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On the mechanism of fatigue crack initiation in high-angle grain boundaries
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SYSNO ASEP 0557623 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title On the mechanism of fatigue crack initiation in high-angle grain boundaries Author(s) Mazánová, Veronika (UFM-A)
Heczko, Milan (UFM-A) ORCID
Polák, Jaroslav (UFM-A) RID, ORCIDNumber of authors 3 Article number 106721 Source Title International Journal of Fatigue. - : Elsevier - ISSN 0142-1123
Roč. 158, MAY (2022)Number of pages 7 s. Language eng - English Country GB - United Kingdom Keywords stage-i propagation ; high-strain fatigue ; twin boundaries ; crystallographic orientation ; slip bands ; intrusions ; extrusions ; nucleation ; growth ; steel ; Fatigue crack initiation ; High-angle grain boundary ; Persistent slip bands ; Extrusions and intrusions ; Void-like discontinuities Subject RIV JG - Metallurgy OECD category Materials engineering R&D Projects GA18-03615S GA ČR - Czech Science Foundation (CSF) LQ1601 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) Method of publishing Limited access Institutional support UFM-A - RVO:68081723 UT WOS 000792829100008 EID SCOPUS 85122941848 DOI 10.1016/j.ijfatigue.2022.106721 Annotation Fatigue crack initiation in high-angle grain boundaries is often observed experimentally, however, its mechanism is a subject of controversy. Low cycle fatigue loading has been applied to super-austenitic stainless steel Sanicro 25 and surface features developed during cyclic loading with high strain amplitudes were studied and analyzed using SEM, EBSD and FIB cuts. Dense array of persistent slip markings developed on the surface of grains was found. Extrusions and intrusions emerged not only in the direction of the surface but also normal to the grain boundaries. Growing extrusions were bent and started to push two neighbor grains locally apart leading to production of void-like discontinuities. Deepening intrusions produced void-like defects or microcracks on the grain boundary. Both these processes led to the substantial weakening of the grain boundary. Coalescence of void-like discontinuities and microcracks on the grain boundary during cyclic loading led to the production of the grain boundary crack. Presented and discussed experimental findings lead to novel mechanism of high-angle grain boundary crack initiation and raise serious doubts about the theories of brittle-like origin of grain boundary cracks. Workplace Institute of Physics of Materials Contact Yvonna Šrámková, sramkova@ipm.cz, Tel.: 532 290 485 Year of Publishing 2023 Electronic address https://www.sciencedirect.com/science/article/pii/S0142112322000020?via%3Dihub
Number of the records: 1