Controlled preparation of a novel GNP@MgO particles and its refinement mechanism in Mg-9Al alloy
The addition of effective nucleating particles in the melt to achieve grain refinement has become the most widely used method for the casting industries. In this study, a novel GNP@MgO particle with a nanocomposite structure was prepared by utilizing an in-situ reaction of the carbon source gas with...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
KeAi Communications Co., Ltd.
2025-04-01
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| Series: | Journal of Magnesium and Alloys |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2213956724000288 |
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| Summary: | The addition of effective nucleating particles in the melt to achieve grain refinement has become the most widely used method for the casting industries. In this study, a novel GNP@MgO particle with a nanocomposite structure was prepared by utilizing an in-situ reaction of the carbon source gas with Mg melt. The results showed that the particles can significantly reduce the average grain size of Mg-9Al alloy from 130.4 µm to 13.1 µm, and achieve an ultra-high grain refinement efficiency of 90%. The refinement mechanisms are that the Al4C3 phase can act as a heterogeneous nucleation site for α-Mg grains due to the orientation relationship as (001)Al4C3//(002)Mg. Meanwhile, the particle distribution model shows that the velocity of MgO particles is much higher than the growth rate of α-Mg grains. Therefore, it is pushed to the vicinity of grain boundaries during solidification, effectively limiting the growth of α-Mg grains. The remarkable grain refinement effect was achieved through the synergistic modulation of Al4C3 and MgO particles. This work may provide new insight into designing high efficiency grain refiners for Mg-Al alloys. |
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| ISSN: | 2213-9567 |