과망간산칼륨 용액에서 화학적으로 형성된 AZ31B 마그네슘 합금의 피막 특성평가

• Published in: Biuletyn Uniejowski Vol. 44; no. 2; pp. 44 - 49
• Main Authors: 김민정(Min Jeong Kim), 김형찬(Hyoung Chan Kim), 윤석영(Seog Young Yoon), 정우창(Uoo Chang Jung)
• Format: Journal Article
• Language: Korean
• Published: 한국표면공학회 2011
• Subjects: 기계공학; Corrosion; Chemical oxidation; Magnesium alloy; Oxide film
• ISSN: 1225-8024; 2299-8403; 2288-8403

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.