The Use of a Transparent Aqueous Analogue to Demonstrate the Development of Segregation Channels during Alloy Solidification, Vertically Upwards

摘要

The consequences of thermo-solutal convection during alloy solidification are demonstrated in a compilation of video recordings of analogous behavior in the transparent system, NH4CI-H20. The visual illustration is in five parts concerned with (1) general procedure, (2) the start of plume convection, (3) plume characteristics and interactions, (4) channel/plume correlation and particulate transport, and (5) channel detail and propagation. Wherever possible, attention is drawn to parallel behavior in the aqueous and an organic system with that thought to take place in opaque metallic systems. Extrapolation between the convection in metallic, aqueous and organic systems is briefly discussed.