Time-Dependent Behavior of Dendrites Under Diffusion-Controlled Conditions

Dendrites interact with hydrodynamic flows during solidification. In the presence of gravity, thermal and solutal buoyancy forces induce convective motion in the melt. The basic theories of dendritic growth, however, are best tested under diffusion-controlled conditions, where, ideally, gravitational acceleration and convection are absent, or at least drastically reduced. Microgravity experiments of the Isothermal Dendritic Growth Experiment (IDGE) were designed to measure convection-free dendritic growth. IDGE experiments to accomplish this were flown on United States Microgravity Payload Missions: USMP-2 (March 1994), USMP-3 (March 1996), and USMP-4 (December 1997).