1. Kink structures induced in nickel-based single crystal superalloys by high-Z element migration.
- Author
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Sun, Fei, Zhang, Jianxin, Mao, Shengcheng, Jiang, Ying, Feng, Qiang, Shen, Zhenju, Li, Jixue, Zhang, Ze, and Han, Xiaodong
- Subjects
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HEAT resistant alloys , *NICKEL , *CRYSTAL structure , *PHASE transitions , *SCANNING transmission electron microscopy , *CREEP (Materials) , *CHEMICAL kinetics - Abstract
Here, we investigate a new type of kink structure that is found at γ/γ′ interfaces in nickel-based single crystal superalloys. We studied these structures at the atomic and elemental level using aberration corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The core of the dislocation absorbs high-Z elements (i.e., Co and Re) that adopt hexagonal arrangements, and it extrudes elements (i.e., Ni and Al) that adopt face centered cubic (fcc) structures. High-Z elements (i.e., Ta and W) and Cr, which is a low-Z element, are stabilized in body centered cubic (bcc) arrangements; Cr tends to behave like Re. High-Z elements, which migrate and adopt a hexagonal structure, induce kink formation at γ/γ′ interfaces. This process must be analyzed to fully understand the kinetics and dynamics of creep in nickel-based single crystal superalloys. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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