Please use this identifier to cite or link to this item: doi:10.22028/D291-23995
Title: Crack initiation and propagation during high-temperature fatigue of oxide dispersion-strengthened superalloys
Author(s): Elzey, D. M.
Arzt, Eduard
Language: English
Year of Publication: 1991
OPUS Source: Metallurgical transactions / A. - 22. 1991, 4, S. 837-851
SWD key words: Rissausbreitung
Mechanische Eigenschaft
DDC notations: 620 Engineering and machine engineering
Publikation type: Journal Article
Abstract: The mechanisms of crack initiation and propagation have been investigated in two oxide dispersion-strengthened (ODS) Ni-base superalloys under conditions of symmetric low-cycle fatigue (LCF) and creep-fatigue. The behavior of both ODS alloys is compared with that of conventional alloys of otherwise similar composition. While the improvement in fatigue resistance previously reported for ODS metals and alloys is confirmed by the present study for temperatures below about 0.6T m, the potential advantage of dispersion strengthening is not being exploited by the current generation of ODS superalloys at higher temperatures; crack initiation is found to occur prematurely due to the presence of recrystallization defects in the form of fine grains. The mechanism of crack initiation at fine grains is creep-type cavitation on boundaries transverse to the applied stress. Experimental results indicating the influence of temperature, loading frequency, and waveshape on the crack initiation rate are presented and discussed in detail. A qualitative correlation between waveshape and creep-fatigue life is suggested based on the macroscopic inelastic strain rate which is determined by the waveform and limits in turn the rate at which cavity growth can be accommodated.
Link to this record: urn:nbn:de:bsz:291-scidok-20119
Date of registration: 30-Jan-2009
Faculty: SE - Sonstige Einrichtungen
Department: SE - INM Leibniz-Institut für Neue Materialien
SciDok - Der Wissenschaftsserver der Universität des Saarlandes

Files for this record:
File Description SizeFormat 
ea199105.pdf8,96 MBAdobe PDFView/Open

Items in SciDok are protected by copyright, with all rights reserved, unless otherwise indicated.