Forming aluminide coating using metal alloy gravel

Abstract

Methods are provided for coating a component. In one such method, the component is disposed with metal alloy gravel comprising aluminum. An aluminide coating is then formed on the component, where the aluminum from the metal alloy gravel diffuses into the component to form the aluminide coating.

What is claimed is: 
     
         1 . A method for coating a component, comprising:
 disposing the component with metal alloy gravel comprising aluminum; and   forming an aluminide coating on the component, wherein the aluminum from the metal alloy gravel diffuses into the component to form the aluminide coating.   
     
     
         2 . The method of  claim 1 , wherein the metal alloy gravel has an average particle size of at least about 0.125 inches. 
     
     
         3 . The method of  claim 1 , wherein the metal alloy gravel further comprises chrome aluminum. 
     
     
         4 . The method of  claim 1 , wherein the metal alloy gravel further comprises cobalt aluminum. 
     
     
         5 . The method of  claim 1 , further comprising heating the metal alloy gravel adjacent the component to a temperature between about 1200 degrees Fahrenheit and about 1750 degrees Fahrenheit. 
     
     
         6 . The method of  claim 1 , further comprising heating the metal alloy gravel adjacent the component to a temperature between about 1550 degrees Fahrenheit and about 1750 degrees Fahrenheit. 
     
     
         7 . The method of  claim 1 , wherein activator material is disposed with the metal alloy gravel. 
     
     
         8 . The method of  claim 7 , where the activator material comprises halide material. 
     
     
         9 . The method of  claim 1 , further comprising heat treating the aluminide coating to provide a heat treated diffusion coating. 
     
     
         10 . The method of  claim 9 , wherein the heat treating comprises heating the aluminide coating to a temperature between about 1700 degrees Fahrenheit and about 2100 degrees Fahrenheit. 
     
     
         11 . The method of  claim 9 , wherein the aluminide coating is a green state coating, and the heat treated diffusion coating is a three-zone aluminide coating. 
     
     
         12 . The method of  claim 1 , wherein the component is laid on top of the metal alloy gravel. 
     
     
         13 . The method of  claim 1 , wherein the component is partially submersed in the metal alloy gravel. 
     
     
         14 . The method of  claim 1 , wherein the component is completely submersed in the metal alloy gravel. 
     
     
         15 . The method of  claim 1 , further comprising masking a portion of the component such that the masked portion of the component is not coated with the aluminide coating. 
     
     
         16 . The method of  claim 1 , wherein the component comprises a nickel alloy. 
     
     
         17 . The method of  claim 1 , wherein the component is configured as a part of a gas turbine engine. 
     
     
         18 . The method of  claim 17 , wherein the component is an airfoil. 
     
     
         19 . A method for coating a component of a gas turbine engine, comprising:
 providing a bed of material, the bed of material comprising metal alloy material and activator material, and the metal alloy material comprising cobalt and aluminum, wherein the metal alloy material has an average particle size of at least about 0.125 inches;   disposing the component with the bed of material;   heating the bed of material and the component to form an aluminide coating on the component, wherein the component is heated to a temperature between about 1200 degrees Fahrenheit and about 1750 degrees Fahrenheit, and wherein the aluminum from the metal alloy material diffuses into the component to form the aluminide coating.   
     
     
         20 . A method for coating a component of a gas turbine engine, comprising:
 providing a bed of material, the bed of material comprising metal alloy material and activator material, and the metal alloy material comprising chrome and aluminum, wherein the metal alloy material has an average particle size of at least about 0.125 inches;   disposing the component with the bed of material;   heating the bed of material and the component to form an aluminide coating on the component, wherein the component is heated to a temperature between about 1200 degrees Fahrenheit and about 1750 degrees Fahrenheit, and wherein the aluminum from the metal alloy material diffuses into the component to form the aluminide coating.