US 7,610,945 B2 · Rare earth-based core constructions for casting refractory metal composites, and related processes

Abstract

A method of fabricating a core for a ceramic shell mold is disclosed. A porous core body is formed from at least about 50% by weight of at least one rare earth metal oxide. The core body is heated under heating conditions sufficient to provide the core with a density of about 35% to about 80% of its theoretical density. The core body is then infiltrated with a liquid colloid or solution of at least one metal oxide compound, e.g., rare earth metal oxides; silica, aluminum oxide, transition metal oxides, and combinations thereof. The infiltrated core body is then heated to sinter the particles without substantially changing the dimensions of the core body. Mold-core assemblies which include such a core body are also described. A description of processes for casting a turbine component, using the core, is also set forth herein.

Claims35

Dependent claims

A method of fabricating a core for a mold, comprising the following steps:

(a) forming a porous core body according to selected dimensions from a composition comprising a binder and at least about 50% by weight of at least one rare earth metal oxide, based on the total weight of the core body;
(b) heating the core body under heating conditions sufficient to remove a substantial portion of the binder and provide the core with a density of about 35% to about 80% of its theoretical density;
(c) infiltrating the core body with a liquid colloid or solution which comprises particles of at least one metal oxide compound or precursor thereof, selected from the group consisting of rare earth metal oxides;
silica, alumina, transition metal oxides, and combinations thereof;
and then
(d) heat-treating the particle-infiltrated core body under heating conditions sufficient to sinter the particles without substantially changing the dimensions of the core body.

3 more elements

Dependencies are inferred from the claim text.

Rare earth-based core constructions for casting refractory metal composites, and related processes

Life of this patent

Rare earth-based core constructions for casting refractory metal composites, and related processes

Life of this patent

Abstract

Claims35