Influence of crystal orientation on the thermomechanical fatigue behaviour in a single-crystal superalloy
2015 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, Vol. 623, no 19, 68-77 p.Article in journal (Refereed) Published
In this study, the influuence from crystal orientation on the thermomehanical fatigue (TMF) behaviour of the recently developed single-rystal superalloy STAL-15 is considered, both from an experimental and a nite element (FE) perspective. Experimental results show that there is a strong inuence from the elastic stiffness, with respect to the loading direction, on the TMF life. However, the results also indicate that the number of active slip planes duringdeformation inuence the TMF life, where specimens with a higher number of active slip planes are favoured compared to specimens with fewer active slip planes. The higher number of active slip planes results in a more widespread deformation compared to a more conentrated deformation when only one slip plane is active. Deformation bands with smeared and elongated γ-precipitates together with deformation twinning were found to be major deformation mechanisms, where the twins primarily were observed in specimens with several active slip planes. From an FE-perspective, therystal orientation with respect to the loading direction is quantied and adopted into a framework which makes it possible to describe the internal crystallographic arrangement and its entities in a material model. Further, a material model which incorporates the crystalorientation is able to predict the number of slip planes observed from microstructural observations, as well as the elasticstiness of the material with respect to the loading direction.
Place, publisher, year, edition, pages
Elsevier, 2015. Vol. 623, no 19, 68-77 p.
Single-crystal superalloy, Crystal orientation dependence, Thermome hanical fatigue, Deformation mechanisms, Finite element
IdentifiersURN: urn:nbn:se:liu:diva-111639DOI: 10.1016/j.msea.2014.11.026ISI: 000349063100009OAI: oai:DiVA.org:liu-111639DiVA: diva2:758419
On the day of the defence day the status of this article was Manuscript.
The work has been financially supported by Siemens Industrial Turbomachinery AB in Finspang, Sweden, and the Swedish Energy Agency, via the Research Consortium of Materials Technology for Thermal Energy Processes, Grant no. KME-702. In addition, the support from the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU #2009-00971) is also acknowledged.2014-10-272014-10-272015-03-10Bibliographically approved