本論文以調整正負電流比例對6061鋁合金進行微弧氧化鍍製ZrO2/Al2O3陶瓷氧化膜之影響，並對膜層生長機制、相結構變化與電漿行為作探討。在實驗中使用鋯酸鹽類混合鋁酸鹽類兩種混合電解液系統，先利用定電壓模式鍍製較穩定的膜層後再調整正負電流比例得到不同正負電流比之氧化陶瓷膜，觀察其表面形貌與斷面形貌可以發現，當正負電流較高或是平均時，產生的形貌多為放電通道較明顯的火山孔形貌，且膜層厚度可達100μm以上，但也容易因為後期電壓過大使得膜層有破壞；正負電流比例越小，膜層產生的etching效應越強，使得膜層表面產生的孔洞會越多且越明顯，膜層厚度也受到破壞而減少，甚至有完全被侵蝕不見的情形發生，接著再擷取厚度較好的1,1、1.0與0.91比例之試片進行時段的觀察，從膜層的增加與減少可以發現有生長與破壞特別顯出的時段，表示膜層在各時段中並不只有生長階段，為生長與破壞同時進行。尤其在0.91比例試片部分，約三十分鐘到四十分鐘左右會有正電壓突然下降的情況發生，此時弧光與實驗的反應會變得比較緩慢且微弱，從擷取的時段SEM圖可以發現此時的膜層生長速率也下降，但此階段生成之膜層也相對較緻密且穩定，在後期電壓回復穩定上升時，對於膜層的破壞性也相對下降，膜層能夠維持較好的品質。
　　XRD結果顯示，以各時段來說前期會有較多的氧化鋁和氧化鋯互相混合的相成分，後期則多為氧化鋯相為主，並且是含鋁的ｔ相氧化鋯，以維克氏硬度檢測發現，含鋁的氧化鋯相硬度值並不高，約為6061基材的三至四倍，但也由於韌性的提升，與基材的對角線壓痕比較起來，破壞性明顯下降很多，顯示氧化鋯的韌性使得裂縫的延伸被吸收，能夠阻止裂縫擴展轉入脆性斷裂模式，材料抵抗裂縫延伸的能力增強。
　　電漿測量發現鈉離子的反應會相對其他元素明顯，而隨著鍍製時間越長，表面弧光強度越高其峰值的強度也會越明顯，後期產生的OH峰值在後期會因為變成氣體逸散因此會有下降的趨勢，鉀離子也會隨著時間峰值也越明顯，但至鍍製時間結束，並沒有太大的下降趨勢，與EDS元素對比，可以知道鉀元素在電漿態時進入膜層內的比例較少，顯示主要的反應不集中於鉀與鈉元素離子上。但原本期望看到的鋁離子與鋯離子沒有較明顯的峰值呈現，因此對於鍍製前期由氧化鋁相為主、後期以氧化鋯相鍍製為主的推論目前仍沒有更多的論點可證實，在光譜實驗上的部份可能需要再去多做探討與改進。

In this paper,we try to adjust the positive and negative current ratio in plasma electrolytic oxidation(PEO) ceramic coating on 6061 alumibnum alloy. The electrolytes system contain NaAlO2 and K2ZrF6. The compositions, structure, morphologies and plasma behavior of the ZrO2/Al2O3 oxide coationgs formed in different working parameters were determined by scanning electron microscopy(SEM), X-ray diffraction(CRD), energy dispersive spectroscopy(EDS) and spectrometer.
In the first part, using voltage constant to create a steable oxide coating layer and then adjust the positive and negative curent ratio(1.1、1.0、0.91、0.83、0.71 and 0.63) in reaction. When positive and negative current ratio is higher than 0.91, the oxide coatings thinkness can grow to more than 100μm and show volcanic morphology and denser. But, there are also easily become destroy when the voltage rises in ratio 1.1 and 1.0. On the other side, the positive and negative current ratio smaller than 0.83, the etching effect will stronger and make more pore on the surface. Coating layer will reduce or disappear because of damage.
In the second part, we compare ratio 1.1, 1.0 and 0.91 data which thickness are higher than others. We can see increase and decrease in the coating layer. It shows
growth and destruction at the reaction time. Especially in the ratio 0.91 part, the voltage suddenly drop about thirty miniutes to fourty minutes. The arc and reaction will become slowly and weakly in this time. But the oxide film also find relarively dense and stable in the slowly reaction.
XRD analysis shows that the coatings contains ZrO2 and Al2O3 phase. It has been discovered from the surface 10 minutes to one hour. And zirconium oxide will increase with time(aluminum reduce). Tha average hardness value is 400Hv, which is not higher than pure alumina or zirconium. However, the toughness improvement made destructive decreased. It can make crack extension, not brittle fracture.
