ANALYSIS OF MONOTECTIC GROWTH - INFINITE DIFFUSION IN THE L-2 PHASE

The Jackson-Hunt model of eutectic solidification is applied to monote ctic solidification in which a liquid (L-1) transforms into rods of a different liquid (L-2) in a solid matrix. Limiting cases of no diffusi on and infinite diffusion (complete mixing) in the L-2 phase are consi dered. An adaptive refinement and multigrid algorithm (MGGHAT) is used to obtain numerical solutions for the concentration field in the L-1 phase; this allows consideration of a general phase diagram. Density d ifferences between the three phases, which cause fluid flow, are treat ed approximately. Specific calculations are carried out for aluminum-i ndium alloys. Infinite diffusion in the L-2 phase has only a small eff ect on the relationship between interface undercooling and rod spacing .