Abstract
The reactive wetting behaviors of MSA2020, an Fe-based superalloy, and 316L stainless steel in contact with a molten Zn-Al alloy were investigated by the sessile drop method. This investigation led to the following findings. (1) 316L not only suffered considerable wetting, but also reacted with the molten Zn-Al alloy at a higher rate than MSA2020. (2) The contact angle of MSA2020 wet by the molten Zn-Al alloy dropped to an acute angle when the temperature was increased to 500 °C. (3) The surface reaction was found to initiate even though the liquid droplet and substrate were observed as nonwetting (contact angle larger than 90 deg). (4) The reaction mechanisms were identified in three stages. Initially, the Al diffused into the substrate to form an Fe-aluminide layer, which acted as the reaction front. Next, the reaction front penetrated the substrate through inward diffusion of Al. Finally, Zn-rich zones formed behind the reaction front as a result of Al depletion. (5) The alloying constituents (W, Mo, and Cr) in MSA2020 stably segregating on the surface reduced the wettability by molten Zn-Al by covering the reactive sites on the solid-liquid interface.
Original language | English |
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Pages (from-to) | 1382-1391 |
Number of pages | 10 |
Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
Volume | 39 A |
Issue number | 6 |
DOIs | |
State | Published - Jun 2008 |
Externally published | Yes |
Funding
The authors thank the Metaullics Systems (Division of Pyrotek Inc.) for their cooperation to publish these results. Thanks are due to Wheeling-Nisshin, Inc. who helped with supplying the galvanizing zinc. We acknowledge the contributions of Randy Parton, Randy Howell, and Donny McInturff, ORNL, in support of the experimental execution described in this article. The efforts of Mingyang Gong in reviewing this document are also appreciated. This research was sponsored by the United States Department of Energy, Office of Energy Efficiency and Renewable Energy, Industrial Technologies Program, for the United States Department of Energy under Contract No. DE-FC36-04GO14038 and was supported by the Industries of the Future–West Virginia.