Acta Metallurgica Sinica (English Letters) ›› 2024, Vol. 37 ›› Issue (12): 2094-2105.DOI: 10.1007/s40195-024-01762-5

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Effect of Glass Tube Suction Casting on Solidification Process and Si Refinement of Hypereutectic Al-Si Alloy

Chengcheng Han1,2, Yuna Wu1,2(), Hao Huang1,2, Chen Chen1, Huan Liu1(), Jinghua Jiang1, Aibin Ma1, Jing Bai3, Hengcheng Liao3   

  1. 1College of Materials Science and Engineering, Hohai University, Changzhou 213200, China
    2Suqian Research Institute, Hohai University, Suqian 223800, China
    3School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
  • Received:2024-05-27 Revised:2024-07-15 Accepted:2024-07-18 Online:2024-12-10 Published:2024-09-06
  • Contact: Yuna Wu, wuyuna@hhu.edu.cn;Huan Liu, liuhuanseu@hhu.edu.cn

Abstract:

This study unpicks the influence of the glass tube suction casting (GTSC) with different inner diameters (8, 10, 12 and 14 mm) on the solidification process of the hypereutectic Al-Si alloy (A390) and dissects the underlying mechanisms of the Al-Si divorced eutectic and refinement degree of the primary silicon particles (PSPs). The results show that a smaller inner diameter of the glass tube is more favorable for achieving Al-Si divorced eutectic in GTSC A390 alloy. Conversely, a larger inner diameter is more conducive to the formation of the lamellar eutectic Si. The GTSC A390 alloy with an inner diameter of 10 mm achieves the smallest average equivalent diameter (approximately 7.4 μm) of the PSPs. Being the prior diffusion channels for solute atoms, the grain boundaries and twin growth grooves of PSPs attract solute atoms (Cu, Mg, etc.) to enrich. The enriched solute atoms occupy the diffusion destinations of some Si atoms, which limits the overall growth of PSPs. These findings provide new insights into developing a simple and effective manufacturing process to refine the primary and eutectic Si phases in hypereutectic Al-Si alloys.

Key words: Al-Si alloy, Solidification, Primary Si particles, Divorced eutectic, Refinement