| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 96 === In this study a technique of deposition by plasma assisted pulsed laser in atmospheric pressure is proposed. The formation of diamond-like carbon (DLC) film has been investigated. This approach is made to accelerate the ablated carbon particles by a high temperature plasma torch, then the kinetic energy of the carbon particle can be increased to form the sp3 atomic structure of the carbon by the plasma flow.
The influences of the plasma flow have been examined by numerical analysis and experimental observation. In the numerical analysis, the electromagnetic fields and the distribution of velocity and temperature on plasma flow have been solved by a set of magnetohydrodynamics (MHD) equations with the software FLUENT. The effects on the plasma flow at various parameters, such as electric current and inlet pressure, are discussed in this study. The plasma assisted pulsed laser deposition method was used to deposit DLC film on the steel substrate at atmospheric pressure with the argon gas flow in experiment. According to the results of the carbon film inspected by the Raman spectroscopy, it reveals that the intensity ratio of the D-band to G-band (Id/Ig) of the carbon film can be reduce to 0.513 by the implementation of plasma flow, therefore the DLC film was solidly formed. The adhesive strength of the DLC film was characterized by the scratch test, it can be seen that the critical load of the film is about 19 N, which is acceptable in comparison with other approaches.
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