Galindo-Nava, EI;
Schlütter, R;
Messé, OMDM;
Argyrakis, C;
Rae, CMF;
(2023)
A model for dislocation creep in polycrystalline Ni-base superalloys at intermediate temperatures.
International Journal of Plasticity
, Article 103729. 10.1016/j.ijplas.2023.103729.
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Abstract
A model for creep at intermediate temperatures in polycrystalline Ni-based superalloys is presented. The model is based on describing stacking fault nucleation, propagation and subsequent shear within the matrix and precipitates. The critical energy for stacking fault nucleation is obtained by minimising the energy to form a stacking fault from dislocation partials, which is promoted by local stress concentrations. The extent of stacking fault shear at a precipitate is estimated using a force balance at the interface to determine the critical shear distance The model results are validated against creep experimental data in several polycrystalline superalloys showing good agreement. Individual contributions to creep from key microstructural features, including grain size and distribution, are studied to identify which ones are more significant. Similarly, it is shown that one of the main factors controlling the creep rate is the stacking fault energy in the as it dictates the stacking fault nucleation and shear rates. Parameter analysis on alloying additions typically used in commercial superalloys demonstrates which elements have the strongest effect on creep, highlighting how the present model can be used as tool for alloy and microstructure design against dislocation creep.
| Type: | Article |
|---|---|
| Title: | A model for dislocation creep in polycrystalline Ni-base superalloys at intermediate temperatures |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.ijplas.2023.103729 |
| Publisher version: | https://doi.org/10.1016/j.ijplas.2023.103729 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | A. Creep, A. dislocations, B. constitutive behaviour, C. Numerical algorithms, Superalloys |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10175580 |
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