Life extension of chromium coatings and chromium alloys

Abstract

Substrates comprising a surface comprising chromium, said surface being adapted to exhibit reduced coefficient of friction and/or increased hardness.

We claim:  
     
         1 . A substrate comprising chromium and a gradient from an inside to an outside surface consisting essentially of: 
 substrate molecules/a mixture of said substrate molecules and substrate-X molecules comprising chromium-X/a surface comprising a sufficient quantity of said chromium-X molecules to produce a final coefficient of friction in an unlubricated condition against a steel counterface that is less than a virgin coefficient of friction of said surface in the absence of said gradient;    wherein X is selected from the group consisting of fluorine (F), oxygen (O), and sulfur (S).    
     
     
         2 . The substrate of  claim 1  wherein X is F.  
     
     
         3 . The substrate of  claim 1  wherein X is S.  
     
     
         4 . The substrate of  claim 1  wherein said gradient further comprises chromium carbide molecules.  
     
     
         5 . The substrate of  claim 2  wherein said gradient further comprises chromium carbide molecules.  
     
     
         6 . The substrate of  claim 3  wherein said gradient further comprises chromium carbide molecules.  
     
     
         7 . The substrate of  claim 1  comprising chromium-X molecules to a depth of 50 nm or more from the outer surface of said substrate.  
     
     
         8 . The substrate of  claim 1  comprising chromium-X molecules to a depth of 150 nm or more from the outer surface of said substrate.  
     
     
         9 . The substrate of  claim 1  comprising chromium-X molecules to a depth of 250 nm or more from the outer surface of said substrate.  
     
     
         10 . The substrate of  claim 1  having a final hardness of about 15 GPa or more.  
     
     
         11 . The substrate of  claim 1  having a final hardness of about 20 GPa or more.  
     
     
         12 . The substrate of  claim 1  having a final hardness of about 25 GPa or more.  
     
     
         13 . The substrate of  claim 1  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         14 . The substrate of  claim 1  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         15 . The substrate of  claim 1  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         16 . The substrate of  claim 10  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         17 . The substrate of  claim 10  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         18 . The substrate of  claim 10  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         19 . The substrate of  claim 11  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         20 . The substrate of  claim 11  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         21 . The substrate of  claim 11  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         22 . The substrate of  claim 12  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         23 . The substrate of  claim 12  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         24 . The substrate of  claim 12  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         25 . The substrate of  claim 1  wherein said substrate comprises a chromium content and said sufficient quantity comprises from about 10 atomic % to about 40 atomic % oxygen.  
     
     
         26 . The substrate of  claim 1  wherein said substrate comprises a chromium content and sufficient quantity comprises about 25 atomic % oxygen.  
     
     
         27 . The substrate of  claim 2  comprising chromium-fluorine molecules to a depth of 50 nm or more from the outer surface of said substrate.  
     
     
         28 . The substrate of  claim 2  comprising chromium-fluorine molecules to a depth of 150 nm or more from the outer surface of said substrate.  
     
     
         29 . The substrate of  claim 2  comprising chromium-fluorine molecules to a depth of 250 nm or more from the outer surface of said substrate.  
     
     
         30 . The substrate of  claim 2  having a final hardness of about 15 GPa or more.  
     
     
         31 . The substrate of  claim 2  having a final hardness of about 20 GPa or more.  
     
     
         32 . The substrate of  claim 2  having a final hardness of about 25 GPa or more.  
     
     
         33 . The substrate of  claim 2  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         34 . The substrate of  claim 2  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         35 . The substrate of  claim 2  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         36 . The substrate of  claim 2  wherein said substrate comprises a chromium content and said sufficient quantity comprises from about 10 atomic % to about 40 atomic % F.  
     
     
         37 . The substrate of  claim 2  wherein said substrate comprises a chromium content and said sufficient quantity comprises about 25 atomic % F.  
     
     
         38 . The substrate of  claim 3  comprising chromium-S molecules to a depth of 50 nm or more from the outer surface of said substrate.  
     
     
         39 . The substrate of  claim 3  comprising chromium-S molecules to a depth of 150 nm or more from the outer surface of said substrate.  
     
     
         40 . The substrate of  claim 3  comprising chromium-S molecules to a depth of 250 nm or more from the outer surface of said substrate.  
     
     
         41 . The substrate of  claim 3  having a final hardness of about 15 GPa or more.  
     
     
         42 . The substrate of  claim 3  having a final hardness of about 20 GPa or more.  
     
     
         43 . The substrate of  claim 3  having a final hardness of about 25 GPa or more.  
     
     
         44 . The substrate of  claim 3  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         45 . The substrate of  claim 3  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         46 . The substrate of  claim 3  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         47 . The substrate of  claim 41  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         48 . The substrate of  claim 41  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         49 . The substrate of  claim 41  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         50 . The substrate of  claim 42  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         51 . The substrate of  claim 42  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         52 . The substrate of  claim 42  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         53 . The substrate of  claim 43  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         54 . The substrate of  claim 43  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         55 . The substrate of  claim 43  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         56 . The substrate of  claim 3  wherein said substrate comprises a chromium content and said sufficient quantity comprises from about 10 atomic % to about 40 atomic % S.  
     
