| Summary: | 碩士 === 國立東華大學 === 材料科學與工程研究所 === 89 === Complex quaternary Ti-Si-C-N coatings obtained by atmospheric pressure chemical vapor deposition with TiCl4, SiCl4, C2H2, NH3, and Ar as reactants have been examined in this study. Hardness of the Ti-Si-C-N coating was higher than 11.5 GPa under the experimental conditions, with a maximum value of 20.3 GPa. To exploit the Ti-Si-C-N system, other three systems also were studied: Ti-N, Ti-C-N, and Ti-Si-N.
The experimental results showed the growth rate of TiN varying with temperature and TiCl4 input. The deposits changed the size of the grains with deposition conditions, but mostly kept the 1:0.8 compositional ratio and the hardness values were in the range of 10-13.2 GPa.
The properties of the Ti-C-N coatings were similar to these of the TiN system under the same condition of the flow rate of C2H2 at 3.4 sccm. For the Ti-Si-N system, a similar enhancement of the TiN deposition through chemical assistance has been obtained by adding SiCl4 to the Ti-N system. The films had a thickness of 10-16.6μm, which decreased with the increase in deposition temperature and SiCl4 input. The hardness values were in the range of 11.4-21.5 GPa。
The quaternary films grown at a fast rate (9.0—40μm/hr) had a thickness of 4.5-20μm, which decreased with the increase in deposition temperature and SiCl4 input. It was observed that the amount of SiCl4 at different temperatures had an influence on the microstructure, growth kinetics, and coating composition. These results are explained by the degree of saturation and the SiCl4 protection of TiCl4 from NH3. Mechanical behavior was evaluated by the hardness test. The hardness values were in the range of 11.5-20.3 GPa varying with deposition temperature and SiCl4 input.
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