Siska, Filip (2007) Continuum vs. dislocation dynamics modelling of thin films. PhD thesis Sciences et génie des matériaux, Centre des Matériaux P.M. Fourt, ENSMP p.195.
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Abstract
The topic of the thesis is focused on the investigation of the mechanical properties of the copper thin films. These properties are investigated by the finite element method within the framework of classical crystal plasticity and discrete dislocation dynamics.
The elasto-plastic simulations show that the presence of {001} and random oriented grains increases the level of stresses in adjacent {111} oriented grains. Comparison with experimental results shows that used model is not able to predict such high amount of hardening and level of stresses, which are measured during experiments.
The evolution of hardening, plastic microstrain, and global and local surface roughness are investigated by the simulations of cyclic loading of copper polycrystalline aggregates. The hardening tends to saturate as well as the global roughness. The areas of the cumulated residual strain and areas with evolving local roughness are founded. These areas can be precursors of damage.
The other approach in simulations of polycrystalline aggregates is represented by the discrete dislocation dynamics theory. The simulations show that the largest influence is given by the initial source length while the different film thickness does not change the results so much. The highest dislocation activity is observed in the (001) oriented grains and the lowest is in (111) oriented grains.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| Thesis Supervisor: | Forest, Samuel and Gumbsch, Peter |
| Date: | 26 November 2007 |
| Board of examiners: | Thomas, O. and Raabe, D. and Van der Giessen, E. and Fivel, M. and Forest, S. and Gumbsch, P. and Sedlacek, R. and Weygand, D. |
| Ecole Doctorale: | ED 432 ECOLE DOCTORALE SCIENCES DES METIERS DE L'INGENIEUR |
| Discipline: | Sciences et génie des matériaux |
| Collection (Fonds): | ENSMP |
| Institution: | ENSMP |
| Department: | Centre des Matériaux P.M. Fourt |
| Subjects: | 4. Materials Science, Mechanics and Mechanical Engineering |
| Uncontrolled Keywords: | Crystal plasticity, Discrete dislocation dynamics, Finite elements, Thin films, Polycrystals, Plastic deformation, Surface roughness, Couche mince, Propriété mécanique, Polycristal, Plasticité, Théorie dislocation, Rugosité, écrouissage, Méthode élément fini |
Table of content
1. Introduction – crystal plasticity, thin films and size effects
2. Finite element simulations of elastic properties of copper thin films
3. Finite element simulations of the plasticity of copper thin films
4. Mechanical behaviour of copper thin films under cyclic loading
5. Comparison of the simulations with experimental data
6. Discrete dislocation dynamics simulations of multicrystalline aggregates
7. Comparison of the crystal plasticity and DDD simulations
8. Conclusions and prospects
Bibliography
| ID Code: | 3286 |
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| Deposited By: | Odile ADAM |
| Deposited On: | 18 February 2008 |
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