由於鎂及其合金之優異的物理及機械性質，如低密度、高比強度、良好的鑄造與焊接能力、優良的電與熱之傳導性、高尺寸穩定性、以及良好的電磁遮蔽性，使得近年來對於其之應用範圍越發廣泛，特別是在於汽車、航太、通信及電腦元件範圍之應用，其所占之比例漸漸升高。但如一般所知鎂及其合金之耐蝕性差，特別是在酸性以及鹽水環境之下，使得鎂合金無法當作結構材料使用於腐蝕性的環境中，進而限制鎂合金的應用範圍及發展，故為增加鎂合金之應用範圍，賦予抗腐蝕能力，使其在腐蝕環境下仍不會失去優異之物理及機械性質是極其重要之一環。
本研究使用常壓電漿噴射束(APPJ)沉積法，以四乙氧基矽烷(Tetraethoxysilane, TEOS)作為前驅物，以不同之載氣流量沉積無機氧化矽薄膜於AZ91D鎂合金基材表面，藉以提升鎂合金耐蝕能力。利用X射線光電子能譜儀(ESCA)及傅立葉紅外線光譜儀(FT-IR)分析薄膜材料特性，結果顯示隨著作為載氣之氧氣流量的上升，所鍍之薄膜約趨近於無機二氧化矽薄膜之性質。其後以電化學之動電位極化曲線以及阻抗頻譜分析之測量表明，相較於原始之鎂合金AZ91D試片，經過鍍膜後之試片其具有較高之腐蝕電位以及更低之腐蝕密度，此結果證實可利用沉積氧化矽薄膜於試片表面之方式，提升鎂合金AZ91D基材之抗腐蝕能力。
最後，以在1800 sccm載氣流量下所鍍試片，於3.5 wt%之NaCl水溶液中進行七十二小時之浸泡測試，而其結果顯示在經過七十二小時之浸泡後，所鍍薄膜試片之抗腐蝕能力仍然高於原始之鎂合金AZ91D試片，故表示本研究所鍍之氧化矽可有效的提升鎂合金AZ91D之抗腐蝕能力，為鎂合金之防腐蝕處理提供一有效且具有成本效益之方法。

Magnesium and its alloys are used in a broad range of applications including automobile, aerospace, communications and computer components owing to their excellent physical and mechanical properties, such as low density, high specific strength, good cast and weld ability, excellent electrical and thermal conductivity, high dimensional stability, and good electromagnetic shielding characteristics. Unfortunately, magnesium alloys possess lower corrosion resistance, especially in acidic environments and salt-water conditions. The ability to increase the corrosion resistance of magnesium and its alloys is crucial to increase the range of applications. To improve the fault, it is important to impart a high corrosion resistance without losing the superior physical and mechanical properties.
This study focused on the development of atmospheric pressure plasma jet (APPJ) system using tetraethoxysilane (TEOS)/O2 plasma under atmospheric pressure to deposit SiOx films on the surface of magnesium alloys in order to improve the resistance to corrosion. The material characterization results using X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy indicated that with increased O2 carried gas, the deposited thin films by APPJ were of inorganic SiOx nature. The potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) measurements show that SiOx films coated on AZ91D alloys have more positive corrosion potential and lower corrosion current density than AZ91D substrates, indicating the corrosion resistance of AZ91D can be improved by depositing SiOx film on its surface. Finally, inorganic SiOx film at an O2 carrier gas flow rate of 1800 sccm after immersion in 3.5 wt.% NaCl solution for 72 h showed the better corrosion resistance than AZ91D alloy. The APPJ-deposited SiOx films represent an interesting alternative for improving the anti-corrosion performance of various materials in a cost-effective approach.
Keywords: magnesium alloys, Atmospheric pressure plasma deposition technique, inorganic-like silicon oxide (SiOx) thin films, anti-corrosion layers

[1] 陳俊欽, "鋁鋅複合噴覆塗層對AZ31 鎂合金表面性質之影響," 大同大學材料工程研究所碩士論文, 2003.
