Effects of different Si content and Sr addition on microstructure characteristics and mechanical properties of cast Al-Si-Cu-Mg-Mn alloys
The Al-Si alloys are examined to explore the effects of different Si content on the grain size and solute content through the combination of experimental methods and phase-field simulation. Additionally, 0.08 wt% Sr element is added to the Al alloys with different Si content to evaluate the relevant...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-07-01
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| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425017119 |
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| Summary: | The Al-Si alloys are examined to explore the effects of different Si content on the grain size and solute content through the combination of experimental methods and phase-field simulation. Additionally, 0.08 wt% Sr element is added to the Al alloys with different Si content to evaluate the relevant modification effect on the microstructure characteristics and mechanical properties of Al-xSi-3Cu-0.6Mg-0.6Mn casting alloys. Phase-field simulations reveal that with the increase of Si content from 7 to 11 wt%, the coarse columnar grains of the microstructure of Al-Si alloy are gradually refined. When the Si content reaches 7 wt%, the degree of solute polarization is the largest, while as the Si content continues to be increased, the degree of solute polarization is decreased instead. TEM analysis revealed the presence of numerous spherical Al-Si-Sr nanoclusters, consisting of nano-sized atoms, at the intersections of the twinning in the modified eutectic Si phase. These nanoclusters formed parallelogram-like structures along the twinning boundaries in the Si crystals, which contributed to the isotropic growth of Si crystals. With the optimized Si content, different contents of Sr elements are added to investigate the mechanism of the effect on the Fe-rich phase β-AlFeSi in the alloy. It was found that the size of the needle-like Fe-rich phase was obviously refined by adding 200 ppm Sr, and the needle-like Fe-rich phase was basically invisible in the microstructure when the Sr content reached 800 ppm. Phase diagrams were calculated using Pandat thermodynamic simulation software to predict the formation of various precipitated phases and their interactions during solidification. |
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| ISSN: | 2238-7854 |