This SBIR Phase I project proposes to investigate an innovative new class of materials which can be applied to molten metal filtration. The proposed concept utilizes ceramic foams fabricated by chemical vapor deposition (CVD) as a porous medium for the filtration of liquid metal. These materials will offer dramatically increased strength, modulus, and corrosion resistance as well as an increase in the permeability of the foam filter. The development of this material will provide a high-strength, high surface area, high-permeability refractory filter for use in the aluminum and steel production industries. Reticulated refractory foam produced by CVD will provide the aluminum industry with a higher strength, finer pore size, greater void fraction filter medium than is currently available, and the non-oxide refractory materials desired by the steel industry. CVD technology makes possible the production of reticulated foams which require only 5-25% solid fraction with 100% open-pore faces, with pore sizes as fine as 600 pores per linear inch (ppi), compared to the current 30%-35% solid fraction of sintered/bonded particle foams which are limited to 65 ppi. Ultramet will fabricate refractory ceramic foams by CVD and conduct evaluations with regard to pore size and material choice. Information on the priming head, molten metal permeability, particle capture efficiency, and resistance to molten metal corrosion will also be generated.
