마그네슘 합금의 아노다이징 및 특성연구 = Properties of magnesium alloys prepared by the anodizing method

국문 초록 (Abstract)

마그네슘은 일반적인 금속 중 가장 큰 화학적 활성을 가지므로, 이에 따라 마그네슘 합금도 내식성을 갖기 위한 전처리가 필요하다. 본 연구는 여러 가지 유기산으로 전처리하여 양극 산화된 마그네슘 합금의 내식성에 대하여 조사하였다. 유기산은 옥살산(Oxalic acid), 구연산(Citric acid), 초산(Acetic acid)을 사용하였다. 생성된 피막의 표면에 대한 morphology와 조성 그리고 전기화학적 물성을 평가하는 실험을 진행하였다. 양극 산화된 표면의 morphology는 SEM을 통해 관찰하였고, EDS 분석 결과 산화 피막은 Mg, O, Al로 이루어져 있음을 확인하였다. 산화 피막의 내식성을 조사하기 위해 3.5 wt.% NaCl용액에서 동전위 분극시험(potentiodynamic polarization test)과 electrochemical impedance spectroscopy(EIS)를 분석하여 AZ91D Mg alloy의 내식성을 알 수 있었다. 이 결과에서 구연산과 초산으로 전처리한 양극 산화 피막이 내식성을 향상시켰음을 알 수 있었다.

다국어 초록 (Multilingual Abstract)

Since Magnesium has the highest chemical activity among commonly used metal, its alloys require the surface treatment to enhance its corrosion resistance. In this study, the corrosion resistance of AZ91D magnesium alloy by anodizing was investigated according to various organic acid picklings as the surface pretreatment. The organic acids used for this investigation include oxalic acid, citric acid and acetic acid. Examination has been carried out on the anodic film for morphology, composition and corrosion resistance. The morphology of the anodized surface was observed using SEM. The main elements of the anodic film of AZ91D Mg alloy are Mg, O, and Al by EDS analysis. The corrosion resistance of the coating for AZ91D Mg alloy substrates in 3.5 wt.% NaCl solutions was found by potentiodynamic polarization, electrochemical impedance spectroscopy in open circuit potential monitoring. The electrochemical results showed that the anodizing of the AZ91D Mg alloy by the acid pickling pretreatment of the organic acid such as citric acid and acetic acid improved the corrosion protection.

참고문헌 (Reference)

1 김명환, "비크롬계 인산-과망간산 용액을 이용한 AZ31 마그네슘 합금의 산처리에 따른 화성 피막의 특성 평가" 한국표면공학회 43 (43): 73-79, 2010

2 G. L. Song, "The electrochemical corrosion of pure magnesium in 1N Nacl" 39 : 955-, 1997

3 Y. Ma, "Systematic study of the electrolytic plasma oxidation process on a Mg alloy for corrosion protection" 494 : 296-, 2006

4 Y. S. Gal, "Synthesis of Poly(phenylacetylene) catalyzed by WCl3-EtAlCl2 and its electro-optical and electrochemical properties" 17 : 7-, 2011

5 Y. Zhang, "Study on the environmentally friendly anodizing of AZ91D magnesium alloy" 161 : 36-, 2002

6 J. E. Gray, "Protective coatings on magnesium and its alloys" 336 : 88-, 2002

7 A. Abdel Aal, "Protective coating for magnesium alloy" 43 : 2947-, 2008

8 H. Tang, "Preparation and characterization of HA microflowers coating on AZ31 magnesium alloy by micro-arc oxidation and a solution treatment" 264 : 816-, 2013

9 W. Li, "Non-sparking anodization process of AZ91D magnesium alloy under low AC voltage" 178 : 417-, 2013

10 A. Dey, "Microstructural corrosion and nanomechanical behaviour of ceramic coatings developed on magnesium AZ31 alloy by micro arc oxidation" 39 : 3313-, 2013

11 B. L. Mordike, "Magnesium properties - application - potential" A302 : 37-, 2001

12 T. S. Lee, "Electrochemical corrosion properties of CeO2 -containing coatings on AZ31 magnesium alloys prepared by plasma electrolytic oxidation" 62 : 104-, 2012

13 H. Duan, "Electrochemical corrosion behavior of composite containings of sealed MAO film on magnesium alloy AZ91D" 51 : 2898-, 2006

14 P. B. Srinivasan, "Effect of plasma electrolytic oxidation treatment on the corrosion and stress corrosion cracking behaviour of AM50 magnesium alloy" 494 : 401-, 2008

15 U. C. Nwaogu, "Effect of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet" 52 : 2143-, 2010

16 M. Laleh, "Effect of alumina sol addition to micro-arc oxidation electrolyte on the properties of MAO coatings formed on magnesium alloy AZ91D" 496 : 548-, 2010

17 N. A. Mahallawy, "AZ91 Magnesium alloys: anodizing of using environmental friendly electrolytes" 1 : 62-, 2011