An embodiment of the present invention provides a method for improving the tensile strength of foundry cores and molds. More particularly, an embodiment of the present invention provides an improved binder for foundry cores and molds that include a fluoride bearing acid in combination with an inorganic silicon compound. Alternately, the improved binder may include a fluoride bearing acid in combination with a boron compound. In a preferred embodiment, a modified part 1 binder component includes a combination of hydrofluoric acid and an inorganic silicon compound.
This invention relates to a polyurethane-forming no-bake foundry binder comprising a (a) polyether polyol component comprising (1) a polyether polyol, (2) hydrofluoric acid, and (3) an aminoalkoxysilane, (b) a polyisocyanate component, (c) a liquid tertiary amine catalyst component. Foundry mixes are prepared by mixing the binder system with a foundry aggregate by a no-bake process. The resulting foundry shapes are used to cast metal parts from ferrous and non-ferrous metals.
