Stability of Zener order in martensite: an atomistic evidence

SCRIPTA MATERIALIA

卷:194

Article

Maugis, Philippe¹  Connetable, Damien²  Eymeoud, Paul¹ 

[1] Aix Marseille Univ, CNRS, IM2NP, Marseille, France

[2] CNRS INP UPS, CIRIMAT, UMR 5085, ENSIACET, 4 Allee Emile Monso,BP 44362, F-31030 Toulouse 4, France

关键词: Steels;    Long-range ordering;    Elastic behaviour;    Density functional theory (DFT);    Mean-field modelling;   

DOI  :  10.1016/j.scriptamat.2020.113632

来源: Elsevier

【 摘 要 】

Martensite is a supersaturated solid solution of carbon in body-centered iron wherein interstitial carbon atoms preferentially occupy a single octahedral sublattice. Despite a century of research, the mechanism of this long-range ordering is still a subject of debate. Recently, Zener's theory of ordering was challenged both experimentally and theoretically. In an attempt to settle the controversy, we investigated by density functional theory the ground states of Fe-C configurations having various degrees of order. We conclude that the fully Zener-ordered configurations are always the most stable energetically, thus confirming Zener's theory. Comparison with mean-field elasticity and Ising-type modelling supports the elastic origin of Zener ordering. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free