System Development of Stress Image Microscopy (SIM)
| Autor: | Jui-JieChen, 陳瑞杰 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 Residual stresses arising by non-uniform cooling, welding and mechanical processing are known to have influence on materials’ mechanical properties. Thus, it is of importance to measure accurately residual stresses especially in high-tech industry. However, conventional methods of residual stress measurement, such as using X-ray diffraction and drilling method, are limited by their spatial resolution. Therefore, in this study, residual stress was measured by electron backscattered diffraction (EBSD) technique due to its high spatial resolution. In this study we developed a “Stress Image Microscope” which was based on EBSD technique. We built the first prototype of EBSD hardware at one hand and developed the program of stress measurement based on EBSD technique at the other hand for the first time in Taiwan. The home-made EBSD system includes a phosphorescent screen detector, optical lens and a CCD camera. In order to test the EBSD system, decrease in the distance between the phosphorescent screen and the specimen from 55 to 40 mm leads to improving the mean angular deviation from 0.850 to 0.520. In the second part of this study the resolution of stress measurement with EBSD was investigated. At fixed working distance the electron beam movement resulted the pixel displacement of 0.02458 (pixel/μm) at 100 times magnification and 0.02336 (pixel/μm) of 2000 times magnification. Obviously, the beam movement effect didn’t have a large influence on the pixel displacement. In addition the residual stress measurement was applied for through silicon via structure in silicon. The home-made software of stress measurement has an axis displacement resolution of 2.97x10-3 (radian/pixel), stress resolution to 0.1MPa and the strain resolution to 10-5. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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