TY - CONF
T1 - Influence of Ca-addition amount on corrosion behavior of Ca-added Mg alloys
AU - Shimada, Yuta
AU - Tsunakawa, Mika
AU - Nakamura, Kae
AU - Ishizaki, Takahiro
N1 - Funding Information:
This research was partially supported by a Grant for Advanced Industrial Technology Development from the New Energy and Industrial Technology Development Organization (NEDO) of Japan, a Grant-in-Aid for Young Scientists (B) (No. 16K18249) from the Japan Society for the Promotion of Science, and the Japan Science and Technology Agency (JST), Adaptable and Seamless Technology Transfer Program through Target-driven R&D (A-step: No. AS2815047S).
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved.
PY - 2017
Y1 - 2017
N2 - In recent years, Ca-added Mg alloys has been developed to improve the flame-resistance. Thus Ca-added Mg alloys is expected to be used as the component materials for transport industry and electronic devices because of their safety and lightweight. However, it has been revealed that the corrosion resistance was lowered if Ca was added to Mg alloys. In this study, we aimed to investigate the corrosion behavior of Ca-added Mg alloys in NaCl aqueous solution. FE-SEM and XRD measurements demonstrated that Al-Mn compound and MnAl2O4 were precipitated in AZ61 (0 wt% Ca) and Al2Ca phase was present in AZCa611 (1 wt% Ca) and AZCa612 (2 wt% Ca). And the existence amount of Al2Ca phase in the Ca-added Mg alloys increased with an increase in Ca-addition amount in the AZ61 Mg alloy substrate. It is known that Mg17Al12 (β phase) is present in AZ61, AZCa611, AZCa612. KFM measurements revealed that the surface potential difference between Al2Ca and α-Mg was larger than that between Al-Mg compound, MnAl2O4, or Mg17Al12 (β phase) and α-Mg. The topographic images of the samples after the immersion tests in NaCl aqueous solution demonstrated that Mg(OH)2 was deposited on each precipitate. Therefore, each precipitate acts as a cathode site of local cells. Thus Al2Ca could be one of the causes lowering the corrosion resistance of Ca-added magnesium alloys.
AB - In recent years, Ca-added Mg alloys has been developed to improve the flame-resistance. Thus Ca-added Mg alloys is expected to be used as the component materials for transport industry and electronic devices because of their safety and lightweight. However, it has been revealed that the corrosion resistance was lowered if Ca was added to Mg alloys. In this study, we aimed to investigate the corrosion behavior of Ca-added Mg alloys in NaCl aqueous solution. FE-SEM and XRD measurements demonstrated that Al-Mn compound and MnAl2O4 were precipitated in AZ61 (0 wt% Ca) and Al2Ca phase was present in AZCa611 (1 wt% Ca) and AZCa612 (2 wt% Ca). And the existence amount of Al2Ca phase in the Ca-added Mg alloys increased with an increase in Ca-addition amount in the AZ61 Mg alloy substrate. It is known that Mg17Al12 (β phase) is present in AZ61, AZCa611, AZCa612. KFM measurements revealed that the surface potential difference between Al2Ca and α-Mg was larger than that between Al-Mg compound, MnAl2O4, or Mg17Al12 (β phase) and α-Mg. The topographic images of the samples after the immersion tests in NaCl aqueous solution demonstrated that Mg(OH)2 was deposited on each precipitate. Therefore, each precipitate acts as a cathode site of local cells. Thus Al2Ca could be one of the causes lowering the corrosion resistance of Ca-added magnesium alloys.
KW - Ca-added Mg alloys
KW - Local cells
KW - Surface potential
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M3 - Paper
AN - SCOPUS:85052335980
T2 - Joint European Corrosion Congress 2017, EUROCORR 2017 and 20th International Corrosion Congress and Process Safety Congress 2017
Y2 - 3 September 2017 through 7 September 2017
ER -