　　Plasma measurements found that the reaction of sodium ions can significantly relative to other elements spectrum. We will see OH peak and potassium ions peak after 30 minutes. And OH peak become weakly because of gas escape to the air. The potssium ions peak found obviously, which still clear and strong util the end of reation. It shows the potssiium ions not mainly reaction in electrolyte. Unfortunately, we expect to see the aluminum ions and zirconium ions spectrum peak, but is still not obviously. On the part of experimental spectrum may need to improve.

[1] Robert E. Sanders, Jr. Technology Innovation in Aluminum Products, 2001 February • JOM
[2]Mardov, G.A. and G.V. Markova, The formation method of anodic electrolytic condensation. SU52961,1976.
[3]Kurze, P.K. and H.G. Schneider, Application fields of ANOF layers and composites. Cryst .Res. Technol., 1986. 21: p. 1603.
[4] WenBin Xue, ZhiWei Deng, RuYi Chen, TongHe Zhang, Hui Ma, ”Microstructure and properties of ceramic coatings produced on 2024 aluminum alloy by microarc oxidation”, Journal of Materials Science 36, 2615-2619, 2001.
[5] Yong-Jun Oh, Jung-Il Mun, Jung-Hwan Kim, ”Effects of alloying elements on microstructure and protective properties of Al2O3 coatings formed on aluminum alloy substrates by plasma electrolysis”, Surface & Coatings Technology 204, 141-148, 2009.
[6]H. Y. Zheng, Y. K. Wang, B. S. Li, G. R. Han, ”The effects of Na2WO4 concentration on the properties of microarc oxidation coatings on aluminum alloy”, Materials Letters 59, 139-142, 2005.
[7] Yang Guangliang, Lu Xianyi, Bai Yizhen, Cui Haifeng, Jin Zengsun, ”The effects of current density on the phase composition and microstructure properties of micro-arc oxidation coating”, Journal of Alloys and Compounds 345, 196-200, 2002.
[8]徐榮,利用雙極脈衝電源微弧氧化法探討占空比和頻率對於7075-T6 鋁合金表面氧化膜層之影響,大同大學材料所碩士論文,2009
[9] WENBIN XUE, ZHIWEI DENG, RUYI CHEN, TONGHE ZHANG, HUI MA
Key Laboratory for Radiation Beam Technology and Materials Modification,Institute of Low Energy Nuclear Physics, Beijing Normal University, Microstructure and properties of ceramic coatings produced on 2024 aluminum alloy by microarc oxidation,JOURNAL OF MATERIALS SCIENCE 36 (2001) 2615–2619
[10]陳文杰,邱傳聖,7075鋁合金經微弧氧化處理後之耐磨耗特性 ,南亞學報第二十九期,私立元智大學機械工程學系研究所
[11] A.L. Yerokhin, X. Nie, A. Leyland, A. Matthews, S.J. Dowey, Review
Plasma electrolysis for surface engineering,122(1999)73-93,Russia&UK
[12] F. Me´cuson, T. Czerwiec, T. Belmonte, L. Dujardin, A. Viola, G. Henrion, Diagnostics of an electrolytic microarc process for aluminium alloy oxidation, Surface & Coatings Technology 200 (2005) 804– 808, France
[13] L.O. Snizhko , A.L. Yerokhin , A. Pilkington , N.L. Gurevina ,
D.O. Misnyankin , A. Leyland , A. Matthews, Anodic processes in plasma electrolytic oxidation of aluminium in alkaline solutions, Electrochimica Acta 49 (2004) 2085–2095.
[14] Mohannad M.S. Al Bosta ,⇑, Keng-Jeng Mab, Hsi-Hsin Chien, The effect of MAO processing time on surface properties and low temperature infrared emissivity of ceramic coating on aluminium 6061 Alloy, Infrared Physics & Technology60, 2013, 323-334.
[15]Jun-Hua Wanga,b,c, Mao-Hua Dua,∗∗, Fu-Zhu Hanb,c,∗, Jing Yang, Effects of the ratio of anodic and cathodic currents on thecharacteristics of micro-arc oxidation ceramic coatings on Al alloys, Applied Surface Science 292 (2014) 658– 664.
[16] Shi-Gang Xin, Li-Xin Song, Rong-Gen Zhao, Xing-Fang Hu, ”Composition and thermal properties of the coating containing mullite and alumina”, Materials Chemistry and Physics 97, 132-136, 2006.
[17] Vahid Dehnavi, Xing Yang Liu, Ben Li Luan, David W. Shoesmith, Sohrab Rohani, ”Phase transformation in plasma electrolytic oxidation coatings on 6061 aluminum alloy”, Surface & Coatings Technology 251, 106-114, 2014.
[18] Kai WANG, Bon-Heun KOO, Chan-Gyu LEE, Young-Joo KIM, Sung-Hun LEE, Eungsun BYON, ”Effects of electrolytes variation on formation of oxide layers of 6061 Al alloys by plasma electrolytic oxidation”, Trans. Nonferrous Met. Soc. China 19, 866-870, 2009.
