The Anodic Role of Ni-Containing LPSO Phases During the Microgalvanic Corrosion of Mg{sub 98}Gd{sub 1.5}Ni{sub 0.5} Alloy

Journal Article · Mon Apr 01 00:00:00 EDT 2019 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-019-04018-X· OSTI ID:22970821

Han, Zhenhua ^[1]; Zhang, Kai ^[2]; Yang, Jun ^[3]; Wei, Ran ^[4]; Liu, Yixin; Zhang, Changjun ^[2]

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1. Xi’an University of Technology, School of Material Science and Engineering (China)
2. Chang’an University, School of Material Science and Engineering (China)
3. Chuanqing Drilling Engineering Co., Ltd, Changqing Downhole Technology Company (China)
4. Zhengzhou University, School of Materials Science and Engineering (China)

In the present study, the corrosion characteristics of cast Mg{sub 98}Gd{sub 1.5}Ni{sub 0.5} alloy with Ni-containing long-period stacking ordered (LPSO) structures were investigated. The results reveal that the Ni-containing LPSO phases were more active than the Mg matrix and preferentially eroded during the immersion process. This behavior indicates that the Ni-containing LPSO phases could have acted as microanodes, in contrast to the cathodic role of the Ni-free LPSO phases in other Mg alloys. Furthermore, the potential difference of approximately 600 mV between the phases accelerated the dissolution rate of the LPSO phase. Corrosion of the Mg matrix also occurred due to the inhomogeneous microstructure of the matrix. The synergetic corrosion between the Ni-containing LPSO phases and the enrichment of Cl{sup −} in the thick corrosion product films dominated the propagation of corrosion, which substantially deteriorated the corrosion resistance and accelerated the corrosion process of the Mg{sub 98}Gd{sub 1.5}Ni{sub 0.5} alloy.

• OSTI ID: 22970821
• Journal Information: Journal of Materials Engineering and Performance, Vol. 28, Issue 4; Conference: AeroMat 2018: 29. Advanced Aerospace Materials and Processes (AeroMat) Conference and Exposition, Orlando, FL (United States), 7-10 May 2018; Other Information: Copyright (c) 2019 ASM International; Country of input: International Atomic Energy Agency (IAEA); ISSN 1059-9495
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
CORROSION PRODUCTS
CORROSION RESISTANCE
MATRICES