Intergrowth mechanism and morphology prediction of faceted Al₃Ni formed during solidification by a spatial geometric model

Zongye Ding¹，Qiaodan Hu^1,2，Wenquan Lu¹，Fan Yang³，Yihan Zhou¹，Naifang Zhang¹，Sheng Cao⁴，Liao Yu¹，Jianguo Li¹

1. Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University2. State Key Laboratory of Advanced Special Steel, Shanghai University3. School of Mechanical Engineering, Shanghai Jiao Tong University4. School of Materials, University of Manchester

摘 要：The interplay and intergrowth characteristic of faceted intermetallic compounds（IMCs） during solidification was originally investigated through the rod-like Al3 Ni crystals in the liquid Al/solid Ni interconnection by using synchrotron radiography, and the diversified 3-D morphologies were reconstructed by synchrotron tomography. A spatial geometric model was established to effectively predict the diversified growth patterns of two spatial crystals. For the two overlapping Al3 Ni crystals, the impeded crystal growth was divided into three different stages, decided by the hindrance form the other crystal. Further, the groove formed on the crystal surface is directly related to the solute redistribution under the critical condition of boundary layer thickness larger than two crystals distance. The closer distance and smaller crystal size indicate the deeper and larger groove, and the morphology changes from hemispheroid to hemi-ellipsoid with the increased opposite and interacted faces.

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