Ab initio simulation of alloying effect on stacking fault energy in fcc Fe
نویسندگان
چکیده
The effect of 3d and 4d transition metal (TM) additions on the intrinsic stacking fault energy (SFE) in fcc Fe is studied to elucidate the role of alloying in the deformation mechanisms in austenitic steels. The results of ab initio calculations reveal that only Mn reduces the SFE, stabilizing the local hcp structure, whereas all other d-additions are expected to decrease the hcp? fcc transformation temperature and restrain the e-martensite formation. We predict a parabolic dependence of SFE on the atomic number of d-element across the series, with the largest increase in SFE obtained for the early and late elements in the d-series that follow the difference in the valence electrons between the TM and Fe atoms. To understand the SFE behavior in fcc Fe alloys, the driving forces for the fcc to hcp phase transformations of transition metal X and solid solution Fe–X were considered with an ab initio approach. It is found that the solution model explains the SFE trends for all TM additions except the late TMs with fully occupied d-shells (Cu and Ag). 2014 Elsevier B.V. All rights reserved.
منابع مشابه
Stacking fault energy of face-centered cubic metals: thermodynamic and ab initio approaches.
The formation energy of the interface between face-centered cubic (fcc) and hexagonal close packed (hcp) structures is a key parameter in determining the stacking fault energy (SFE) of fcc metals and alloys using thermodynamic calculations. It is often assumed that the contribution of the planar fault energy to the SFE has the same order of magnitude as the bulk part, and thus the lack of preci...
متن کاملAb initio simulations of geometrical frustration in supercooled liquid Fe and Fe-based metallic glass
We investigate short range order in liquid and supercooled liquid Fe and Fe-based metallic glass using ab initio simulation methods. We analyze the data to quantify the degree of local icosahedral and polytetrahedral order and to understand the role of alloying in controlling the degree of geometric frustration. Comparing elemental Fe to Cu P. Ganesh and M. Widom, Phys. Rev. B 74, 134205 2006 w...
متن کاملEffects of Alloying Elements on Elastic, Stacking Fault, and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys
To understand the effects of alloying elements on the creep rate of Ni-base superalloys, factors entering into a secondary creep rate are calculated via first-principles calculations based on density functional theory for 26 Ni31X systems where X = Al, Co, Cr, Cu, Fe, Hf, Ir, Mn, Mo, Nb, Os, Pd, Pt, Re, Rh, Ru, Sc, Si, Ta, Tc, Ti, V, W, Y, Zr, and Zn. They are volume, elastic properties, stacki...
متن کاملAb initio study on the variation of stacking interactions of aniline and hydrated aniline systems
The use of appropriate level of theories for studying weak interactions such as 8-8 stackinginteractions of aromatic molecules has been an important aspect, since the high level methods havelimitations for application to large molecules. The differences in the stacking energies of variousaromatic molecular structures are found significant. It is also very important for identifying the mostfavor...
متن کاملObservation of Stacking Fault Tetrahedral in TWIP Steel
Low stacking fault energy face centered cubic (FCC) materials contain characteristic defect structures. Stacking fault tetrahedral are one of those rare structures that occur under special experimental conditions. For the first time, stacking fault tetrahedral were observed in Fe-30Mn-3Al-3Si twinning induced plasticity (TWIP) steel. Their presence resulted from a quenching heat treatment.
متن کامل