Process for making a composite aluminum article

Abstract

A process for making a composite aluminum article includes: treating an anodized, sealed aluminum substrate with a low friction material adherent to said substrate. The resulting substrate is then treated with an aqueous solution or suspension containing at least one salt having an anion, a cation, or both of a divalent metal or a trivalent metal. The process is particularly useful for producing hard anodized cookware, which exhibits improved acid and stain resistance.

1 . A process for making a composite aluminum article comprising: 
 (a) treating an anodized, sealed aluminum substrate with a low friction material adherent to said substrate thereby producing a low friction material-treated substrate; and    (b) treating said low friction material-treated substrate with an aqueous solution or suspension containing at least one salt having an anion, a cation, or both of a divalent metal or a trivalent metal;    thereby producing a composite aluminum article.    
   
   
       2 . The process of  claim 1 , wherein said salt solution or suspension substantially saturates said low friction material-treated substrate.  
   
   
       3 . The process of  claim 1 , wherein said salt is one or both of a nickel salt and a cobalt salt.  
   
   
       4 . The process of  claim 3 , wherein said salt is a nickel salt.  
   
   
       5 . The process of  claim 4 , wherein said nickel salt is nickel acetate.  
   
   
       6 . The process of  claim 1 , wherein said low friction material is a polymer material.  
   
   
       7 . The process of  claim 1 , wherein the treatment of said low friction material-treated substrate with an aqueous solution or suspension containing at least one salt having an anion, a cation, or both of a divalent metal or a trivalent metal is performed at a temperature of 170° F.-180° F.  
   
   
       8 . The process of  claim 7 , wherein the pH of said solution is between 5.7 and 6.0.  
   
   
       9 . The process of  claim 8 , wherein said treatment is conducted for 6 to 15 minutes.  
   
   
       10 . An article made using the process of clam 1.  
   
   
       11 . The article of  claim 10 , wherein said article is a piece of cookware.  
   
   
       12 . The piece of cookware of  claim 11 , wherein said piece of cookware is selected from the group consisting of kettles, dutch ovens, pots, pans, skillets, griddles and waffle irons.  
   
   
       13 . A process for making a composite aluminum article comprising: 
 (a) sealing an anodized aluminum substrate;    (b) treating said sealed, anodized aluminum substrate with a low friction material adherent to said sealed, anodized aluminum substrate, thereby producing a low friction material-treated substrate; and    (c) treating said low friction material-treated substrate with an aqueous solution or suspension containing at least one salt having an anion, a cation, or both of a divalent metal or a trivalent metal;    thereby producing a composite aluminum article.    
   
   
       14 . The process of  claim 13 , wherein sealing comprises immersion in an aqueous solution or suspension containing at least one salt having an anion, a cation, or both of a divalent metal or a trivalent metal, thereby producing a sealed, anodized aluminum substrate.  
   
   
       15 . The process of  claim 13 , wherein sealing comprises immersion in water heated to near boiling.  
   
   
       16 . The process of  claim 13 , wherein said salt solution or suspension substantially saturates said low friction material-treated substrate.  
   
   
       17 . The process of  claim 13 , wherein said salt is one or both a nickel salt and a cobalt salt.  
   
   
       18 . The process of  claim 17 , wherein said salt is a nickel salt.  
   
   
       19 . The process of  claim 18 , wherein said nickel salt is nickel acetate.  
   
   
       20 . The process of  claim 13 , wherein said low friction material is a polymer material.  
   
   
       21 . The process of  claim 13 , wherein the treatment of said low friction material-treated substrate with an aqueous solution or suspension containing at least one salt having an anion, a cation, or both of a divalent metal or a trivalent metal is performed at a temperature of 170° F.-180° F.  
   
   
       22 . The process of  claim 21 , wherein the pH of said solution is between 5.7 and 6.0.  
   
   
       23 . The process of  claim 22 , wherein said treatment is conducted for 6 to 15 minutes.  
   
   
       24 . An article made using the process of clam  13 .  
   
   
       25 . The article of  claim 24 , wherein said article is a piece of cookware.  
   
   
       26 . The piece of cookware of  claim 25 , wherein said piece of cookware is selected from the group consisting of kettles, dutch ovens, pots, pans, skillets, griddles and waffle irons.