A Full View of the Interfacial Behavior Between the Liquid Al and Solid Ni by Synchrotron Radiation

Synchrotron X-ray radiography was utilized to in situ study the Ni dissolution during holding and growth behavior of intermetallic compounds (IMCs) during solidification at the liquid Al/solid Ni interface, and synchrotron tomography was used to reconstruct the diversified Al₃Ni phases. The dissolution and IMC growth was quantitatively analyzed. During holding, the solid Ni dissolved heterogeneously into liquid Al, and the quantification of Ni concentration was obtained from intensity values. The layered Al₃Ni₂ formed at the interface during solidification, following by columnar and needle-like Al₃Ni. The growth of Al₃Ni₂ layer followed a parabolic law, being controlled by bulk diffusion mechanism. The peritectic and proeutectic Al₃Ni grew along the length obviously at the early stage and coarsened in the late stage. The proeutectic Al₃Ni phase had a stronger [001] orientation than peritectic Al₃Ni phase.