Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Effects of Nitrate Electrolyte as the MAO process for Ceramic Coating treatments of AZ31 alloy

MAO법을 이용한 산화피막처리에서 질산염 전해액성분 첨가에 따른 AZ31합금의 표면코팅 특성

  • Cho, Young-Hee (Dept. of Advanced Material Eng., Kongju National University) ;
  • Jang, Kyong-Soo (Dept. of Advanced Material Eng., Kongju National University) ;
  • Park, Sei-He (Dept. of Advanced Material Eng., Kongju National University) ;
  • Lee, Ho-Jeong (Dept. of Advanced Material Eng., Kongju National University) ;
  • Lee, Tae-Haeng (Dept. of Advanced Material Eng., Kongju National University)
  • 조영희 (공주대학교 신소재공학부) ;
  • 장경수 (공주대학교 신소재공학부) ;
  • 박세희 (공주대학교 신소재공학부) ;
  • 이호정 (공주대학교 신소재공학부) ;
  • 이태행 (공주대학교 신소재공학부)
  • Received : 2012.09.20
  • Accepted : 2012.10.11
  • Published : 2012.10.31
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Abstract

AZ31 Mg alloy were coated by Macro Arc Oxidation(MAO) with 3 types of electrolyte and various coating times at 4A/$cm^2$. The Surface morphology of coatings became lager pores and surface crack initiated as the coating time increased. The thickness and micro-hardness of coatings increased as the coating time increased. also. The phase of coatings on AZ31 alloy consisted of MgO, $Mg_2SiO_4$ and $MgAl_2O_4$ oxides. The salt spray corrosion resistance of coated AZ31 alloys revealed excellent corrosion resistance in 5% NaCl solution for 168hr.

MAO 법을 이용하여 전류밀도 4A/$cm^2$조건에서 3종류의 전해액과 코팅시간에 따라 AZ31 마그네슘 합금을 산화피막 처리하였다. 코팅시간이 길어짐에 따라 코팅층의 표면형상은 기공이 더욱 커지고, 표면에 균열이 발생하기도 하였다. 또한 코팅시간이 길어짐에 따라 코팅층의 두께와 경도(HV)값은 증가하였다. AZ31합금의 코팅층 상들은 MgO, $Mg_2SiO_4$ 그리고 $MgAl_2O_4$ 산화물로 이루어졌다. 산화코팅된 AZ31합금을 5% NaCl 용액에서 168시간동안 염수분무실험결과 우수한 내식성을 나타냈다.

Keywords

References

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