Physics‐Based Modeling of Thermo‐Mechanical Fatigue in PWA 1484

Amaro, Robert L.; Antolovich, Stephen D.; Neu, Richard W.; Staroselsky, Alexander

doi:10.1002/9781118516430.ch53

Cited by 8 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These components are often cast from nickel-base superalloys in the form of singlecrystals. The material anisotropy of single-crystal materials adds an extra dimension of complexity to the modelling, testing and understanding of the fracture mechanisms [3][4][5][6][7][8][9][10][11]. The service life of many hot components is not fully restricted by the number of cycles to crack initiation, which means that a certain amount of crack propagation is allowed before the component has to be replaced in service.…”

Section: Zusammenfassungmentioning

confidence: 99%

Aspects of Crack Growth in Single-Crystal Nickel-Base Superalloys

Busse¹

2017

View full text Add to dashboard Cite

Linköping, December 2017Cover: Front: Anisotropic stress response of an FE-simulation of an uncracked DCT specimen. Back: Stress response at the crack tip of an FE-simulation of a cracked DCT specimen.Printed by: LiU-Tryck, Linköping, Sweden, 2017 ISBN: 978-91-7685-395-5 ISSN: 0280-7971 Distributed by: Linköping University Division of Solid Mechanics SE-581 83 Linköping, Sweden © 2017 Christian Busse This document was prepared with L A T E X, November 14, 2017 No part of this publication may be reproduced, stored in a retrieval system, or be transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior permission of the author. PrefaceThe work presented in this Licentiate of Engineering thesis has been generated at the Division of Solid Mechanics at Linköping Universtiy and is part of the research project KME-702. The research has been funded by the Swedish Energy Agency and Siemens Industrial Turbomachinery AB through the Research Consortium of Materials Technology for Thermal Energy Processes, the support of which is greatly acknowledged. The research project concerns the fields of mechanical testing, microstructure investigations and modelling. This variety gave me the opportunity to learn something new in many different fields almost every day.This Furthermore, I would like to thank my friend and fellow PhD student J-L, who helped me with many fruitful discussions and makes the PhD life more joyful.Finally, I would like to thank Nathalie, who, even though we had to part ways, has always supported me and was always there for me. In a way, I am where I am today because of you. I will always be grateful for that and I will never forget you. Thank you! AbstractThis Licentiate of Engineering thesis is a product of the results generated in the research project KME-702, which comprises modelling, microstructure investigations and material testing of cast nickel-base superalloys.The main objective of this work is to model the fatigue crack propagation behaviour in single-crystal nickel-base superalloys. To achieve this, the influence of the crystal orientations on the cracking behaviour is assessed. The results show that the crystal orientation is strongly affecting the material response and must be accounted for. Furthermore, a linear elastic crack driving force parameter suitable for describing crystallographic cracking has been developed. This parameter is based on resolved anisotropic stress intensity factors and is able to predict the correct crystallographic cracking plane after a transition from a Mode I crack. Finally, a method to account for inelastic deformations in a linear elastic fracture mechanics context was investigated. A residual stress field is extracted from an uncracked finite-element model with a perfectly plastic material model and superimposed on the stress field from the cracked model with a linear elastic material model to account for the inelastic deformations during the determination of the crack driving force. The modellin...

show abstract

Section: Zusammenfassungmentioning

confidence: 99%

Aspects of Crack Growth in Single-Crystal Nickel-Base Superalloys

Busse¹

2017

View full text Add to dashboard Cite

show abstract

“…The loads 4 are not in phase with the strains and this situation is referred to as TMF, as explained earlier. In recent years, research aimed ultimately at developing a life prediction methodology has been carried out in our laboratories and the evolution of this work has been reported in numerous publications [72][73][74][75][76][77][78][79][80]. The most important findings are reprised in this section but it is appropriate to note that the work was motivated, in part, by simple experiments designed to simulate TMF in René 80 [78,80].…”

Section: Environment-fatigue Interactions In Thermo-mechanical Fatiguementioning

confidence: 99%

Microstructural aspects of fatigue in Ni-base superalloys

Antolovich

2015

Phil. Trans. R. Soc. A.

Self Cite

View full text Add to dashboard Cite

Nickel-base superalloys are primarily used as components in jet engines and land-based turbines. While compositionally complex, they are microstructurally simple, consisting of small (50–1000 nm diameter), ordered, coherent Ni 3 (Al,Ti)-type L1 2 or Ni 3 Nb-type DO 22 precipitates (called γ ′ and γ ′′ , respectively) embedded in an FCC substitutional solid solution consisting primarily of Ni and other elements which confer desired properties depending upon the application. The grain size may vary from as small as 2 μm for powder metallurgy alloys used in discs to single crystals the actual size of the component for turbine blades. The fatigue behaviour depends upon the microstructure, deformation mode, environment and cycle time. In many cases, it can be controlled or modified through small changes in composition which may dramatically change the mechanism of damage accumulation and the fatigue life. In this paper, the fundamental microstructural, compositional, environmental and deformation mode factors which affect fatigue behaviour are critically reviewed. Connections are made across a range of studies to provide more insight. Modern approaches are pointed out in which the wealth of available microstructural, deformation and damage information is used for computerized life prediction. The paper ends with a discussion of the very important and highly practical subject of thermo-mechanical fatigue (TMF). It is shown that physics-based modelling leads to significantly improved life prediction. Suggestions are made for moving forward on the critical subject of TMF life prediction in notched components.

show abstract

“…The inherent crystallographic structure of single-crystal nickel-base superalloys results in a complex material behaviour, which leads to many challenges in testing, modelling and prediction of the crack initiation and growth be-haviour [2][3][4][5][6][7][8]. It has frequently been observed that two distinct cracking modes are present in these materials; crystallographic cracking on the octahedral {111}planes and Mode I cracking perpendicular to the loading direction [9][10][11][12][13][14], cf.…”

Section: Introductionmentioning

confidence: 99%