1. Unveiling the transpassive film failure of 3D printing transition alloys
- Author
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Guo, Pengfei, Lin, Xin, Macdonald, Digby D, Ter-Ovanessian, Benoît, Liu, Jianrui, Song, Guangling, Zhang, Yufeng, Ren, Yongming, Lan, Hongbo, and Huang, Weidong
- Subjects
Superalloys ,Polarization ,TEM ,Anodic dissolution ,Anodic films ,Transpassivity ,Civil Engineering ,Materials Engineering ,Mechanical Engineering ,Energy - Abstract
The failure of transpassive films on transition metal alloys was investigated. The results show that the failure of the transpassive film on 3D printing nickel-based superalloy in flowing NaNO3 solution is dominated by self-induced cracking of the film on niobium-segregated phases and the erosion-induced degradation on the film assisted by cation vacancy condensation at the metal/barrier layer interface. Secondary passivation induces the formation of a transpassive film, the nature of which has been debated for decades. The findings are consistent with a bi-layer structure comprising a point-defective barrier layer that grows into the substrate alloy and a precipitated outer layer.
- Published
- 2022