Nucleation interface of Al-Sb alloys on single crystal Al₂O₃ substrate

Lattice structure information of heterogeneous nucleation at nucleation interface was present. The crystal orientation, and interfacial structure characteristic of liquid Al alloys nucleated on the basal surface (0001) Al₂O₃ single crystal substrate were identified by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) analysis. The preferred crystal orientations of pure Al and Al-1%Sb (mass fraction) alloy adjacent to the nucleation interface were examined as (200) and (220) planes of Al, respectively, and two corresponding orientation relationships were obtained. An improved nucleation efficiency and refined grains were attributed to both the reduced interplanar spacing of preferred orientation and the decrease of lattice misfit from 16.4% to 7.0% in Al-1%Sb/Al₂O₃ nucleation group.