Corrosion Resistance of 55%Al-Zn Alloy Fabricated By Ball Milling and Spark Plasma Sintering

Monday, 10 October 2022: 15:20
Room 306 (The Hilton Atlanta)
M. Nishimoto, T. Kobayashi, I. Muto (Tohoku University), S. Tokuda, Y. Nishida (NIPPON STEEL CORPORATION), and Y. Sugawara (Tohoku University)
Hot-dip 55mass%Al-Zn coated steels show good corrosion resistance because the 55%Al-Zn alloy coating layer acts as a sacrificial anode and protects the steel substrate from atmospheric corrosion.1 The balance between sacrificial behavior and dissolution resistance is important for improving the corrosion protection ability of the Al-Zn coating. In this study, 55%Al-Zn alloy was fabricated by ball milling and spark plasma sintering, and the effect of microstructure on the dissolution behavior of the 55%Al-Zn alloy was investigated.

The 55%Al-Zn alloy specimen was fabricated by ball milling of Al and Zn powders and subsequent spark plasma sintering. The coating layer on the hot-dip 55%Al-Zn coated steel was used to compare the dissolution behavior. The dissolution behavior of 55%Al-Zn alloys was analyzed by galvanic current measurements and polarization measurements in a diluted synthetic seawater.

In the sintered 55%Al-Zn alloy, Zn-rich phases with diameter less than 500 nm were dispersed in the Al matrix. The galvanic current measurements between the sintered 55%Al-Zn alloy and the steel substrate showed that the sintered 55%Al-Zn alloy acted as a sacrificial anode. In the galvanostatic polarization measurements, the potential of the sintered 55%Al-Zn alloy remained lower than that of the hot-dip 55%Al-Zn coating layer.

Reference:

  1. S. Tokuda, I. Muto, Y. Sugawara, M. Takahashi, M. Matsumoto, and N. Hara, Corros. Sci., 129, 126–135 (2017).
See more of: C02 - Corrosion Protection
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See more of: Corrosion Science and Technology
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