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

Abstract The interplay and intergrowth characteristic of faceted intermetallic compounds (IMCs) during solidification was originally investigated through the rod-like Al3Ni 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 Al3Ni 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.