Coated article resistant to corrosion with nano-crystalline layer

Abstract

In some examples, an article including a substrate and a multi-layered coating on at least a portion of the substrate. The multi-layered coating including at least one nano-crystalline layer comprising a metal or a metal alloy and a corrosion resistant layer on the at least one nano-crystalline layer. The nano-crystalline layer defining an average grain size of less than 50 nanometers (nm) and the corrosion resistant layer including at least one of nickel metal, tin metal, zinc metal, cadmium metal, chromium metal, nickel-phosphorus alloy, nickel-sulfur alloy, nickel-boron alloy, nickel-cadmium alloy, nickel-zinc alloy, and tin-zinc alloy.

What is claimed is: 
     
         1 . An article comprising:
 a substrate; and   a multi-layered coating on at least a portion of the substrate, the multi-layered coating comprising:
 at least one nano-crystalline layer comprising a metal or a metal alloy, the nano-crystalline layer defining an average grain size of less than 50 nanometers (nm), and 
 a corrosion resistant layer on the at least one nano-crystalline layer, wherein the corrosion resistant layer comprises at least one of nickel metal, tin metal, zinc metal, cadmium metal, chromium metal, nickel-phosphorus alloy, nickel-sulfur alloy, nickel-boron alloy, nickel-cadmium alloy, nickel-zinc alloy, and tin-zinc alloy. 
   
     
     
         2 . The article of  claim 1 , wherein the corrosion resistant layer is configured to inhibit the discoloration of the multi-layered coating during a salt spray corrosion test at about 35° C. over about a 24 hour period. 
     
     
         3 . The article of  claim 1 , wherein the corrosion resistant layer comprises nickel metal or an alloy of nickel. 
     
     
         4 . The article of  claim 1 , wherein the substrate comprises a polymeric material. 
     
     
         5 . The article of  claim 4 , wherein the substrate further comprises reinforcement fibers. 
     
     
         6 . The article of  claim 4 , wherein the polymeric material comprises at least one of polyether ether ketone (PEEK), polyamide (PA), polyimide (PI), bis-maleimide (BMI), epoxy, phenolic polymers (e.g., polystyrene), polyesters, polyurethanes, silicone rubbers, and combinations thereof. 
     
     
         7 . The article of  claim 1 , wherein the at least one nano-crystalline layer comprises cobalt or cobalt alloy. 
     
     
         8 . The article of  claim 7 , wherein the at least one nano-crystalline layer comprises cobalt-nickel alloy. 
     
     
         9 . The article of  claim 1 , wherein the at least one nano-crystalline layer comprises a first nano-crystalline layer comprising a first metal or metal alloy and a second nano-crystalline layer comprising a cobalt or cobalt alloy, wherein the second nano-crystalline layer is in direct contact with the corrosion resistant layer. 
     
     
         10 . The article of  claim 1 , wherein the article comprises a component for a gas turbine engine selected from a group consisting of a cold section component, an engine inlet component, a particle separator, a support structure, a bracket, a blade, a vane, or an engine casing. 
     
     
         11 . The article of  claim 1 , wherein the corrosion resistant layer comprises nickel-phosphorus alloy. 
     
     
         12 . The article of  claim 1 , wherein the corrosion resistant layer comprises a coarse-grain metal or metal alloy. 
     
     
         13 . A method of forming an article comprising:
 depositing at least one nano-crystalline layer on a substrate, the at least one nano-crystalline layer comprising a metal or a metal alloy and defines an average grain size of less than 50 nanometers (nm); and   depositing a corrosion resistant layer on the at least one nano-crystalline layer, wherein the corrosion resistant layer comprises at least one of nickel metal, tin metal, zinc metal, cadmium metal, chromium metal, nickel-phosphorus alloy, nickel-sulfur alloy, nickel-boron alloy, nickel-cadmium alloy, nickel-zinc alloy, and tin-zinc alloy.   
     
     
         14 . The method of  claim 13 , wherein the corrosion resistant layer is configured to inhibit the discoloration of the multi-layered coating during a salt spray corrosion test at about 35° C. over about a 24 hour period. 
     
     
         15 . The method of  claim 13 , wherein the corrosion resistant layer comprises nickel metal or an alloy of nickel. 
     
     
         16 . The method of  claim 13 , wherein the nano-crystalline layer comprises cobalt or cobalt alloy. 
     
     
         17 . The method of  claim 13 , wherein depositing the corrosion resistant layer comprises depositing by electroless deposition a coarse-grain nickel-phosphorus alloy. 
     
     
         18 . The method of  claim 13 , further comprising depositing a base metal layer on the substrate, wherein the base metal layer is between the substrate and the at least one nano-crystalline layer. 
     
     
         19 . The method of  claim 13 , wherein the substrate comprises a polymer. 
     
     
         20 . An article comprising:
 a substrate; and   a multi-layered coating applied on at least a portion of the substrate, the multi-layered coating comprising:
 a first nano-crystalline layer comprising a metal or a metal alloy, the first nano-crystalline layer defining an average grain size of less than 50 nanometers (nm), and 
 a second nano-crystalline layer on the first nano-crystalline layer, the second nano-crystalline layer comprising cobalt or cobalt alloy, the second nano-crystalline layer defining an average grain size of less than 50 nm, and 
 a corrosion resistant layer deposited on the second nano-crystalline layer, wherein the corrosion resistant layer comprises a component selected from the list consisting of nickel metal, tin metal, zinc metal, cadmium metal, chromium metal, nickel-phosphorus alloy, nickel-sulfur alloy, nickel-boron alloy, nickel-cadmium alloy, nickel-zinc alloy, and tin-zinc alloy.