Evaluation of Thermomechanical Fatigue Crack Initiation in a Single-Crystal Superalloy
2015 (English)In: PROCEEDINGS OF THE ASME TURBO EXPO: TURBINE TECHNICAL CONFERENCE AND EXPOSITION, 2015, VOL 7A, ASME Press, 2015, Vol. 7AConference paper (Refereed)
In this study the thermomechanical fatigue (TMF) crack initiation of the single-crystal nickel-base superalloy MD2 is investigated and evaluated. A series of experiments are performed of smooth specimens loaded in the nominal  and  crystal orientations, subjected to both in-phase and out-of-phase TMF loading conditions. Considering the inherent internal structure of crystallographic slip planes in single-crystals, a number of critical-plane approaches are evaluated to enable a good description of the TMF crack initiation. These are evaluated using finite element simulations and a post-process, in which crystallographic entities are extracted and compared to the experimental TMF life. A good correlation is achieved for two of the critical-plane approaches. These are able to predict the TMF crack initiation taking into account the elastic and plastic anisotropy, the tension/compression asymmetry and the creep relaxation present in the material.
Place, publisher, year, edition, pages
ASME Press, 2015. Vol. 7A
Other Materials Engineering
IdentifiersURN: urn:nbn:se:liu:diva-125127DOI: 10.1115/GT2015-42681ISI: 000375810700012ISBN: 978-0-7918-5676-5OAI: oai:DiVA.org:liu-125127DiVA: diva2:903056
ASME Turbo Expo: Turbine Technical Conference and Exposition