A powder binder product for use in making a slurry for investment casting molds comprising Nano-sized powders; and an organic polymer powder, wherein it does not require aqueous colloidal silica to produce slurries used to build investment casting molds. The Nano-sized powders comprise fumed alumina, boehmite, fumed silica, or fumed titanium oxide or combinations thereof. The coarse refractory powder, combined with the powder binder for mold manufacture, comprises milled zircon, tabular alumina or fused alumina, fused silica, alumino-silicate, zirconia, and yttria or combinations thereof. The organic polymer in a powder binder comprises a cellulose-based material. A powder investment casting binder, that once fired, consists of up to 96 weight percent aluminum oxide.

A powder binder product for use in making a slurry for investment casting molds comprising Nano-sized powders; and an organic polymer powder, wherein it does not require aqueous colloidal silica to produce slurries used to build investment casting molds. The Nano-sized powders comprise fumed alumina, boehmite, fumed silica, or fumed titanium oxide or combinations thereof. The coarse refractory powder, combined with the powder binder for mold manufacture, comprises milled zircon, tabular alumina or fused alumina, fused silica, alumino-silicate, zirconia, and yttria or combinations thereof. The organic polymer in a powder binder comprises a cellulose-based material. A powder investment casting binder, that once fired, consists of up to 96 weight percent aluminum oxide.

The present disclosure relates slip techniques for lost casting cores. The teachings thereof may be embodied in methods for producing a slip for use in casting, e.g., for production of complex metal blades in gas turbines. Some embodiments may include methods for producing a slip comprising: mixing at least one inorganic constituent with at least one first binder; and forming a slip with the mixture. The first binder may include a mixture of at least one epoxy resin and at least one sterically hindered amine as hardener.