[19] Nitin P. Wasekar, A. Jyothirmayi, L.Rama Krishna, G. Sundararajan, ”Effect of Micro Arc Oxidation Coatings on Corrosion Resistance of 6061-Al Alloy”, Journal of Materials Engineering and Performance, Volume 17(5), 708-713, 2008.
[20]翁海峰, 陳秋龍, 蔡珣, 鮑明東, ”脈衝占空比對純鋁微弧氧化膜的影響”, 表面技術, 第34卷, 第5期, 2005.
[21] Vahid Dehnavi, Ben Li Luan, David W. Shoesmith, Xing Yang Liu, Sohrab Rohani, ”Effect of duty cycle and applied current frequency on plasma electrolytic oxidation (PEO) coating growth behavior”, Surface & Coatings Technology 226, 100-107, 2013.
[22] Junming Li, Hui Cai, Bailing Jiang, ”Growth mechanism of black ceramic layers formed by microarc oxidation”, Surface & Coatings Technology 201, 8702-8708, 2007.
[23] F. Jaspard-Mecuson, T. Czerwiec, G. Henrion, T. Belmonte, L. Dujardin, A. Viola, J. Beauvir, ”Tailored aluminium oxide layers by bipolar current adjustment in the Plasma Electrolytic Oxidation (PEO) process”, Surface & Coatings Technology 201, 8677-8682, 2007.
[24]K.Nishizawa, T. Miki, H. Fukaya, Y. Masuda, K. Suzuki, K. Kato, “Surface morphology control of zirconia thin films prepared using novel photochromic molecules.” Thin Solid Films, 516,2635-2638,2008.
[25] Y.J. Liu, J.Y. Xu , W. Lin , C. Gao , J.C. Zhang and X.H. Chen, “EFFECTS OF DIFFERENT ELECTROLYTE SYSTEMS ON
THE FORMATION OF MICRO-ARC OXIDATION CERAMIC
COATINGS OF 6061 ALUMINUM ALLOY”, Rev. Adv. Mater. Sci. 33 (2013) 126-130.
[26] Mingqi Tang, Weiping Li, Huicong Liu, Liqun Zhu, “Preparation Al2 O3 /ZrO2 composite coating in an alkaline phosphate electrolyte containing K2ZrF6 on aluminum alloy by microarc oxidation”, Applied Surface Science 258 (2012) 5869–5875.
[27]李沛傑, ”以油酸分散膠體配合氣氛加熱製造奈米氧化鋯粉末之研究”, 2002.
[28] Yuanyuan Yan, Yong Han and Juanjuan Huang, “Formation of Al 2 O 3 –ZrO 2 composite coating on zirconium by micro-arc oxidation”, Scripta Materialia 59 (2008) 203–206.
[29] Wenbin Xue1, Chao Wang1, Zhiwei Deng1,2, Ruyi Chen1, Yongliang Li2 and Tonghe Zhang, “Evaluation of the mechanical properties of microarc oxidation coatings and 2024 aluminium alloy substrate” Journal of Physics: Condensed Matter, Volume 14, Number 44,2002.
[30] Wenbin Xue, Qingzhen Zhu, Qian Jin , Ming Hua, “Characterization of ceramic coatings fabricated on zirconium alloy by plasma electrolytic oxidation in silicate electrolyte”, Materials Chemistry and Physics 120 (2010) 656–660.
[31] 鍾喬森,微弧氧化法鍍製ZrO2/Al2O3陶瓷氧化膜於6061鋁合金之機制探討,2015.
[32] E. Matykina, R. Arrabal, A. Mohamed, P. Skeldon *, G.E. Thompson,” Plasma electrolytic oxidation of pre-anodized aluminium.” Corrosion Science 51 (2009) 2897–2905.
[33] P. Laboratory, "NIST ： Atomic Spectra Database," National Institute of Standards and Technology, USA.
[34] Weng Hai-Feng, Chen Qiu-long, Cai Xun, Bao Ming-Dong, Surface Technology, 34 (2005) 59-62
[35] WO 99/31303, A.S. Shatrov, Method for producing hard protection coatings on articles made of aluminium alloys, publ. 24.06.99.
[36] Wang Y. M., Jiang B.L., Lei T.Q., Guo L.X., Surface and Coatings Technology, 201 (2006) 82-89.
[37] Keiji Watanabe, Masatoshi Sakairi , Hideaki Takahashi, *, Shinji Hirai ,Sadae Yamaguchi, Formation of Al–Zr composite oxide films on aluminum by sol–gel coating and anodizing, Journal of Electroanalytical Chemistry 473 (1999) 250–255.
[38] ZHANG Xin-Meng, CHEN Dong-Fang, GONG Chun-Zhi , YANG Shi-Qin, TIAN Xiu-Bo, Modulation Effects of K 2 ZrF 6 Additive on Microstructure and Heat Resistance of Micro-arc Oxide Coatings Fabricated on LY12 Aluminum Alloy. Journal of Inorganic Materials, Vol. 25 No. 8(2010) 865-870.