Methods for preparing and applying coatings on metal-based substrates, and related compositions and articles
AssigneeGeneral Electric Company
InventorD Sangeeta
Life of this patent
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Abstract
A method for preparing an aluminum alloy-containing coating composition is described. A slurry containing a selected amount of aluminum is combined with at least one additional slurry containing a selected amount of a second metal which forms an alloy with aluminum. The resulting slurry mixture is applied to a metal substrate, and then heated to form a substantially devolatilized coating. The coating then receives a secondary heat treatment. Related compositions and articles are also described, as are processes for repairing a damaged or worn coating, utilizing the slurry.
Claims37
A method for preparing an aluminum alloy-containing coating composition, comprising the step of mixing a first slurry comprising a selected amount of aluminum with at least one additional slurry comprising a selected amount of a second metal which forms an alloy with aluminum, wherein the amount of aluminum and the amount of the second metal in the respective slurries are substantially proportional to the desired proportion of aluminum to the second metal for the coating composition.
The method of 6, wherein the atomic ratio of platinum to aluminum in the slurry mixture ranges from about 1:99 to about 80:20.
The method of 10, wherein the atomic ratio of nickel to aluminum in the slurry mixture ranges from about 5:95 to about 80:20.
A method for applying an aluminum alloy-containing coating to a metal-based substrate, comprising the following steps:
- (a) mixing a first slurry comprising a selected amount of aluminum with a second slurry comprising a selected amount of a second metal selected from the group consisting of a noble metal, nickel and mixtures thereof, which forms an alloy with aluminum, thereby forming a slurry mixture, wherein the amount of aluminum and the amount of the second metal in the respective slurries are substantially proportional to a desired proportion of aluminum to the second metal for the coating;
- (b) applying the slurry mixture to the metal-based substrate;
- (c) heating the applied slurry mixture to remove at least a portion of the volatile material contained therein, forming a substantially devolatilized coating;
- and
- (d) subjecting the substantially devolatilized coating to a secondary heat treatment.
A method for forming a platinum-aluminide coating on a superalloy substrate, comprising the following steps:
- (I) applying a volatile-containing slurry mixture to the substrate, wherein said mixture comprises a selected amount of aluminum and a selected amount of platinum, wherein the amounts of aluminum and platinum are substantially proportional to a desired proportion of aluminum to platinum for the coating;
- and then
- (II) heating the applied slurry mixture under conditions sufficient to remove substantially all of the volatile material contained therein, and to diffusion heat-treat the substantially devolatilized coating.
A method for repairing a damaged or worn coating formed from an alloy of aluminum with at least one additional metal, applied over a metal-based substrate, comprising the following steps:
- (i) removing the damaged or worn coating from a selected area on the substrate;
- and then
- (ii) applying additional coating material over the selected area, by
- (A) mixing a slurry comprising a selected amount of aluminum with a slurry comprising a selected amount of the additional metal, thereby forming a slurry mixture, wherein the amount of aluminum and the amount of the additional metal in the respective slurries are substantially proportional to a desired proportion of aluminum to the additional metal for the alloy;
- (B) applying the slurry mixture to the metal-based substrate;
- (C) heating the applied slurry mixture to remove substantially all of the volatile material contained therein, forming a substantially devolatilized coating;
- and
- (D) subjecting the substantially devolatilized coating to a secondary heat treatment sufficient to sinter, diffuse, or crystallize the substantially devolatilized coating.
A slurry composition comprising aluminum and platinum and, optionally, nickel.
An article, comprising:
- (i) a metal-based component of a turbine engine;
- and
- (ii) a volatile-containing slurry which comprises aluminum and at least one additional metal selected from the group consisting of a noble metal, nickel and mixtures thereof, which forms an alloy with aluminum, applied over the component of the turbine engine.
Dependencies are inferred from the claim text.