[2] 陳樹友, "鎂合金於AlCl3-EMIC離子液體中鍍鋁層之耐蝕性研究," 成功大學材料科學及工程學系碩士論文, 2007.
[3] H. Inoue, K. Sugahara, A. Yamamoto, H. Tsubakino, "Corrosion rate of magnesium and its alloys in buffered chloride solutions," Corrosion Science, vol. 44, pp. 603-610, 2002.
[4] C. R. S. Mathieu, J. Hazan, P. Steinmetz, "Corrosion behaviour of high pressure die-cast and semi-solid cast AZ91D alloys," Corrosion Science, vol. 44, pp. 2737-2756, 2002.
[5] C. D. Yim K. S. Shin, "Semi-solid processing of Magnesium alloys," Materials transactions, vol. 44, pp. 558-561, 2003.
[6] A. L. Rudd, C. B. Breslin, F. Mansfeld, "The corrosion protection a orded by rare earth conversion coatings applied to magnesium," Corrosion Science vol. 42, pp. 275-288, 2000.
[7] C. Blawert, W. Dietzel, E. Ghali, G. Song, "Anodizing treatments for Magnesium alloys and their effect on corrosion resistance in various environments," Advanced Engineering Materials, vol. 8, pp. 511-533, 2006.
[8] Y. I. Choi, S. Salman, K. Kuroda, M. Okido, "Synergistic corrosion protection for AZ31 Mg alloy by anodizing and stannate post-sealing treatments," Electrochimica Acta, vol. 97, pp. 313-319, 2013.
[9] F. Chen, H. Zhou, B. Yao, Z. Qin, Q. Zhang, "Corrosion resistance property of the ceramic coating obtained through microarc oxidation on the AZ31 magnesium alloy surfaces," Surface and Coatings Technology, vol. 201, pp. 4905-4908, 2007.
 
[10] Y. K. Pan, C. Z. Chen, D. G. Wang, X. Yu, Z. Q. Lin, "Influence of additives on microstructure and property of microarc oxidized Mg–Si–O coatings," Ceramics International, vol. 38, pp. 5527-5533, 2012.
[11] L. Bárdos H. Baránková, "Cold atmospheric plasma: Sources, processes, and applications," Thin Solid Films, vol. 518, pp. 6705-6713, 2010.
[12] S. H. Yang, C. H. Liu, C. H. Su, H. Chen, "Atmospheric-pressure plasma deposition of SiOx films for super-hydrophobic application," Thin Solid Films, vol. 517, pp. 5284-5287, 2009.
[13] A.M. Mahajan, L.S. Patil, D.K. Gautam, "Influence of process parameters on the properties of TEOS–PECVD-grown SiO2 films," Surface & Coatings Technology, 188–189 (2004) 314– 318.
[14] 莊東漢, "材料破損分析," 五南圖書出版公司, 2007.
[15] A.S. Handbook, ASM International, (1999) 3-43.
[16] H.Proffit, "Magnesium and Magnesium Alloys," AMS Hanbook, vol. 2., pp. 798-799
[17] A.K. Dahle, Y.C. Lee, M.D. Nave, P.L. Schaffer, D.H.StJohn, "Development of the as-cast microstructure inmagnesium-Aluminium alloys," Journal of Light Metals, vol. 1、PP.61-72，2001.
[18] R.Ambat, N.N.Aung, W.Zhou, "Evaluation of microstructural effects on corrosion behaviour of AZ91D magnesium alloy, " Corrosion Science, vol.42, P.1433，2000.
[19] G.Song, L.Amanda, Bowles, H.David, StJohn, "Corrosion resistance of aged die cast magnesium alloy AZ91D, "Materials Science and Engineering, A366, P.74, 2004.
[20] G.Song, A.Atrens, X.Wu B.Zhang, "Corrosion behaviour of AZ21、AZ501 and AZ91 in sodium chloride, " Corrosion Science, vol.40, P.1769, 1998.
