Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
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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

  • Kim, Bo-Sik (Graduate Student, Korea Aerospace University) ;
  • Lee, Du-Hyung (Graduate Student, Korea Aerospace University) ;
  • Chang, Si-Young (Department of Materials Engineering, Korea Aerospace University)
  • 김보식 (한국항공대학교 대학원) ;
  • 이두형 (한국항공대학교 대학원) ;
  • 장시영 (한국항공대학교 항공재료공학과)
  • Published : 2009.10.31
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Abstract

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 $MgAl_2O_4$, whereas Mg, MgO, $MgAl_2O_4$ and $Mg_2SiO_4$ 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.

Keywords

References

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