The bond characters and phase stability effects of Cr Mo and Ni in bulk -Fe(C

Abstract

Based on density functional theory and using the first-principle method, the electronic structures of -Fe(C) with Cr, Mo, and Ni are calculated within the generalized gradient approximation (GGA)-PW91. Meanwhile, the effects of alloys on the bonding characters and austenitic stability are studied by the overlap population, mulliken charge population, density of states, charge density difference, and cohesive energy. The results show that there coexist the metallic bond, covalent bond and weak ionic bond in each of -Fe(C)-Cr and -Fe(C)-Mo unit cell, while only metallic bond and covalent bond coexist in -Fe(C)-Ni. The bonding orbit is mainly determined by the interactions between the d orbits of alloy atoms and the orbits of Fe 3d and C 2p. Moreover, the effects of Cr, Mo, Ni solution on austenitic stability are investigated by studying the influence of alloy element on -Fe(C) electronic structure.