Browse > Article
http://dx.doi.org/10.5695/JKISE.2020.53.2.59

Formation Behavior and Properties of PEO Films on AZ91 Mg Alloy in 0.1 M NaOH + 0.05 M NaF Solution Containing Various Na2SiO3 Concentrations  

Kwon, Duyoung (Surface Technology Division, Korea Institute of Materials Science)
Song, Pung-Keun (Department of Materials Science and Engineering, Pusan National University)
Moon, Sungmo (Surface Technology Division, Korea Institute of Materials Science)
Publication Information
Journal of the Korean institute of surface engineering / v.53, no.2, 2020 , pp. 59-66 More about this Journal
Abstract
Effects of Na2SiO3 concentration added into 0.1 M NaOH + 0.05 M NaF solution on the formation behavior and properties of PEO films on AZ91 Mg alloy were investigated under 1200 Hz of alternating current (AC) by voltage-time curves, in-situ observation of arc generation behavior and measurements of film thickness, surface roughness and micro vickers hardness. In the absence of Na2SiO3 in the 0.1 M NaOH + 0.05 M NaF solution, about 4 ㎛ thick PEO film was formed within 1 min and then PEO film did not grow but white spots were formed by local burning. Addition of Na2SiO3 up to 0.2 M caused more increased formation voltage and growth of PEO film with uniform generation of arcs. Addition of Na2SiO3 from 0.2 M to 0.4 M showed nearly the same voltage-time behavior and uniform arc generation. Addition of Na2SiO3 more than 0.5 M resulted in a decrease of formation voltage and non-uniform arc generation due to local burning. PEO film growth rate increased with increasing added Na2SiO3 concentration but maximum PEO film thickness was limited by local burning if added Na2SiO3 concentration is higher than 0.5 M. Surface roughness of PEO film increased with increasing added Na2SiO3 concentration and appeared to be proportional to the PEO film thickness. PEO film hardness increased with increasing added Na2SiO3 concentration and reached a steady-state value of about 930 HV at more than 0.5 M of added Na2SiO3 concentration.
Keywords
AZ91 Mg alloy; Plasma electrolytic oxidation; $Na_2SiO_3$ concentration; Burning;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 Carsten Blawert, Wolfgang Dietzel, Edward Ghali, and Guangling Song, Anodizing Treatments for Magnesium Alloys and Their Effect on Corrosion Resistance in Various Environments, Advanced Engineering Materials 8.6 (2006) 511-533.   DOI
2 C.E. Barchiche, D. Veys-Renaux and E. Rocca, A better understanding of PEO on Mg alloys by using a simple galvanostatic electrical regime in a KOH-KF-$Na_3PO_4$ electrolyte, Surface and Coatings Technology 205 (2011) 4243-4248.   DOI
3 J. Liang, P. Bala Srinivasan, C. Blawert, M. Stormer and W. Dietzel, Electrochemical corrosion behaviour of plasma electrolytic oxidation coatings on AM50 magnesium alloy formed in silicate and phosphate based electrolytes, Electrochimica Acta 54 (2009) 3842-3850   DOI
4 R. Arrabal, A. Pardo, M.C. Merino, M. Mohedano, P. Casajus, E. Matykina, P. Skeldon and G.E. Thompson, Corrosion behaviour of a magnesium matrix composite with a silicate plasma electrolytic oxidation coating, Corrosion Science 52 (2010) 3738-3749.   DOI
5 Sungmo Moon, Yeajin Kim, and Cheolnam Yang. Effect of NaOH Concentration on the PEO Film Formation of AZ31 Magnesium Alloy in the Electrolyte Containing Carbonate and Silicate Ions, Kor. Inst. Surf. Eng. 50 (2017) 308-14.
6 Stojadinovic, S., Vasilic, R., Radic-Peric, J, and Peric, M., Characterization of plasma electrolytic oxidation of magnesium alloy AZ31 in alkaline solution containing fluoride, Surface and Coatings Technology 273 (2015) 1-11.   DOI
7 Xijin Li and Ben Li Luan, Discovery of Al2O3 particles incorporation mechanism in plasma electrolytic oxidation of AM60B magnesium alloy, Materials Letters 86 (2012) 88-91.   DOI
8 Xiaopeng Lu, Mauricio Schieda, Carsten Blawert, Karl Ulrich Kainer, Mikhail L and Zheludkevich, Formation of photocatalytic plasma electrolytic oxidation coatings on magnesium alloy by incorporation of TiO2 particles, Surface and Coatings Technology 307 (2016) 287-291.   DOI
9 Xiaopeng Lu, Carsten Blawert, Yuanding Huang, Henry Ovri, Mikhail L. Zheludkevich and Karl Ulrich Kainer, Plasma electrolytic oxidation coatings on Mg alloy with addition of SiO2 particles, Electrochimica Acta 187 (2016) 20-33.   DOI
10 S. Moon and J. Kim, Effect of $Na_3PO_4$ Concentration on The Formation Behavior of PEO films on AZ31 Mg Alloy, Kor. Inst. Surf. Eng. 52 (2019) 265-274.
11 S. Moon and Y. Jeong, Generation mechanism of microdischarges during plasma electrolytic oxidation of Al in aqueous solutions, Corrosion Science 51 (2009) 1506-1512.   DOI
12 D. Kwon and S. Moon, Effects of NaOH Concentration on the Structure of PEO Films Formed on AZ31 Mg Alloy in $PO_{4}{^{3-}}\;and\;SiO_{3}{^{2-}}$ Containing Aqueous Solution, Kor. Inst. Surf. Eng. 49 (2016) 46-53.   DOI