2018-Sustainable Industrial Processing Summit
SIPS2018
Volume 6. New and Advanced Materials and Technologies
| Editors: | F. Kongoli, F. Marquis, P. Chen, T. Prikhna, N. Chikhradze |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2018 |
| Pages: | 392 pages |
| ISBN: | 978-1-987820-92-8 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Material Life Prediction for Sustainable Development
Xijia Wu1;1NATIONAL RESEARCH COUNCIL CANADA, Ottawa, Canada;
Type of Paper: Keynote
Id Paper: 199
Topic: 43
Abstract:
Sustainable development demands advanced materials to transform or conserve energy, which have to satisfy the durability requirements under working conditions with enhanced energy performance. Constitutive modeling and life prediction are core tasks for durability design, especially with thin margins at increasing operating temperature and lowering weight. Traditionally, these two tasks were handled separately, via phenomenological approaches that employ too many empirical correlations, with parameters that do not physically connect to each other. This is not the way to go, when facing the challenges of sustainable development.
Recently, an integrated creep-fatigue theory (ICFT) has been developed, which constructs the material constitutive law based on physical decomposition of the total deformation as the sum of elastic strain, rate-independent plastic strain, intragranular dislocation glide, climb, as well as grain boundary sliding [1]. This mechanism-based approach allows delineation of inelastic deformation in creep, fatigue, and thermo-mechanical fatigue into mechanism strains, which in turn describes the various forms of physical damage, such as persistent slip bands, grain boundary cavitation and cracking in relation to the responsible mechanism(s), respectively. Furthermore, the holistic damage accumulation in a material under random thermomechanical loading generally consists of nucleation of surface/subsurface cracks by fatigue [2], environmental effects, and their propagation in coalescence with internally distributed damage such as cavities promoted by creep.
Application of ICFT to creep has led to a deformation mechanism-based true-stress (DMTS) model that describes the three-stage creep behaviour with the influence of oxidation [3]. The DMTS model can be used for long-term creep life prediction. Application of ICFT to low-cycle fatigue and thermomechanical fatigue of ductile cast iron and austenitic cast steels has demonstrated that the complicated hysteresis behaviors are governed by fundamental deformation mechanisms operating under the corresponding loading profiles [4,5,6]. In general, ICFT provides an integrated approach to constitutive modeling and life prediction with the physics-based "genome" to include all effects of environment and material internal damage, enabling a holistic durability analysis for materials under user-specified loading profiles.
Keywords:
New and advanced technology;References:
[1] X.J. Wu, Key Engineering Materials 627 (2015) 341-344.[2] X.J. Wu, Fat. Fract. Eng. Mat. & Struct. (2017) DOI: 10.1111/ffe.12736.
[3] X.Z. Zhang, X.J. Wu, R. Liu, J. Liu, M.X. Yao, Materials Science & Engineering A 689 (2017) 345-352.
[4] X.J. Wu, G. Quan, R. MacNeil, Z. Zhang, C. Sloss, Metall. and Mater. Trans. 45A (2014), 5088-5097.
[5] X.J. Wu, G. Quan, R. MacNeil, Z. Zhang, X. Liu, C. Sloss, Metall. and Mater. Trans. 46A (2015) 2530-2543.
[6] X. J. Wu, G. Quan, and C. Sloss. Metall. and Mater. Trans A. 48A (2017) 4058-4071.