Acta Metallurgica Sinica (English Letters) ›› 2022, Vol. 35 ›› Issue (1): 124-132.DOI: 10.1007/s40195-021-01327-w

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Unveiling the Growth Mechanism of Faceted Primary Al2Cu with Complex Morphologies During Solidification

Zongye Ding1,2, Qiaodan Hu2(), Fan Yang3(), Liao Yu2, Tianxing Yang2, Naifang Zhang2, Wenquan Lu2, Jingwei Yang1, Jian Qiao1, Jianguo Li2   

  1. 1School of Mechatronic Engineering and Automation, Foshan University, Foshan, 528225, China
    2Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
    3School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
  • Received:2021-08-05 Revised:2021-08-25 Accepted:2021-08-30 Online:2022-01-10 Published:2021-10-08
  • Contact: Qiaodan Hu,Fan Yang
  • About author:Fan Yang, fanyang_0123@sjtu.edu.cn
    Qiaodan Hu, qdhu@sjtu.edu.cn;

Abstract:

The growth characteristic of primary faceted Al2Cu intermetallic compounds (IMCs) during solidification was observed directly by synchrotron radiography. The formation and transition mechanisms of Al2Cu IMCs with diverse morphologies were elucidated by first-principle calculations combined with electron backscatter diffraction analysis. The Al2Cu crystals preferred to grow along the [001] direction and were bounded by {110} planes with the lowest surface energy. The faceted Al2Cu rod-like clusters consisted of multiple crystals with complete rod, hollowness and partial sides, which was attributed to the increase in strain energy and solute redistribution during solidification. The faceted Al2Cu with branches was characteristic with the perpendicular relationship between the main branches and side steps and partial coalescence at the junction, which was ascribed to the continuous propagation and growth of newly formed crystals along the diagonal direction.

Key words: Solidification, Synchrotron radiography, Intermetallic compounds, Crystal growth, Morphology