Huang, Wenjun (2007) Grain scale stresses and strains determination by X-ray. PhD thesis Génie mécanique et matériaux, ENSAM 2007ENAM0003 p.142.
Abstract
A new methodology for strain and stress analysis by X ray diffraction (XRD) in single crystal was developed. It can be applied to determine the second order stress (in grain scale) in single and multi-crystal material with non-cubic lattice. This method is based on the method Ortner I. It has introduced the metric tensor G which is deduced from the lattice space measured by XRD. In the developed method, when the crystal reference is non-orthonormal, an orthonormal reference associated with the crystal basis is defined, so all calculation could be done with usual calculation laws. The use of the least square method allows the acquisition of many more measurements than the six absolute necessary. Then a better metric tensor G is calculated and the statistical error is obtained.
This developed method was applied in a bi crystal copper. The experimental results have shown that this method is also effective. The second order residuals stresses for coarse Zn grains in a galvanized coating were determined after annealing. The four coarse grains with different orientations were also characterized and demonstrated the elastic and plastic deformation mechanism in a grain or between the grains during in situ tensile loading. So this method is well able to determine the strains and stresses in grain scale in a mono crystal or multi crystal with any crystalline structure.
| Item Type: | PhD Thesis (PhD) |
|---|
| Thesis Supervisor: | Ji, Vincent |
|---|
| Date: | 06 March 2007 |
|---|
| Board of examiners: | Perriere, Jacques and Tidu, Albert and François, Manuel and Ji, Vincent |
|---|
| Ecole Doctorale: | ED 432 ECOLE DOCTORALE SCIENCES DES METIERS DE L'INGENIEUR |
|---|
| Discipline: | Génie mécanique et matériaux |
|---|
| Collection (Fonds): | ENSAM |
|---|
| Institution: | ENSAM |
|---|
| Subjects: | 4. Materials Science, Mechanics and Mechanical Engineering |
|---|
| Uncontrolled Keywords: | Diffraction des rayons x, Contrainte, Grain, Tenseur métrique, Hexagonal, Galvanisation .recuit, Traction, -ray diffraction, Stress, Grain, Metric tensor, Hexagonal, Galvanization, Annealing, Tensile |
|---|
Statistiques de consultation
Repository Staff Only: edit this item
