Low-Cycle Fatigue Behaviour of a Ni-Based Single-Crystal Superalloy
2014 (English)In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 891-892, 416-421 p.Article in journal (Refereed) Published
In this study, low-cycle fatigue (LCF) tests at 500 degrees C in the < 001 >, < 011 > and < 111 > directions have been performed for the Ni-based single-crystal superalloy MD2. All tests were carried out in strain control with R-is an element of = -1. The < 001 > direction has the lowest stiffness of the three directions and also shows the best fatigue properties in this study followed by the < 011 > and < 111 > directions, respectively. It is well recognised that Ni-based single-crystal superalloys show a tension/compression asymmetry in yield strength and this study shows that a tension/compression asymmetry is also present during LCF conditions. At mid-life, the < 001 > direction generally has a higher stress in tension than in compression, while the opposite is true for the < 011 > direction. For the < 111 > direction the asymmetry is found to be strain range dependent. The < 011 > and < 111 > directions show a cyclic hardening behaviour when comparing cyclic stress-strain curves with monotonic stress-strain curves. In addition, the < 011 > and < 111 > directions show a serrated yielding behaviour for a number of cycles while the yielding of the < 001 > direction is more stable.
Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2014. Vol. 891-892, 416-421 p.
Ni-based single-crystal superalloy, LCF, tension/compression asymmetry, serrated yielding
Engineering and Technology Materials Engineering
IdentifiersURN: urn:nbn:se:liu:diva-104750DOI: 10.4028/www.scientific.net/AMR.891-892.416ISI: 000337767700064OAI: oai:DiVA.org:liu-104750DiVA: diva2:698770
Fatigue 2014, 11th International Fatigue Congress, Melbourne Cricket Ground, Melbourne, Australia, 2-7 March 2014.