Metallic foam processing from the liquid state - The competition between solidification and drainage

A model is developed to describe the formation of metallic foams in which l iquid drainage acts to collapse the foam before it can freeze. Numerical so lution of the foam drainage equation, combined with the equations of heat c onduction, provides new insight into the competition between these two proc esses. It also stimulates and confirms a theoretical analysis which leads t o criteria for creating uniform samples of frozen metal foam. The analysis suggests new experiments to clarify the role of the various processes leadi ng to foam formation.