Mechanical Properties Measurement of Submicrometer Ti-Ni Shape MemoryAlloys Thin Films
碩士 === 國立中興大學 === 精密工程學系所 === 105 === Ti-60 at%Ni thin films with thickness of 700nm were deposited on silicon nitride with and without chromium interlayer. Static and dynamic mechanical properties of these films were investigated by bulge test and using SEM, XRD for internal structure and crystalli...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2017
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| Online Access: | http://ndltd.ncl.edu.tw/handle/85089316001411275904 |
| Summary: | 碩士 === 國立中興大學 === 精密工程學系所 === 105 === Ti-60 at%Ni thin films with thickness of 700nm were deposited on silicon nitride with and without chromium interlayer. Static and dynamic mechanical properties of these films were investigated by bulge test and using SEM, XRD for internal structure and crystalline phase orientation. It was found that the Ti-Ni film has the lowest residual stress and the highest Young’s modulus with the adhesion of chromium interlayer. The addition of chromium interlayer between film and silicon nitride introduces R phase transformation in room temperature. Microstructure analysis revealed that the surface trenches will be significantly reduced when the film with chromium interlayer, which indicates that chromium interlayer can minimize the stress evolution during film deposition. Thermal cycling stress evolution test results showed that chromium interlayer has the function of buffering TiNi and SiNx thermal mismatch. In addition, the thermal cycling bulge test method was used to measure the thermal expansion coefficient of unknown films. Also, the fatigue test showed that the interlayer layer of Cr can enhance the fatigue strength of TiNi films.
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