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.

Abstract: A metal or metal alloy article is cast using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article. The metal or metal alloy article is then analyzed for inclusions by N-ray analysis.

Abstract: Methods and compositions for forming shells for investment casting and methods for casting metal articles using the shells are described. One embodiment of the method comprises serially immersing a pattern in at least one, and perhaps several different slurries, each of which slurries comprises refractory material and from about 0 to about 30 volume percent inorganic binder. This forms a facecoat and plural refractory backup layers about the pattern, the facecoat and at least one backup layer defining a shell. The facecoat and/or the shell is then infiltrated with a binder. Infiltrating the shell with a binder is a key feature of the present invention. Infiltration refers to any process whereby a binder can be introduced into the facecoat and/or the subsequent layers built up about the shell.