Expansive coatings for anchoring to composite substrates

Abstract

A method of forming a coated composite article comprises treating a surface of a composite article to form a treated composite article having a plurality of voids in the surface, applying an expansive interface coating to the surface and plurality of voids of the treated composite article to form an intermediate composite article, the expansive interface coating comprising an expansive alloy, and applying a metallic coating to the intermediate composite article using one of electroless plating, electrolytic plating, and thermal spraying. Each void of at least a subset of the plurality of voids comprises an opening at the surface that is narrower than an inward dimension of the respective void.

1 . A method of forming a coated composite article, the method comprising:
 treating a surface of a composite article to form a treated composite article having a plurality of voids in the surface;   applying an expansive interface coating to the surface and plurality of voids of the treated composite article to form an intermediate composite article, the expansive interface coating comprising an expansive alloy; and   applying a metallic coating to the intermediate composite article using one of electroless plating, electrolytic plating, and thermal spraying;   wherein each void of at least a subset of the plurality of voids comprises an opening at the surface that is narrower than an inward dimension of the respective void.   
     
     
         2 . The method of  claim 1 , wherein the step of treating the surface comprises at least one of a chemical etching process and a mechanical etching process. 
     
     
         3 . The method of  claim 1 , wherein the step of applying the expansive interface coating comprises one of:
 soldering using a wire of the expansive alloy;   pouring the expansive alloy in a molten form;   cold spraying the expansive alloy as a powder; and   thermal spraying the expansive alloy as a powder.   
     
     
         4 . The method of  claim 3 , wherein a temperature of the expansive alloy in the molten form is less than a glass transition temperature of the composite article. 
     
     
         5 . The method of  claim 3 , wherein the step of applying the expansive interface coating further comprises: allowing the expansive interface coating to cool such that it expands and exerts a force against walls of each of the plurality of voids. 
     
     
         6 . The method of  claim 1 , wherein the expansive alloy comprises SAC305 or a bismuth alloy. 
     
     
         7 . The method of  claim 1 , wherein the metallic coating comprises one or a combination of cobalt, cobalt-phosphorous, copper, nickel, nickel-phosphorous, nickel-tungsten, tungsten carbide-cobalt, or tungsten carbide-cobalt chromium. 
     
     
         8 . The method of  claim 1 , wherein the composite article is formed from a polymer-based material. 
     
     
         9 . A treated composite article comprising:
 an outer surface; and   a plurality of voids formed in the outer surface;   wherein each void of at least a subset of the plurality of voids comprises an opening at the outer surface that is narrower than an inward dimension of the respective void.   
     
     
         10 . The treated composite article of  claim 9 , wherein each void of at least the subset of the plurality of voids further comprises at least one straight wall normal to or at an angle relative to the outer surface. 
     
     
         11 . The treated composite article of  claim 10 , wherein each void of at least the subset of the plurality of voids has a columnar geometry. 
     
     
         12 . The treated composite article of  claim 9 , wherein each void of at least the subset of the plurality of voids further comprises at least one curved wall. 
     
     
         13 . The treated composite article of  claim 12 , each void of at least the subset of the plurality of voids has a different geometry than a remainder of the plurality of voids. 
     
     
         14 . The treated composite article of  claim 9 , wherein the composite is a polymer-based material. 
     
     
         15 . The treated composite article of  claim 9 , wherein the composite is a ceramic or glass material. 
     
     
         16 . An intermediate composite article comprising:
 the treated composite article of  claim 9 ; and   an expansive interface coating applied to the outer surface and the plurality of voids, the expansive interface coating comprising an expansive alloy.   
     
     
         17 . The intermediate composite article of  claim 16 , wherein the expansive interface coating exerts force on at least one wall of each of the plurality of voids. 
     
     
         18 . The intermediate composite article of  claim 17 , wherein the expansive alloy comprises SAC305 or a bismuth alloy. 
     
     
         19 . A coated composite article comprising:
 the intermediate composite article of  claim 16 ; and   a metallic coating applied to the expansive interface coating.   
     
     
         20 . The coated composite article of  claim 19 , wherein the metallic coating comprises: cobalt, cobalt-phosphorous, copper, nickel, nickel-phosphorous, nickel-tungsten, tungsten carbide-cobalt, or tungsten carbide-cobalt chromium.