MODELING OF PHASE-SEPARATION IN LIQUIDS WITH A MISCIBILITY GAP

An analytically tractable theory is developed and solutions are presen ted describing the simultaneous action of three processes occurring du ring the phase transformation of a single phase fluid into a dispersio n of partially or immiscible liquids. These processes are nucleation, diffusional growth and sedimentation due to the action of gravity. A g eneral partial differential equation describing the transformation is developed and solved. Some special cases like a constant or time depen dent nucleation rate are treated explicitly. They are compared with ex periments performed with immiscible aluminum-bismuth alloys. The agree ment between theoretical prediction and experimental results is satisf actory.