 
[21] 陳學翰 and 王建義, "Be、Sc 微量添加對LAZ1110 機械性質之影響," 鎂合金產業通訊, vol. 40 期, pp. 34-42, 民國97.
[22] N. S. McIntyre C. Chen, "Role of impurities on Mg surface under ambientexposure conditions," Corrosion science, vol. 40, p. 1697, 1998.
[23] 柯賢文, "腐蝕及其防制," 全華科技圖書股份有限公司, 1994.
[24] K. Nisancioglu, O. Lunder, T. Aune, presented at 47th World Magnesium Conference, Cannes, France 1990.
[25] G. Song, A. Atrens, M. Dargusch, Corros. Sci. 41 (1999) 249–273.
[26] G.L. Song, A. Atrens, Adv. Eng. Mater. 5 (2003) 837–858.
[27] 田福助 吳溪煌, "電化學-理論與應用," 高立圖書有限公司, 1988.
[28] A. L. Yerokhin, L.O.Snizhko, N.L.Gurevina, A.Leyland, A.Pilkington, A.Matthews, "Spatial characteristics of discharge phenomena in plasma electrolytic oxidation of aluminum alloy," Surface and Coatings Technology, vol. 177-178, pp. 779-783, 2004.
[29] Y. Ma, X. Nie, D. O. Northwood, H. Hu, " Corrosion and erosion properties of silicate and phosphate coatings on magnesium," Thin Solid Films, vol. 469–470, pp. 472–477, 2004.
[30] 陳仲宜, "淺談微弧氧化技術在輕金屬表面處理之應用," 2007.
[31] Y.M. Wang, F.H. Wang, M.J. Xu, B. Zhao, L.X. Guo, J.H. Ouyang, " Microstructure and corrosion behavior of coated AZ91 alloy by microarc oxidation for biomedical application, " Applied Surface Science 255 (2009) 9124–9131.
[32] K. Huber, "Anodic formation of coatings on magnesium, Zinc and cadmium," Journal of the electrochemical society, vol. 10, pp. 376-382, 1953.
[33] O. Khaselev and J. Yahalom, "The anodic behavior of binary Mg-Al alloys in KOH-Aluminate solution," Corrosion science, vol. 40, pp. 1149-1160, 1998.
[34] M. Takaya, "Anodizing of magnesium alloys in KOH-Al(OH)3 solutions," Aluminum, vol. 65, pp. 1244-148, 1989.
[35] S. J. Kim, R. Ichino, M. Okido, "Characterization of anodic films formed on
Mg-Al alloys in alkaline bath," Materials science forum, vol. 3427, pp. 426-432, 2003.
[36] Ch. Voulgaris, E. Amanatides, D. Mataras, S. Grassini, E. Angelini, F. Rosalbino, "RF power and SiOxCyHz deposition efficiency in TEOS/O2 discharges for the corrosion protection of magnesium alloys," Surface and Coatings Technology, vol. 200, pp. 618-6622, 2006.
[37] H. Hoche, J. Schmidt, S. Groß, T. Troßmann, C. Berger, "PVD coating and substrate pretreatment concepts for corrosion and wear protection of magnesium alloys," Surface and Coatings Technology, vol. 205, pp. S145-S150, 2011.
[38] I. Vlassiouk, P. Fulvio, H. Meyer, N. Lavrik, S. Dai, P. Datskos, et al., "Large scale atmospheric pressure chemical vapor deposition of graphene," Carbon, vol. 54, pp. 58-67, 2013.
[39] Y. T, "Method for plating magnesium alloy," pp. 209-212, 2007.
[40] A. Grill, "Cold plasma in materials fabrication-from fundamentals to application,"
IEEE Press, NY, 1994.
[41] 陳克紹 and 曹永偉, "薄膜技術," 金文書局, 台北, 1986.
[42] B. Chapman, "Glow Discharge: Sputtering and Plasma Etching," Wiley-Interscience, New York, 1980.
