Structural, electronic, magnetic and mechanical properties of Fe2SiC

Abstract First-principles calculations have been implemented to investigate the substitutional solute of Si in cementite. The thermodynamical stability of Fe2SiC is better than other M3C compounds according to the reaction energy. The magnetic features of Fe2SiC origin from the Wyckoff sites of Si atoms, the octahedron structure unit and the Fe–C bond distances. The bonding in Fe2SiC has a mixture of covalent, metallic and ionic characteristics and the substitution of Si increases the degree of the covalent bonds. The Young's modulus and shear modulus increase whereas the degree of elastic anisotropy decreases with the Si-substitution for the mechanical stable Fe2SiC. The investigation provides a theoretical prediction for the precipitated phases and their physical properties in silicon-containing steels.