Ab-initio study of C and N point defects in the C14-Fe2Nb phase

被引：5

作者：

Ladines, A. N. ^{[1
,2
]}

Drautz, R. ^{[1
]}

Hammerschmidt, T. ^{[1
]}

机构：

[1] Ruhr Univ Bochum, ICAMS, D-44801 Bochum, Germany

[2] De La Salle Univ, Dept Phys, Manila, Philippines

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2017年 / 693卷

关键词：

TOTAL-ENERGY CALCULATIONS; CLOSE-PACKED PHASES; WAVE BASIS-SET; LAVES PHASE; STEELS; METALS; HYDROGEN; NITROGEN;

D O I：

10.1016/j.jallcom.2016.10.030

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Nb-alloying of steels can lead to the formation of topologically close-packed (TCP) phases, particularly Fe2Nb Laves and Fe7Nb6 mu phases. The stability of these TCP phases is strongly affected by the presence of light elements like C and N. We calculate the solution energy of C and N in C14-Fe2Nb using density functional theory. N shows a strong preference to dissolve in larger interstitial voids while C shows a strong tendency to bind with a neighbouring Nb atom. The computed solution energies suggest N incorporation into Fe2Nb Laves phases while C is hardly soluble. The N-N interaction in Fe2Nb is strongly attractive and twice as strong as that of C-C. A comparison to C interstitials in the mu-Fe7Nb6 phase shows similar dependence of the solution energy on the atomic environment. In order to aid future work, we additionally provide the coordinates of interstitial sites in all TCP phases (A15, Zr4Al3, C14, C15, C36, chi, mu, sigma, M, P, delta and R.) in the supplementary material. (C) 2016 Elsevier B.V. All rights reserved.

引用

页码：1315 / 1322

页数：8