Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (52권3호 117-122)

Effects of Na3PO4 Concentration on the Porosity of Plasma Electrolytic Oxidation Coatings Surface on the 6061 Al Alloy, and Subsequent-NaAlO2 Sealing

6061 알루미늄 합금의 플라즈마 전해산화 피막의 표면기공율 및 부식특성에 미치는 Na3PO4 농도 및 NaAlO2 봉공처리의 영향

송의석;김용태;최진섭;
Song, Euiseok;Kim, Yong-Tae;Choi, Jinsub;

인하대학교 화학공학과;
Department of Chemistry and Chemical Engineering, Inha University;

DOI : 10.5695/JKISE.2019.52.3.117

Abstract

In this study, surface porosity and corrosion resistance of PEO coatings prepared on the 6061 Al alloy were investigated in terms of sodium phosphate ($Na_3PO_4$) concentrations in an alkaline solution and $NaAlO_2$ sealing. The surface morphologies of the PEO coatings clearly show that the coatings film formed in $9g;L^{-1}$ had the lowest porosity. The $NaAlO_2$ sealing was found to remove micropores and cracks existing on the surface of PEO coatings. As a result, the $NaAlO_2$ sealing resulted in the movement of corrosion potential toward more positive value and lower corrosion current density.

Keywords

6061 Al alloy;Plasma electrolytic oxidation;Sodium phosphate;$NaAlO_2$ sealing;