Wettability of zirconium-coated alumina by molten aluminum

The wetting behavior and interfacial phenomena of alumina, Zr-coated alumina, and bulk Zr with liquid aluminum at 700 °C was investigated by the sessile drop technique. Zirconium film deposited on alumina improved the wettability with aluminum and promoted the formation of the precursor film. With the increase of zirconium film thickness from 160 nm to 670 nm, the terminal contact angle decreases gradually and spreading rate increased and the precursor film became wider and thicker. Marangoni flow resulting from the surface tension gradient due to the interfacial interaction is a major factor resulting in the formation of the precursor film.