Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9716
標題: 陰極電弧沉積氮化鉻鍍膜性質與微結構之研究
A Study of the Microstructure and Coating Properties of Cathodic Arc Evaporated Chromium Nitrides
作者: 王婉純
Wang, Wan-Chun
關鍵字: Arc evaporation;陰極電弧沉積;CrN;Oxidation;Residual stress;Corrosion;氮化鉻;氧化;殘留應力;腐蝕
出版社: 材料工程學研究所
摘要: 
本研究乃是針對陰極電弧沉積氮化鉻鍍膜之微結構、殘留應力、抗高溫氧化性及氧化前後表面能與抗腐蝕性做探討,以X-光繞射分析儀(XRD)、掃描式電子顯微鏡(SEM)、分析型電子顯微鏡(AEM)高解析度穿透式電子顯微鏡(HRTEM)進行微結構與成分分析,並以衡電位儀(Potentiostat)進行腐蝕情況分析。
對未經氧化的陰極電弧沉積氮化鉻鍍膜進行殘留應力量測,其殘留應力大小為5.05 GPa 。由HRTEM橫截面研究分析結果發現,氮化鉻鍍膜在未氧化前為柱狀結構,其鍍膜厚度為4.1μm,經過氧化後鍍膜本身變為等軸結構,鍍膜上方形成的氧化層為柱狀結構,但鍍膜本身厚度並未改變;由SEM可知經高溫氧化後鍍膜表面的粗糙度隨氧化溫度升高而加大;另外,從XRD與AEM繞射圖得知氧化物以及氮化二鉻相轉換現象發生於溫度500℃,之後隨著氧化溫度越高,氧化及相轉換情況越明顯。
表面能與接觸角有楊式方程式(Young’s equation)的關係,當接觸角越大,鍍膜的表面能就越小,鍍膜與基材之間的脫膜性就越好。實驗以三種溶液量測接觸角後,代入該公式求得鍍膜氧化前後表面能的變化是隨著氧化溫度上生而下降,至氧化溫度500℃以後,鍍膜表面能則呈現持平的狀況。
以基材與氮化鉻、氮化鈦兩種鍍膜進行腐蝕重量損失量測,結果顯示在304不銹鋼上鍍著氮化鈦或氮化鉻鍍膜都具有不錯的抗腐蝕性質,而其中氮化鉻鍍膜又比氮化鈦不易腐蝕;另外取304不銹鋼、未氧化及氧化溫度300℃、500℃的氮化鉻鍍膜進行衡電位儀腐蝕試驗,結果發現鍍膜能有效提升不銹鋼基材的抗蝕性,其中以經過300℃氧化後的鍍膜試片的抗蝕性最佳。

This research is to investigate the microstructure, residual stress, oxidation resistance and corrosion resistance of cathodic arc deposited CrN film. The microstructure and chemical composition of the coatings were analyzed by X-ray diffractometry (XRD), analytical electron microscopy (AEM), high resolution transmission electron microscope (TEM) and scanning electron microscopy (SEM). The corrosion behavior of the coatings were studied by an EG&E 263A potentiostat.
The residual stress in the cathodic arc deposited CrN film was measured to be 5.05 GPa. From cross-section TEM, it is found that the as-deposited CrN has a thickness of 4.1μm, and exhibits columnar structure. The thickness of the CrN film remains the same after oxidation but the CrN phase transfer into a mixture of CrN and Cr2N phases which have equiaxial grains; in addition, a thin oxide film Cr2O3 layer forms near the surface, which has columnar structure. From XRD, SEM and TEM results, it can be found that the extent of phase transformation increases with oxidation temperature.
The surface free energy of CrN films can be calculated from the Young's equation. Experimental results using three different solutions show that the surface energy decreases with increasing temperature below 500℃ and then keep to 800℃.
From the corrosion results, it is found that both CrN and TiN films can protect 304 stainless steel from corrosion in sulfuric acid solution. However, the corrosion resistance of the CrN or TiN-coated carbon steel is less than the bare carbon steel. This result is further confirmed by electrochemical analysis using potential dynamic test.
URI: http://hdl.handle.net/11455/9716
Appears in Collections:材料科學與工程學系

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