Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (44권2호 44-49)

Characteristics of Films Formed on AZ31B Magnesium Alloy by Chemical Oxidation Process in Potassium Permanganate Solution

과망간산칼륨 용액에서 화학적으로 형성된 AZ31B 마그네슘 합금의 피막 특성평가

김민정;김형찬;윤석영;정우창;
Kim, Min-Jeong;Kim, Hyoung-Chan;Yoon, Seog-Young;Jung, Uoo-Chang;

한국생산기술연구원 융합부품소재연구그룹;부산대학교 재료공학부;
Korea Institute of Industrial Technology, Convergence Component Material R&D Group;School of Materials Science and Engineering, Pusan National University;

DOI : 10.5695/JKISE.2011.44.2.044

Abstract

The films formed on AZ31B magnesium alloy were prepared from alkaline solution composed of potassium permanganate and sodium hydroxide. The immersion tests were carried out at the different concentration of sodium hydroxide and pre-treatment method in 5 minute. The morphology and the phase composition of the film were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion behavior of the film in 5.0% NaCl solution was evaluated using potentiodyanmic polarization. Open circuit potential in developing film was examined with time. The thin and transparent film was mainly composed of MgO and $Mg(OH)_2$. The film with the best corrosion resistance was obtained at $70^{circ}C$ bath temperature, 1.6 M concentration of sodium hydroxide and chemical pre-treatment.

Keywords

Magnesium alloy;Oxide film;Corrosion;Chemical oxidation;