本研究探討以電漿化學氣相沉積法（plasma-enhanced chemical vapor deposition）將類鑚碳（Diamond-like carbon, DLC）披覆於316不銹鋼、鈦、黃銅及碳鋼表面後於靜態及動態3.5 wt% NaCl水溶液中的電化學性質。該DLC鍍層以X光繞射分析儀（X-ray diffraction）、拉曼光譜分析儀（Raman scattering spectroscopy）分析鍍膜之原子排列（Atomic arrangement）及化學結構（chemical structure），並以掃描式電子顯微鏡（scanning electron microscopy）觀察鍍膜之表面形貌及其橫截面微觀組織，鍍膜在3.5 wt% NaCl水溶液中的電化學性質則是藉由開路電位量測、動電位極化曲線測試來取得。
研究結果指出，不論基材為何種材料，所批覆的DLC均為非結晶相；當基材為不銹鋼或鈦時，DLC之缺陷面積較少且與基材介面之間附著程度較佳。靜態的電化學測試結果顯示，經披覆DLC鍍膜的試片其開路電位較未披覆之基材提升約數百個微伏特（mV），並可將陽極電流密度降低數個數量級（order）。動態環境則是利用旋轉電極控制轉速為2500 rpm下進行3.5 wt% NaCl電化學性質測試，其結果顯示，不論是基材或經披覆DLC的試片，於動態環境中的腐蝕電流密度均較靜態系統有所增加，顯示動態系統中的，試片表面的質量輸送（mass transport）及流體應力（flow stress）現象都有增強。
此外，為了解動態流體條件對316不銹鋼、鈦、黃銅及碳鋼基材耐蝕性質之影響，本研究在控制不同旋轉電極轉速於3.5 wt% NaCl水溶液中進行電化學量測。其結果顯示，當轉速增加時，基材的腐蝕電位（corrosion potential, Ecorr）會向較正的電位偏移，腐蝕電流（corrosion current density, icorr）及電荷遷移阻抗（charge transfer resistance）均會降低，亦即材料的腐蝕阻抗（corrosion resistance）會隨轉速增加而降低，其主要原因為當轉速增加時，於旋轉電極表面的能斯特介面層（Nernst boundary layer）較薄，使得氧氣的質量傳送現象及溶液（bulk）與基材界面間離子的質量傳送現象均有加速所致。
而由於DLC之電化學性質與披覆之良率及DLC/基材介面特性呈正相關，其結果也顯示電化學技術（如開路電位及動電位極化曲線量測）可做為鑑定DLC鍍膜品質的一種測試方法。同時，本研究利用旋轉電極進行靜態及動態3.5 wt% NaCl水溶液環境的電化學性質量測，其研究結果將可用探討不同流體（流體物質或流速等）對電極表面造成的影響。

Diamond-like carbon (DLC) coatings have been deposited onto 316SS, titanium, brass and carbon steel by plasma-enhanced chemical vapor deposition, respectively. Atomic arrangement, chemical structure, surface morphology and cross-section microstructure of the DLC coatings were examined by X-ray diffraction, Raman scattering spectroscopy and scanning electron microscopy. The electrochemical behaviors of the DLC coatings in 3.5 wt% NaCl solution were investigated by performing open circuit potential (OCP) measurement and potentiodynamic polarization test. The experimental results showed that properly deposited DLC coatings could cause an increase of OCP by hundreds of millivolts and a reduction of anodic current density by several orders of magnitude as compared to that of the substrate. The results also demonstrated that electrochemical techniques could be used as tools to detect the soundness of the DLC coating by examining OCP and polarization curve, which varied with the form of defect and depended on the type of substrate.
After that, we have investigated effect of hydrodynamic flow condition at rotation speed 2500rpm using rotating disk electrode (RDE) on the electrochemical corrosion behavior of DLC-Coated specimens. The electrochemical behaviors of the DLC coatings in 3.5 wt% NaCl solution were investigated by performing open circuit potential (OCP) measurement, electrochemical impedance resistance analysis and potentiodynamic polarization curves determination, same condition with under static condition. The experimental results showed that corrosion current density was increased for either bare or coated substrates under hydrodynamic condition. The effects of enhanced mass transport and flow stress on corrosion behavior of various metallic materials were demonstrated.
We also investigated the influence of hydrodynamic conditions on the corrosion of bare substrates (316SS, brass, carbon steel, and Titanium) in 3.5 wt% NaCl solution at different rotation speeds using rotating disk electrode (RDE). It was found that the corrosion potential, Ecorr, shifted toward more positive potential, corrosion current density, icorr , increased and charge transfer resistance decreased as the rotation speed increased, indicating a decrease in corrosion resistance of material. The increase of rotation rate, causing the relatively high rate of oxygen mass transport to the RDE is due to thinner Nernst boundary layer. This behavior could be attributed to the enhanced the mass transport from bulk to the metal surface in high rotation rates.

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