Metal foams with porosities greater than 90 pet were prepared by a novel po
wder metallurgy route using a polymeric vehicle. Coarse titanium powder and
fine carbonyl iron powder were tested. The powders were blended with each
component of a two-part polyol-isocyanate foaming system, and the resulting
suspensions were mixed and allowed to expand. Although the resulting polym
er-metal foam was closed cell, particles were not retained in the windows.
Upon pyrolysis to remove the resin, the windows opened and the final sinter
ed metal foam was reticulated. Such foams present very low sintered density
and are correspondingly weak after sintering but offer a fine reticulated
structure with cell diameters in the region of 100 to 200 mum. They may hav
e applications in the areas of catalysis, biomaterials, and composites.