Method of eliminating shrinkage porosity defects in the formation of cast molten metal articles using polystyrene chill

摘要

A method of eliminating solidification shrinkage porosity defects in cast metal articles includes disposing an expanded polystyrene chill (36) within a preformed mold cavity (26) and thereafter introducing molten metal into the cavity (26) and vaporizing the chill member (36), whereby the heat of vaporization rapidly cools a localized region of the molten metal adjacent the chill member and accelerates solidification thereof enabling remote still-molten metal to feed solidification shrinkage in this region and prevent the formation of porosity defects that would otherwise result.