Number of the records: 1  

LOW CYCLE FATIGUE BEHAVIOR AND FATIGUE CRACK INITIATION IN MAR-M247 AT 700 °C

  1. 1.
    SYSNO ASEP0491917
    Document TypeC - Proceedings Paper (int. conf.)
    R&D Document TypeConference Paper
    TitleLOW CYCLE FATIGUE BEHAVIOR AND FATIGUE CRACK INITIATION IN MAR-M247 AT 700 °C
    Author(s) Šulák, Ivo (UFM-A) ORCID
    Obrtlík, Karel (UFM-A) RID, ORCID
    Hrbáček, K. (CZ)
    Number of authors3
    Source TitleMETAL 2017 - 26th International Conference on Metallurgy and Materials, Conference Proceedings. - Ostrava : Tanger, 2017 - ISBN 978-80-87294-79-6
    Pagess. 1580-1586
    Number of pages7 s.
    Publication formMedium - C
    ActionMETAL 2017: International Conference on Metallurgy and Materials /26./
    Event date24.05.2017 - 26.05.2017
    VEvent locationBrno
    CountryCZ - Czech Republic
    Event typeWRD
    Languageeng - English
    CountryCZ - Czech Republic
    KeywordsNickel-based superalloy ; cyclic stress-strain curve ; Fatigue life ; fatigue crack initiation ; focus ion beam
    Subject RIVJL - Materials Fatigue, Friction Mechanics
    OBOR OECDAudio engineering, reliability analysis
    R&D ProjectsGA15-20991S GA ČR - Czech Science Foundation (CSF)
    TA04011525 GA TA ČR - Technology Agency of the Czech Republic (TA ČR)
    Institutional supportUFM-A - RVO:68081723
    UT WOS000434346900255
    EID SCOPUS85043373713
    AnnotationThe second generation nickel-based superalloy MAR-M247 offers a satisfying combination of fatigue and creep properties and oxidation and corrosion resistance that are required for application at elevated temperatures in hostile environments. The microstructure consists mainly of the face centred cubic γ matrix and ordered γ´ strengthening precipitates (L12 crystal structure). The present work focuses on low cycle fatigue (LCF) behaviour of polycrystalline nickel-based superalloy MAR-M247 at high temperature. LCF tests were conducted on cylindrical specimens in a symmetrical push-pull cycle under strain control with constant total strain amplitude and strain rate at 700 °C in ambient air. Cyclic stress-strain curves and fatigue life curves in the representation of plastic strain amplitude vs. stress amplitude and stress amplitude vs. the number of cycles to failure, respectively, were plotted and compared with data obtained on Inconel 713LC. Special attention was paid to the investigation of crack initiation in MAR-M247 during low cycle fatigue. Crack initiation sites were studied by means of scanning electron microscopy (SEM) in dual beam microscope TESCAN LYRA 3 XMU FESEM equipped with focus ion beam (FIB). Specimens’ surface observations revealed the formation of pronounced surface relief indicating localisation of plastic deformation. Observations in transmission electron microscope (TEM) confirmed localisation of cyclic plastic deformation in persistent slip bands along {111} slip planes. Fractographic analysis revealed fatigue crack initiation sites. Fatigue crack propagation in stage I was typical of smooth facets up to 500 μm long.
    WorkplaceInstitute of Physics of Materials
    ContactYvonna Šrámková, sramkova@ipm.cz, Tel.: 532 290 485
    Year of Publishing2020
Number of the records: 1