Electrophoretic Painting on AZ31 Mg Alloy Pretreated in Cerium Conversion Coating Solutions Prepared in Ethanol-Water Mixtures

다국어 초록 (Multilingual Abstract)

Electrophoretic painting (E-paint) was prepared on AZ31 Mg alloy samples pretreated in cerium conversion coating (CeCC) solutions with various ratios of ethanol and water mixture and its characteristics, adhesion and corrosion resistance were investigated. It was found that CeCC formed on AZ31 Mg alloy in a CeCC solution without ethanol was partly cracked structure and mainly consisted of Mg(OH)2/MgO, which exhibited weak adhesion with E-painting layer after water immersion test, and low corrosion resistance, as indicated by rapid formation of blisters and paint delamination during salt spray test. The addition of ethanol promoted the growth of a fine nano-crystalline CeO2 layer over the entire substrate surface. The E-paint on AZ31 pretreated in the CeCC solutions with addition of ethanol showed also improved corrosion resistance, as represented by the delayed time for paint delamination and blister formation. The E-paint layers on the CeCC layers formed in solutions containing 50–80 vol% ethanol showed stronger adhesion and better corrosion resistance than those formed on the samples treated in a non-ethanol containing CeCC solution.

참고문헌 (Reference)

1 Y. Kojima, 42 : 1154-, 2001

2 T. G. Harvey, 48 : 248-, 2013

3 P. Yu, 152 : 74-, 2005

4 S. You, 61 : 3778-, 2007

5 L. Lei, 46 : 556-, 2014

6 M. Liu, 51 : 1115-, 2009

7 C. Wang, 51 : 2916-, 2009

8 J. E. Gray, 336 : 88-, 2002

9 X. B. Chen, 67 : 1-, 2011

10 X. B. Chen, 68 : 518-, 2011

11 N. Birbilis, 201 : 4496-, 2007

12 F. Beck, 4 : 1-, 1976

13 R. G. Hu, 73 : 129-, 2012

14 N. V. Phuong, 89 : 91-, 2015

15 L. Besra, 52 : 1-, 2007

16 C. E. Castano, 19 : 69-, 2015

17 C. E. Castano, 246 : 77-, 2014

18 W. Funke, 9 : 29-, 1981

19 C. S. Lin, 152 : 54-, 2005

20 C. S. Lin, 47 : 1020-, 2006

21 M. F. Montemor, 254 : 1806-, 2008

22 L. Ling-jie, 26 : 383-, 2008

23 M. Taheri, 59 : 222-, 2012

24 Y. Luo, 328 : 247-, 2015

25 Nguyen Van Phuong, "Zinc Phosphate Conversion Coatings on Magnesium Alloys: A Review" 대한금속·재료학회 19 (19): 273-281, 2013

26 Basit Raza Fazal, "Formation of Cerium Conversion Coatings on AZ31 Magnesium Alloy" 한국표면공학회 49 (49): 1-13, 2016

27 G. L. Song, "Corrosion Prevention of Magnesium Alloys" Woodhead Publishing Limited 3-63, 2013

28 M. Pourbaix, "Atlas of Electrochemical Equilibria in Aqueous Solutions" National Association of Corrosion Engineers, Pergamon press 644-, 1974

29 "ASTM standard D3359-02, Standard Test Methods for Measuring Adhesion by Tape Test"

30 "ASTM standard B117-03, Standard Practice for Operating Salt Spray (Fog) Apparatus"