Elsevier

Scripta Materialia

Volume 181, May 2020, Pages 30-34
Scripta Materialia

Abnormal precipitation of the μ phase during solution treatment of γ′-strengthened Co-Ni-Al-W-based superalloys

https://doi.org/10.1016/j.scriptamat.2020.02.010Get rights and content

Abstract

Generally, μ phase preferentially precipitates at the place where the refractory elements segregate. However, in this study, the μ phase preferentially formed in the interdendritic regions of Co-Ni-Al-W-based superalloys during solution treatment, while the refractory elements W and Cr segregate to the dendritic cores. The microstructure evolution of the alloy during solution treatment was investigated. It showed that three different mechanisms caused this abnormal precipitation in the interdendritic regions, including primary carbides degeneration, further degeneration of the secondary carbides formed by the Laves phase decomposition, and direct precipitation from the interdendritic regions induced by the Laves phase decomposition.

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Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

Authors would like to thank the financial support of National Key R&D Program of China (No. 2017YFB0702904) and Fundamental Research Funds for the Central Universities (No. FRF-BD-17-017A) and Key-area Research and Development Program of Guangdong Province (No. 2019B010943001).

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