[43] J. R. Roth, "Industrial Plasma Engineering," Principles, of Physics Publishing, London, vol. 1, 1995.
[44] S. Kanazawa, M. Kogoma, T. Moriwaki, S. Okazaki, "Stable glow plasma at atmospheric pressure," Journal of Physics D: Applied Physics, vol. 21, pp. 836-840, 1988.
 
[45] T. Yokoyama, M Kogoma, T Moriwaki, S. Okazaki, T. Yokoyama, "The mechanism of the stabilisation of glow plasma at atmospheric pressure," Journal of Physics D: Applied Physics, vol. 23, pp. 1125-1128, 1990.
[46] J. Y. Jeong, S. E. Babayan, J. P. V. J. Tu, R. F. Hicks, G. S. Selwyn, "Etching materials with an atmospheric-pressure plasma jet," Plasma Sources Science and Technology, vol. 7, pp. 282–285, 1998.
[47] S. E. Babayan, J. Y. Jeong, V. J. Tu, A. Schutze, M. Moravej, G. S. Selwyn, et al.,
"Deposition of silicon dioxide films with a non-equilibrium atmospheric-pressure plasma jet," PLASMA SOURCES SCIENCE AND TECHNOLOGY, vol. 10, pp. 573–578, 2001.
[48] J. Park, I. Henins, H. W. Herrmann, G. S. Selwyn, R. F. Hicks, "Discharge phenomena of an atmospheric pressure radio-frequency capacitive plasma source," Journal of Applied Physics, vol. 89, p. 20, 2001.
[49] W. C. S.Y. Moon, "Driving frequency effects on the characteristics of atmospheric pressure capacitive helium discharge," Applied physics letters, vol. 93, 2008.
[50] M. Goldman and N. Goldman, "Corona discharges," Gaseous Electronics,Eds. New York: Academic vol. 1, pp. 219-290, 1978.
[51] U. Kogelschatz, "Filamentary, Patterned, Diffuse Barrier Discharges," IEEE Transactions on Plasma Science, vol. 30, pp. 1400-1408, 2002.
[52] J. R. Roth, "Industrial Plasma Engineering Philadelphia," Taylor & Francis Group 1, 1995.
[53] M. Hur S. H. Hong, "Comparative analysis of turbulent effects on thermal plasma characteristics inside the plasma torches with rod- and well-type cathodes," Journal of Physics D: Applied Physics, vol. 35, pp. 1946-1954, 2002.
 
[54] N. Jidenko, C. Jimenez, F. Massines, J. P. Borra, "Nano-particle size-dependent charging and electro-deposition in dielectric barrier discharges at atmospheric pressure for thin SiOx film deposition," Journal of Physics D: Applied Physics, vol. 40, pp. 4155-4163, 2007.
[55] R. Morent, N. D. Geyter, S. V. Vlierberghe , P. Dubruel, C. Leys, E. Schacht, "Organic–inorganic behaviour of HMDSO films plasma-polymerized at atmospheric pressure," Surface and Coatings Technology, vol. 203, pp. 1366–1372, 2009.
[56] W. A. Zisman, "Relation of the equilibrium contact angle to liquid solid constitution," vol. 43, pp. 1-51, 1964.
[57] D.Y. Kwok and A. W. Neumann, "Contact angle measurement contact angle interpretation," Advances in Colloid and Interface Science, vol. 81, pp. 167-249, 1999.
[58] S. Siboni, C. Della Volpe, D. Maniglio, M. Brugnara, "The solid surface free energy calculation; II. The limits of the Zisman and of the "equation-of-state" approaches," J Colloid Interface Sci, vol. 271, pp. 454-72, Mar 15 2004.
[59] P. Zdenka, S. K. Karin, S. S. Majda, K. Tatjana, "Determining the surface free energy of cellulose materials with the powder contact angle method," Textile Research Journal, vol. 74, pp. 55-62, 2004.
[60] http://sindatek.com/Bmyl.htm.
