Non-catalytic nucleation coating for undercooled Cu₅₀Ni₅₀ melt

A non-catalytic nucleation coating (B-F₃) was prepared by the high temperature curing process of the sol-gel glass film based on the viscous flow mechanism of the coating. X-ray diffraction technology was adopted to study the crystallization behavior of the coating as a function of treating temperature. It was evident that no crystallization phenomenon happened on the coating which kept stable after the heat treatment of 60 min at 1773 K. The purified melt of Cu₅₀Ni₅₀ was selected to evaluate the effectiveness of undercooling heredity of the coating in the undercooling experiments. The maximum undercooling of the melt solidified in the coated mold could reach 236 K. Based on the solidified microstructural evolution at different undercoolings, a single crystal of the alloy Cu₅₀Ni₅₀ was achieved with no aid of the selection process of the crystal in the mold with the B-F₃ coating by means of undercooling technology.