에어로졸 증착법에 의한 YSZ 코팅된 AA1050 알루미늄 합금의 전기화학적 부식 특성 |
유현삼, 임태섭, 류정호1, 박동수1, 홍성현 |
서울대학교 재료공학부 1재료연구소 기능세라믹연구그룹 |
Electrochemical Corrosion Properties of YSZ Coated AA1050 Aluminium Alloys Prepared by Aerosol Deposition |
Hyun-Sam Ryu, Tae-Seop Lim, Jung-Ho Ryu1, Dong-Soo Park1, Seong-Hyeon Hong |
WCU Hybrid Materials Program, Department of Materials Science and Engineering and Center for Iron and Steel Research, Seoul National University 1Functional Ceramics Research Group, Korea Institute of Materials Science (KIMS) |
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ABSTRACT |
Yttria stabilized zirconia (YSZ) coating was formed on AA1050 Al alloys by aerosol deposition (AD), and its electrochemical corrosion properties were investigated in 3.5 wt% NaCl and 0.5M $H_2SO_4$ solutions. The crack-free, dense, and ~5 ${mu}m$ thick YSZ coating was successfully obtained by AD. The as-deposited coating was composed of cubic-YSZ nanocrystallites of ~10 nm size. The potentiodynamic test indicated that the YSZ coated Al alloy had much lower corrosion current densities (2 nA/$cm^2$) by comparison to uncoated sample and exhibited a passive behavior in anodic branch. Particularly, a pitting breakdown potential could not be identified in $H_2SO_4$. EIS tests revealed that the impedance of YSZ coated sample was ${sim}10^6{Omega}cm^2$ in NaCl and ${sim}10^7{Omega}cm^2$ in $H_2SO_4$, which was about 3 or 4 orders of magnitude higher than that of uncoated sample. Consequently, the corrosion resistance of Al alloy had been significantly enhanced by the YSZ coating. |
Key words:
AA1050 aluminium alloy, Aerosol deposition, Corrosion property, NaCl, $H_2SO_4$ |
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