Slurry formulations for formation of reactive element-doped aluminide coatings and methods of forming the same
AssigneePraxair S.T. Technology, Inc.
InventorsZhihong Tang, Kevin E Garing, James K Knapp, Albert Feuerstein, Thomas F Lewis, III
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Abstract
Novel slurry formulations and processes for forming improved protective coatings used in the hot section components of gas turbine engines are provided. The process includes a unique two-step deposition methodology whereby the required concentration of reactive element within an improved reactive element doped aluminide coating can be consistently produced in a reproducible manner.
Claims17
A reactive element (RE) enriched layer derived from a slurry formulation, said slurry formulation comprising:
- a RE donor powder comprising a RE component selected from the group consisting of hafnium (Hf), zirconium (Zr), yttrium (Y), lanthanum (La), cerium (Ce), and any combination thereof;
- a halide-containing activator powder selected from the group consisting of aluminum fluoride, ammonium fluoride, chromium fluoride, ammonium chloride, chromium chloride, hafnium chloride, hafnium fluoride, hafnium oxychloride, zirconium chloride, zirconium fluoride, zirconium oxychloride, lanthanum chloride, yttrium chloride and any combination thereof;
- an inert filler powder;
- and
- a binder solution, said binder solution comprising a binder material dissolved in a solvent;
- wherein said slurry formulation is characterized by an absence of a carrier gas.
A method for producing a reactive element (RE)-enriched layer onto a part, comprising the steps of:
- providing a RE donor slurry comprising a RE donor and a halide activator;
- applying said RE donor slurry onto the part;
- heating the RE donor slurry to generate a halide vapor;
- reacting the halide vapor with said RE component contained in the donor slurry to produce RE halide gases;
- transporting said RE halide gases onto the part surface in the absence of a carrier gas;
- depositing said RE onto the part;
- followed by
- diffusing said RE into the part;
- and then
- chemically bonding the RE-enriched layer onto the part;
- and
- removing the slurry residues from the RE-enriched layer.
A reactive-element (RE)-doped aluminide coating prepared by a process, comprising the steps of:
- providing a RE donor slurry comprising a RE donor and a halide activator;
- applying said RE donor slurry onto the part surface;
- heating the halide activator to generate a halide vapor;
- reacting the halide vapor with said RE component contained in the donor slurry to produce RE halide gases;
- transporting said RE halide gases with the part surface in the absence of a carrier gas;
- depositing said RE onto the part surface;
- followed by
- diffusing said RE into the part surface;
- and then
- forming the RE-enriched layer onto the part;
- removing the slurry residues from the RE-enriched layer;
- depositing an aluminum-based material onto the part surface so as not interfere with the deposition of said RE halide gases;
- diffusing an aluminum-based material into said RE-enriched layer;
- aluminizing said RE-enriched coating layer;
- and
- forming an RE-doped aluminide coating.
A reactive-element (RE)-doped platinum aluminide coating adapted for use as an improved bond coat for ceramic thermal barrier coatings, said bond coat prepared by a process, comprising the steps of:
- depositing a platinum group metal selected from the group consisting of platinum, palladium, Iridium, Rhodium and any combination thereof;
- providing a RE donor slurry comprising a RE donor and a halide activator;
- applying said RE donor slurry onto the part surface;
- heating the halide activator to generate a halide vapor;
- reacting the halide vapor with said RE component contained in the donor slurry to produce RE halide gases;
- transporting said RE halide gases with the part surface in the absence of a carrier gas;
- depositing said RE onto the part surface;
- followed by
- diffusing said RE into the part surface;
- and then
- forming the RE-enriched layer onto the part;
- removing the slurry residues from the RE-enriched layer;
- depositing an aluminum-based material onto the part surface so as to not interfere with the deposition of said RE halide gases;
- diffusing an aluminum-based material into said RE-enriched layer;
- aluminizing said RE-enriched coating layer;
- forming an RE-doped platinum aluminide coating;
- and
- applying a ceramic thermal barrier coating over said RE-doped platinum aluminide coating.
Dependencies are inferred from the claim text.