| Summary: | 碩士 === 龍華科技大學 === 化工與材料工程系碩士班 === 105 === If the tribological behavior was improved, the applications of titanium could be increased. The deposition of the diamond coating can resolve this problem. However, due to the different lattice constant of the two materials, it is difficult to grow adherent thin diamond layers on titanium. The deposition of the well adherent diamond coating is important on titanium.
In this study, a well-adhered nanocrystalline diamond (NCD) film was successfully deposited on pure Ti substrate by using a microwave plasma assisted chemical vapor deposition system in the environment of Ar, CH4 and H2 gases. Morphology, surface roughness, hardness, wettability, and adhesion were studied by characterizing the sample with Raman spectrum-meter, X-ray diffraction, Field emission scanning electron microscopy, Atomic Force Microscopy, Nano-Indenter, contact angle instrument and Rockwell-C tester, respectively.
The characteristic peaks of the NCD were found in Raman spectra and the (111) peak of diamond was observed in XRD pattern, indicating that the deposited film was (111) preferred orientation NCD film. The NCD film hardness increases up to 49GPa, roughness decreases to 23 nm and the contact angle increases to 92°, with increasing hydrogen concentration in CVD plasma atmosphere. Of particular interest in the adhesion analysis was the exceptional adhesion of approximately 14 μm-thick diamond film to the titanium substrate as observed by indentation testing up to 150 kg load.
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