Superior low-cycle fatigue properties of CoCrNi compared to CoCrFeMnNi

SCRIPTA MATERIALIA

卷:194

Article

Lu, Kaiju¹  Chauhan, Ankur¹  Walter, Mario¹  Tirunilai, Aditya Srinivasan²  Schneider, Mike³  Laplanche, Guillaume³  Freudenberger, Jens^4,5  Kauffmann, Alexander²  Heilmaier, Martin²  Aktaa, Jarir¹ 

[1] Karlsruhe Inst Technol KIT, Inst Appl Mat, Hermann Von Helmholtz Pl 1, D-76344 Eggenstein Leopoldshafen, Germany

[2] Karlsruhe Inst Technol KIT, Inst Appl Mat, Engelbert Arnold Str 4, D-76131 Karlsruhe, Germany

[3] Ruhr Univ Bochum, Inst Werkstoffe, D-44801 Bochum, Germany

[4] Leibniz Inst Solid State & Mat Res Dresden IFW Dr, Helmholtzstr 20, D-01069 Dresden, Germany

[5] Tech Univ Bergakad Freiberg, Inst Mat Sci, Gustav Zeuner Str 5, D-09599 Freiberg, Germany

关键词: High- and medium-entropy alloys;    Fatigue;    Transmission electron microscopy (TEM);    Dislocation structure;   

DOI  :  10.1016/j.scriptamat.2020.113667

来源: Elsevier

【 摘 要 】

We report on the low-cycle fatigue behavior of single-phase, face-centered cubic CoCrNi and CoCrFeMnNi at room temperature. Both alloys manifest cyclic hardening followed by softening and a near steady state until failure. CoCrNi exhibits higher strength, lower inelastic-strain, and longer lifetime than CoCrFeMnNi. For both alloys, microstructural investigations reveal no noticeable changes of texture, grain size and twin fraction. Nevertheless, CoCrNi exhibits planar dislocation structures, while CoCrFeMnNi shows well-defined wavy dislocation structures. This is due to CoCrNi lower stacking fault energy, which enhances planar slip and delays deformation localization leading to its superior fatigue resistance, compared to CoCrFeMnNi. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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