Relationship between Microstructure and Exfoliation Corrosion in Mg-14mass%Li-3mass%Al Cold-Rolled Alloy

Abstract:

Relationship between microstructure and exfoliation corrosion in Mg-14mass%Li-3mass%Al cold rolled material were investigated by controlling microstructure using heat treatment. The exfoliation corrosion was exhibited on the specimens with elongated microstructure by cold-rolling. Heat treatment at 200 C only recovery occurred. Recovery and recrystallization were caused by heat treatment at 300 C However, heat treated at 300 C decreased precipitate fraction. Corrosion rate of heat-treated at 200 C decreased by release the residual strain. However, heat treatment at 300 C has lower corrosion resistance than heat-treated at 200 C because it has less precipitate density than as-rolled. Exfoliation corrosion was shown in as-rolled and heat-treated at 200 C. In as-rolled exfoliation corrosion was shown more significant when reduction rate increase. In as-rolled, exfoliation corrosion was shown more significant than heat-treated at 200 C. After heat treatment to change the grain shape from elongated to equiatial, exfoliation was suppressed by the distribution of AlLi phase.

• Periodical: Materials Science Forum (Volume 941)
• Pages: 1743-1747
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.1743
• Online since: December 2018
• Authors: Yutaro Obata, Taiki Morishige, Takayuki Goto, Eiji Nakamura, Toshihide Takenaka
• Keywords: Cold-Rolling, Exfoliation Corrosion, Mg-Li Alloys, Microstructure

References

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