| URN | etd-0312110-135007 | Statistics | This thesis had been viewed 620 times. Download 6 times. |
| Author | Yi-Bin Lin | ||
| Author's Email Address | paul14ice@yahoo.com.tw | ||
| Department | Institute of Mechatronic Engineering | ||
| Year | 2009 | Semester | 1 |
| Degree | Master | Type of Document | Master's Thesis |
| Language | zh-TW.Big5 Chinese | Page Count | 120 |
| Title | The microstructure and mechanical properties evaluation of pulsed DC magnetron sputtered nanocomposite Zr-Si-N thin films | ||
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| Abstract | The ZrN thin films have been widely applied to surfaces of molding tools to prolong their service life due to their excellent mechanical properties. In this study, an asymmetric bipolar DC reactive magnetron sputtering method was adopted to deposit Zr-Si-N thin films on the Si wafer and SKD61 tool steels. The silicon contents of coatings were ranged from 0.05 to 10.4 at.%. The chemical compositions, crystalline structures and binding properties of coatings were analyzed by using the EPMA, XRD and XPS, respectively. The surface and cross-sectional morphologies of thin films were characterized by AFM, SEM and TEM, respectively. The mechanical and tribological properties were evaluated through the nanoindenter and pin-on-disk wear tests, respectively. The corrosion resistance was analyzed by using the potentiostat and AC Impedance in 3.5 wt.% NaCl aqueous solution. The TGA was further adopted to evaluate the high temperature oxidation resistance of coatings at 900oC. It was observed that the surface roughness decreased with increasing silicon contents. The columnar structure disappeared and became a nanocomposite thin film with nano grains embedded in the amorphous matrix when the silicon contents increased. The optimal hardness and coefficient of friction were found on the Zr-Si-N coatings containing low Si contents. On the other hand, the corrosion resistance of SKD61 tool steel was improved tremendously due to the Zr-Si-N coating. The corrosion resistance of Zr-Si-N thin film increased with increasing Si contents, which was closely related to the featureless and amorphous structure of coating. According to the oxidation tests at 900oC, the ZrO2 phase was observed on each coating due to the oxidation of Zr-Si-N coatings. The pure ZrN and low Si contained Zr-Si-N thin films spalled thorough due to the thermal expansion occurred during the high temperature oxidation tests. Meanwhile, the Zr-Si-N coating with high Si contents still adhered on the Si substrates. However, severe crackings were observed on the adhered coatings. |
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| Advisor Committee | |||
| Files | indicate in-campus access at 3 years and off-campus access at 3 years | ||
| Date of Defense | 2010-01-26 | Date of Submission | 2010-03-12 |