Planar and cylindrical jet streaming of water and of molten Fe40Ni40B20 alloy

Abstract

The nature of liquid streaming instabilities is an important consideration in many processes. In chill-block melt spinning of glassy metallic alloys, for example, molten alloy is expelled from a pressurized crucible in order to form a jet which is impinged and chilled against a rapidly moving substrate surface, thereby continuously casting ribbon or tape. The geometry of wide glassy alloy ribbons made by using a melt ejection crucible with a slit-shaped orifice is partially controlled by the tendency for the planar melt jet to undergo capillary inversion. The current investigation describes experiments in which the inversion lengths of planar water and molten Fe40Ni40B20 alloy streams were studied. The results show agreement with values obtained by using a theoretical model based on an inviscid isothermal liquid. Also, measurement of cylindrical jet break-up length has been conducted for both water and for molten Fe40Ni40B20 alloy. Results in both instances show agreement with a theoretically derived expression applying to an inviscid isothermal liquid if an experimentally measured stream perturbation factor is determined for each liquid. Therefore, it is shown that modeling of both planar and cylindrical molten alloy jet behavior is possible by either theoretical calculation based on an inviscid isothermal liquid or by water streaming experiments if differences in liquid density, surface tension, and stream perturbation factor are considered.