pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (29권5호 233-237)
Effect of Electrolyte on Mechanical and Corrosion Properties of AZ91 Cast Magnesium Alloy Coated by Plasma Electrolytic Oxidation Method
플라즈마 전해 산화처리한 AZ91 주조마그네슘합금의 기계적 및 부식 특성에 미치는 전해질의 영향
Bo-Sik Kim, Du-Hyung Lee, Si-Young Chang*
Graduate Student of Korea Aerospace University, *Korea Aerospace University
The effect of electrolyte on mechanical and corrosion properties of AZ91 magnesium alloy by plasma electrolytic oxidation (PEO) method was investigated. The coating layers formed in the silicate and the aluminate electrolytes showed porous structures. The small pores were randomly distributed on the coatings formed in aluminate electrolyte while the coatings formed in silicate electrolyte showed much bigger pores. In the aluminate electrolyte, the coatings were composed of Mg, MgO and MgAl2O4, whereas Mg, MgO, MgAl2O4 and Mg2SiO4 were identified in the coatings formed in silicate electrolyte. The hardness of coatings in the silicate electrolyte was higher than that of coating grown in the aluminate electrolyte. The AZ91 alloy coated in the silicate electrolyte had higher tensile strength and elongation than that coated in the aluminate electrolyte. In addition, the coatings formed in the silicate electrolyte showed much better corrosion resistance compared to the coatings formed in the aluminate electrolyte.
Plasma electrolytic oxidation, Electrolyte, AZ91 alloy, Hardness, Tensile Property, Corrosion resistance.
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