Polymeric organic carbonate materials useful as fillers for investment casting waxes

Abstract

Wax compositions that are useful, amongst other things, for forming investment casting patterns are described. One embodiment of the wax composition comprises: (a) pattern wax; and (b) from about 1% to about 85% by weight of a polymeric organic carbonate filler material. Examples of particular polymeric organic carbonate filler materials include, without limitation, polyethylene carbonate, polypropylene carbonate, poly(cyclohexane carbonate), poly(cyclohexane propylene carbonate), and mixtures thereof. Crosslinking the organic portion of the polymeric organic carbonate filler material can substantially reduce its thermal expansion. The wax compositions generally include other materials commonly used to form wax compositions. Such materials include waxes and resinous materials, conventional fillers, ultra-violet curable monomers, plasticizers, lubricants, and mixtures thereof. Conventional fillers, including urea, can be copolymerized with the polymeric organic carbonate filler material to reduce the dissolution and/or agglomeration of the filler. Wax patterns useful for forming investment casting molds are then made from such compositions using conventional techniques, such as injection molding. The patterns are serially immersed in slurries comprising refractory materials to form casting molds. Metal and metal alloy articles are then cast using such molds.