Atomic Interaction Mechanism of Heterogeneous Nucleation in Mg-Al Alloys Achieved by Carbon Inoculation
Theoretical calculations were performed to explore the heterogeneous nucleation mechanism of an Mg-Al alloy inoculated by a carbon-containing substance. The valence electron structure and cohesive energy of Al<sub>4</sub>C<sub>3</sub> and Al<sub>2</sub>C<sub>...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-05-01
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| Series: | Metals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4701/15/6/594 |
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| Summary: | Theoretical calculations were performed to explore the heterogeneous nucleation mechanism of an Mg-Al alloy inoculated by a carbon-containing substance. The valence electron structure and cohesive energy of Al<sub>4</sub>C<sub>3</sub> and Al<sub>2</sub>C<sub>2</sub>Mg crystals were calculated using the empirical electron theory of solids and molecules (EET). The binding energy of Al1-C2 bonds in Al<sub>4</sub>C<sub>3</sub> is about 140.6 kJ/mol with a lower number of equivalent bonds. Correspondingly, the binding energy of Al2-C2 bonds is about 129.6 kJ/mol, and the number of equivalent bonds is high. The weak combination of the Al1 and C2 atomic layers might lead to the breaking of Al<sub>4</sub>C<sub>3</sub>, and then the remaining strong skeleton of the Al2-C2 structure will facilitate the formation of Al<sub>2</sub>C<sub>2</sub>Mg. Based on the calculating results, the atomic interaction mechanism to account for the heterogeneous nucleation of α-Mg by C inoculation is elaborated, which also provides insights into the essence of the overheating process and the influence of Al and Mn elements on the refinement efficiency of Al<sub>2</sub>C<sub>2</sub>Mg. |
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| ISSN: | 2075-4701 |