In this paper, the ice nucleation temperatures of 10 μL water droplets on a series of sol-gel coatings with different roughness and surface energies were obtained using a customized automatic measurement system. Classical nucleation theory was then employed to explain the different icing behaviour on the coatings. It was found that the wetting mode at low temperatures is strongly correlated with the icing behavior of the droplets on the surfaces. Ice-phobic coatings can lower the icing temperature of the droplet on the surface by up to 6.9 °C compared with non-icephobic ones. Using classical nucleation theory, our results support some recent observations that the dominant nucleation sites are along the substrate-water-vapour three-phase contact line rather than at the substrate-water interface.

Solute distribution and segregation in solidification will largely influence the characteristics of solidification microstructure and precipitation order of the second phase. In this paper, the solid-liquid interfaces of Mg-6Al alloy with different temperature were obtained by rapid quenching based on a special melting furnace and were analyzed using scanning electron microscopy, energy diffraction spectrum and Thermo-Calc calculation tool. It was found that the primary α-Mg phase grew through cystiform dendrite interface. The solute partition coefficient and dendrite segregation rate for Al in the solid phase of Mg-6Al alloy basically had little change with decrease of the temperature. The dendrite become fine, and the solute partition coefficient decreased, while dendrite segregation rate of Al in the dendrite boundaries increased, because of the addition of Zn to Mg-6Al alloys.