J. Ramirez, Arnoldo Badillo, Dan Ceynar, C. Beckermann, and A. Karma (Northeastern University)

The research focuses on the following issues:

• Selection of the dendrite tip operating state and the dendrite sidebranching behavior in the presence of melt convection for free growth into a supercooled melt of a pure substance: this research will primarily rely on our recently developed ability to perform phase-field simulations with convection in three dimensions; results will be compared to theories and experiments.
• Growth of multiple equiaxed dendrites inside a unit cell with/without flow: this research is aimed at improving models of solidifying mushy zones and understanding the thermal/solutal interactions between dendrites; it will again rely on the phase-field method, incorporating a model for multiple grains.
• Free growth of binary alloy dendrites in the presence of coupled heat and solute transport: issues to be addressed are the selection of the dendrite tip operating state, sidebranching behavior, effect of the large disparity in the thermal and solutal diffusion lengths, and influence of convection; the research will involve development of a phase-field model and performing benchmark experiments using the existing dendrite growth setup built under the EDSE/DASE projects at the University of Iowa.