Stage I fatigue cracking in MAR-M 247 superalloy at elevated temperatures

0465127 - ÚFM 2017 RIV NL eng C - Conference Paper (international conference)
Šmíd, Miroslav - Hutař, Pavel - Horník, V. - Hrbáček, K. - Kunz, Ludvík
Stage I fatigue cracking in MAR-M 247 superalloy at elevated temperatures.
21st European Conference on Fracture. Amsterdam: Elsevier, 2016, 3018–3025, s. 3018-3025. Procedia Structural Integrity, 2. ISSN 2452-3216.
[ECF21 - European Conference on Fracture /21./. Catania (IT), 20.06.2016-24.06.2016]
R&D Projects: GA TA ČR(CZ) TA04011525; GA MŠMT(CZ) ED1.1.00/02.0068
Institutional support: RVO:68081723
Keywords : Superalloy * High cycle fatigue * Elevated temperature * MAR-M 247 * Fatigue crack initiation
OECD category: Audio engineering, reliability analysis
http://www.sciencedirect.com/science/article/pii/S2452321616303961

Nickel base superalloys exhibit fatigue fracture behavior with features of brittle-like cleavage cracking under high cycle fatigue loading at temperatures up to approximately 800 °C. This specific fracture behavior was already documented in several studies, but a possible mechanism of fatigue crack propagation under this mode has not been made completely clear yet. The aim of this paper is to put more light on the phenomenon by using advanced electron microscopy techniques like electron back-scattered diffraction (EBSD) and focused ion beam (FIB) sectioning. Fractured specimens after high cycle fatigue tests were thoroughly examined with the aim to localize the fatigue crack initiation sites and accompanying features of the fatigue crack propagation. Several specimens were cross-sectioned in order to characterize active slip systems, cyclic plastic deformation localization and fatigue crack propagation. Dislocation structures were studied by transmission electron microscopy (TEM).
Permanent Link: http://hdl.handle.net/11104/0264193