Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9351
標題: 鉻介層對低合金鋼上氮化鉻硬質膜性質之影響研究
The Effect of Cr-interlayer on the Properties of CrN coating on Low Alloy Steels
作者: 郭錦政
CHENG, KUO.CHIN
關鍵字: CrN;氮化鉻;corrosion;cavitation;腐蝕;穴蝕;硬質膜
出版社: 材料工程學研究所
摘要: 
以物理氣相沈積法合成的氮化鉻鍍膜,一般具有兩種常見之結構,其分別為岩鹽NaCl結構的CrN以及六方晶系結構的β-Cr2N。鍍膜中的氮化鉻相組成與製程控制參數息息相關;氮化鉻硬質膜相對於常用的氮化鈦硬膜具有高附著性、高抗蝕、抗氧化與耐磨耗等特性,是以在近幾年內逐漸被廣泛使用與研究之主因。
陰極電弧電漿沈積法(Cathodic Arc Evaporation,CAE) 的蒸氣離化率非常高;鍍膜成長速率快,均勻性佳、結構緊密、規則且附著性良好,而且鍍膜成長溫度低,並可藉助活化反應方式被覆高品質之陶瓷硬膜。
本研究所採用之製程技術為電鍍法(Electroplating)與陰極電弧沈積系統(CAE , cathodic arc evaporation system)。而被覆單一的電鍍鉻鍍層(Cr/AISI 4140)、單一的氮化鉻鍍層(CrN/AISI 4140)與以電鍍鉻為介層再被覆氮化鉻之複合鍍層(CrN/Cr/AISI 4140)等三種表面改質薄膜。探討分析鍍膜之型態、硬度、附著性、磨潤行為、抗穴蝕性與耐腐蝕性等。
研究結果顯示複合鍍膜因鉻介層之緣故,明顯出現非常強的CrN(220)優選方向,在微硬度上為三組鍍膜中之最高(2315 Hv);其附著性略優於單一氮化鉻鍍膜。在磨耗試驗中,複合鍍膜與單一氮化鉻鍍膜兩者在巨觀的磨耗試驗中無法看出兩者微觀之差異,同具有非常良好的耐磨耗特性,與鍍膜優選方向無直接之關係。
在穴蝕試驗結果,可以發現三種鍍膜皆有助於降低穴蝕對底材破壞之程度;在腐蝕性環境中,除了穴蝕的純機械力破壞外,還帶有腐蝕因子形成之伽凡尼效應而導致鍍膜破壞加速的情況。在直流極化試驗中,可知有被覆鍍膜之試片都有較底材為低的腐蝕電流,並且有鈍化效果,顯示鍍膜在此環境中有增強抗腐蝕能力的效果,其中又以複合鍍膜具有最低之腐蝕電流(7.815μA/cm2),耐蝕性最佳。

Chromium nitride coatings exhibit good mechanical , corrosion and oxidation protection properties and can have various orientations.The aim of this paper is to evaluate the corrosion protection of steel substrates by depositing CrN and Cr hard coatings performed by cathodic arc evaporation and electroplating . The transition metal nitrides CrN are deposited by using a cathodic arc evaporation technology , while the intermediate chromium layer is deposited by an electroplating process.The mutilayer coating (CrN/Cr/AISI4140) is compare with two single layer coating (Cr/AISI4140、CrN/AISI4140) with the aim of improving the corrosion resistance , mechanical properties.
Cathodic arc evaporation is a powerful and common used technology . For such hard coating deposition it offers a wide range of advantages which will be recalled in this paper. The chromium nitride coatings are fairly dense with a microcolumnar morphology. Adhesion is as good as usually obeserved with this technology.
The mutilayer CrN coating is characterized by a strong [220] orientation and the single layer CrN coating is in fact a mixture of Cr2O3 and CrN.We studied the electrochemical 、 mechanical behaviour of CrN/Cr system , and underlined the beneficial improvement of corrosion 、 mechanical behaviour due to the intermediate chromium layer.
URI: http://hdl.handle.net/11455/9351
Appears in Collections:材料科學與工程學系

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