Abstract: A method of making a ceramic core for use in a casting process comprises the steps of forming a core in a mould by hot injection of a thermoplastic paste consisting of a refractory ceramic composition and an organic fraction, eliminating the organic fraction from the core by heat treatment, heat treating the core to achieve the minimum consolidation necessary to enable the core to be handled, impregnating the porous structure of the core with a solution comprising a silica or alumina based elementary oxide colloid, and eliminating the liquid from the impregnated product.

Abstract: A method of making a complex ceramic core for use in a metal casting process of the lost wax type, the core having at least one recess which extends into the interior of the core and being intended for use in the manufacture of a hollow component having internal cavities and partitions, including successive and superimposed injections of at least two compounds, one of which is degradable without harming the other(s), in at least one mold to produce a solid body wherein the other(s) of the compounds forms said core and the degradable compound fills the recesses of the core. The first injection creates a blank from one or other of the compounds, and each successive injection forms a layer which covers, at least partly, the outer surface of the blank obtained after the preceding injection until the solid body is completed. The body is then treated to remove the degradable compound and thereby leave the desired complex core.

Abstract: A method of making a shell mould, particularly for a lost wax casting operation, includes the deposition of an adhesion agent on the pattern before the deposition of layers of ceramic material to build up the mould. The adhesion agent used is preferably a 3% solution of aminosilane in a solvent consisting of ethanol and ethyl acetate in amounts from 25% to 75% of the solvent. The method avoids the phenomenon of detachment at the pattern/ceramic interface.