The electronic structure and bonding properties for chromium carbide bulk phases (Cr 3 C 2 , Cr 7 C 3 and Cr 23 C 6 ) and Fe-substituted chromium carbides is investigated using Density Functional Theory (DFT). The bonding in these carbides has been interpreted in the form of partial density of states, electron density distribution and Mulliken population method. Cr 3 C 2 exhibits the strongest covalent character while Cr 7 C 3 displays the highest metallicity. Cr 3 C 2 showed the highest stability among the chromium carbide phases. In the Fe-substituted chromium carbides (Cr 2 FeC 2 ), the site preference of Fe in Cr 3 C 2 system has been reported. In Fe-substituted chromium carbides also show both of metallic and covalent character and Cr 2 Fe3C 2 is found to be the most stable Fe-substituted chromium carbide system.