[61] F. Grzegorzewski, S. Rohn, A. Quade, K. Schröder, J. Ehlbeck, O. Schlüter, et al.,
"Reaction chemistry of 1,4-Benzopyrone derivates in non-equilibrium Low-temperature plasmas," Plasma Processes and Polymers, vol. 7, pp. 466-473, 2010.
[62] 簡郡邑, "以常壓電漿輔助化學氣相沉積氧化矽薄膜於AZ31 鎂合金上之抗腐蝕特性研究, " 國立台灣科技大學 機械工程系碩士學位論文, 2013
 
[63] N. Koshizaki, H. Umehara, T. Oyama, “ XPS characterization and optical properties of Si/SiO2, Si/Al2O3 and Si/MgO co-sputtered films”, Thin Solid Films 325 (1998) 130–136.
[64] L. J. Ward, W. C. E. Schofield, J. P. S. Badyal A. J. Goodwin P. J. Merlin, “Atmospheric Pressure Glow Discharge Deposition of Polysiloxane and SiOx Films” , Langmuir 2003, 19, 2110-2114.
[65] J.F. Moulder, W.F. Stickle, P.E. Sobol, K.D. Bomben, Handbook of X-ray Photoelectron Spectroscopy, Physical Electronics, Inc., 1995.
[66] Chou J S Lee S C, “Effect of porosity on infrared‐absorption spectra of silicon dioxide”, J. Appl. Phys. 77 1805, 1995
[67] G R Nowling, M Yajima, S E Babayan, M Moravej, X Yang, W Hoffman R F Hicks, “Chamberless plasma deposition of glass coatings on plastic”, Plasma Sources Sci. Technol. 14 477–484 , 2005
[68] V. Raballand, J. Benedikt, A. v. Keudell, "Deposition of carbon-free silicon dioxide from pure hexamethyldisiloxane using an atmospheric microplasma jet," Applied Physics Letters, vol. 92, p. 091502, 2008.
[69] Y. Ding, Q. Pan, J. Jin, H. Jia, H. Shirai, "Silicon oxide synthesized using an atmospheric pressure microplasma jet from a tetraethoxysilane and oxygen mixture," Thin Solid Films, vol. 518, pp. 3487-3491, 2010.
[70] X. Y. Xu, L. Li, S. G. Wang, L. L. Zhao, T. C. Ye, "Deposition of SiOx ilms with a capacitively-coupled plasma at atmospheric pressure," Plasma Sources Science and Technology, vol. 16, pp. 372-376, 2007.
[71] G. Socrates, "Infrared characteristic group frequencies — tables and charts," John Wiley and Sons Ltd., pp. 241-246, 2001.
[72] Marek Nocun, Katarzyna Cholewa-Kowalska, Maria Ła˛czka, "Structure of hybrids based on TEOS-cyclic forms of siloxane system, " Journal of Molecular Structure 938 (2009) 24–28˙
[73] Chou J S Lee S C, “Effect of porosity on infrared‐absorption spectra of silicon dioxide”, J. Appl. Phys. 77 1805, 1995
[74] Alfred Grill Deborah A. Neumayer, " Structure of low dielectric constant to extreme low dielectric constant SiCOH films: Fourier transform infrared spectroscopy characterization, " Journal of Applied Physics 94, 6697 (2003); doi: 10.1063/1.1618358
[75] A Delimi, Y Coffinier, B Talhi, R Boukherroub, Sabine Szunerits, "Investigation of the corrosion protection of SiOx-like oxide films deposited byplasma-enhanced chemical vapor deposition onto carbon steel," Electrochimica Acta. 55 (2010) 8921–8927
[76] L. Cui, A. N. Ranade, M. A. Matos, L. S. Pingree, T. J. Frot, G. Dubois, R. H. Dauskardt, "Atmospheric Plasma Deposited Dense Silica Coatings on Plastics," ACS Appl. Mater. Interfaces. 6587−6598, 2012, 4