On the mechanism of fatigue and dwell-fatigue crack initiation in Ti-6Al-4V

SCRIPTA MATERIALIA

卷:183

Article

Lavogiez, Cyril¹  Hemery, Samuel¹  Villechaise, Patrick¹ 

[1] Univ Poitiers, Inst Pprime, Phys & Mech Mat Dept, UPR CNRS 3346,CNRS ENSMA,ENSMA, Teleport 2,1 Ave Clement Ader,BP 40109, F-86961 Futuroscope, France

关键词: Titanium alloys;    Fatigue;    Slip;    Grain boundary;    Dwell-fatigue;   

DOI  :  10.1016/j.scriptamat.2020.03.031

来源: Elsevier

【 摘 要 】

In the present study, the mechanism of fatigue and dwell-fatigue crack initiation was investigated in Ti-6Al-4V with a bi-modal microstructure. While substantial dwell-fatigue life debit was evidenced, microstructural configurations associated with crack nucleation are similar and suggest a unique mechanism for fatigue and dwell-fatigue loadings. Pairs of a grains well oriented for basal slip and separated by a (0001) twist grain boundary were found to be critical configurations for crack initiation. Intense slip is localized at the boundary and precedes crack formation along this boundary. Data from a prior fatigue study was revisited and supports the occurrence of this mechanism. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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