US Patent 7360577 Process for lost-foam casting with chill

Process for the Lost-foam casting of aluminum or magnesium including spacing the cooling face of a chill from a selected surface of a pyrolizable polymeric foam pattern so as to provide at least a 0.5 mm gap therebetween, and filling the gap with Al or Mg melt so as to displace any pyrolysis products therein away from the cooling face, and otherwise prevent such products from becoming trapped by the melt against the cooling face of the chill.