E-Thesis 305 views
EFFECT OF SHEAR STRAIN ON METAL DEFORMATION AND MICROSTRUCTURAL EVOLUTION / CYRUS PERSIA
Swansea University Author: CYRUS PERSIA
DOI (Published version): 10.23889/SUthesis.64445
Abstract
Constrained groove pressing (CGP) is a developing method that delivers pure shear during the deformation without any uniaxial strains. This approach of pure shear deformation is relatively new in metal deformation, and this could have significant impact in microstructural tailoring of metallic mater...
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Swansea, Wales, UK
2023
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Prakash, Leo. and Das, Amit. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa64445 |
| Abstract: |
Constrained groove pressing (CGP) is a developing method that delivers pure shear during the deformation without any uniaxial strains. This approach of pure shear deformation is relatively new in metal deformation, and this could have significant impact in microstructural tailoring of metallic material due to its added advantages. Thus, the interest is to perform CGP on key metallic materials having different crystal structure/microstructure and also having industrial relevance. In this context, the key aerospace materials, commercially pure titanium (CP-Ti) and Ti-6Al-4V having hexagonal closed packed crystal structure and Al 7075 and Inconel 718 having cubic (fcc) crystal structure, are selected to carry out CGP. Here, these materials having selected microstructures have groove pressed at different strain rates, ε ̇=0.4 s-1 and ε ̇=0.0004s-1, and undergone a detailed analysis using Electron backscattered diffraction (EBSD) technique. The macrostructure, bulk texture, microstructure, and micro-texture were characterised here to determine the in-build mechanisms of shear deformation and microstructural evolution during CGP. Our results show that slip, twinning, and slip/shear bands play a significant role in the microstructure development during the CGP. The slip and twin induced crystal rotations during CGP also discussed in this study. The crack initiation, propagation and fracture surface also analysed in this project to understand the failure mechanisms, in particular the mode of fracture (brittle, ductile, or mixed). |
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| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC (EP/N509553/1) |