     
         57 . The substrate of  claim 3  wherein said substrate comprises a chromium content and said sufficient quantity comprises about 25 atomic % S.  
     
     
         58 . A substrate comprising chromium and a gradient from an inside to an outside surface consisting essentially of: 
 substrate molecules/a mixture of said substrate molecules and substrate-oxygen (O) molecules comprising chromium-O/a surface comprising a sufficient quantity of said chromium-O molecules to produce a final coefficient of friction in an unlubricated condition against a steel counterface that is less than a virgin coefficient of friction of said surface in the absence of said gradient.    
     
     
         59 . The substrate of  claim 58  wherein said gradient further comprises chromium carbide molecules.  
     
     
         60 . The substrate of  claim 58  comprising chromium-O molecules to a depth of 50 nm or more from the outer surface of said substrate.  
     
     
         61 . The substrate of  claim 58  comprising chromium-O molecules to a depth of 150 nm or more from the outer surface of said substrate.  
     
     
         62 . The substrate of  claim 58  comprising chromium-O molecules to a depth of 250 nm or more from the outer surface of said substrate.  
     
     
         63 . The substrate of  claim 59  comprising chromium-O molecules to a depth of 50 nm or more from the outer surface of said substrate.  
     
     
         64 . The substrate of  claim 59  comprising chromium-O molecules to a depth of 150 nm or more from the outer surface of said substrate.  
     
     
         65 . The substrate of  claim 59  comprising chromium-O molecules to a depth of 250 nm or more from the outer surface of said substrate.  
     
     
         66 . The substrate of  claim 58  having a final hardness of about 15 GPa or more.  
     
     
         67 . The substrate of  claim 59  having a final hardness of about 15 GPa or more.  
     
     
         68 . The substrate of  claim 65  having a final hardness of about 15 GPa or more.  
     
     
         69 . The substrate of  claim 58  having a final hardness of about 20 GPa or more.  
     
     
         70 . The substrate of  claim 59  having a final hardness of about 20 GPa or more.  
     
     
         71 . The substrate of  claim 65  having a final hardness of about 20 GPa or more.  
     
     
         72 . The substrate of  claim 58  having a final hardness of about 25 GPa or more.  
     
     
         73 . The substrate of  claim 59  having a final hardness of about 25 GPa or more.  
     
     
         74 . The substrate of  claim 65  having a final hardness of about 25 GPa or more.  
     
     
         75 . The substrate of  claim 58  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         76 . The substrate of  claim 58  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         77 . The substrate of  claim 58  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         78 . The substrate of  claim 59  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         79 . The substrate of  claim 59  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         80 . The substrate of  claim 59  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         81 . The substrate of  claim 65  wherein said final coefficient of friction is about 0.3 or less.  
     
     
         82 . The substrate of  claim 65  wherein said final coefficient of friction is about 0.2 or less.  
     
     
         83 . The substrate of  claim 65  wherein said final coefficient of friction is about 0.1 or less.  
     
     
         84 . The substrate of  claim 58  wherein said substrate comprises a chromium content and said sufficient quantity comprises from about 10 atomic % to about 40 atomic % oxygen.  
     
     
         85 . The substrate of  claim 58  wherein said substrate comprises a chromium content and sufficient quantity comprises about 25 atomic % oxygen.  
     
     
         86 . The substrate of  claim 58  wherein said gradient from inside to an outside surface consists essentially of chromium alloy molecules; a mixture comprising chromium alloy molecules and chromium-O molecules; a surface comprising a sufficient quantity of said chromium-O molecules to produce a final coefficient of friction in an unlubricated condition against a steel counterface that is less than a virgin coefficient of friction of said surface in the absence of said gradient.  
     
     
         87 . The chromium alloy substrate of  claim 86  wherein said gradient further comprises chromium carbide molecules.  
     
     
         88 . A substrate comprising a chromium coating comprising a gradient from inside to an outside surface consisting essentially of: 
 primarily chromium molecules/a mixture of chromium oxide molecules and chromium molecules/a surface comprising a sufficient quantity of said chromium oxide molecules to produce a final coefficient of friction in an unlubricated condition against a steel counterface that is less than a virgin coefficient of friction of said surface in the absence of said gradient.    
     
     
         89 . The substrate of  claim 88  wherein said gradient from inside to an outside surface consists essentially of chromium alloy molecules; a mixture comprising chromium alloy molecules and chromium oxide molecules; a surface comprising a sufficient quantity of said chromium oxide molecules to produce a final coefficient of friction in an unlubricated condition against a steel counterface that is less than a virgin coefficient of friction of said surface in the absence of said gradient.  
     
     
         90 . The substrate of  claim 89  wherein said gradient further comprises chromium carbide molecules.  
     
     
         91 . The substrate of  claim 89  wherein said gradient further comprises chromium alloy molecules.  
     
     
         92 . The substrate of  claim 89  comprising an automotive component.  
     
     
         93 . The substrate of  claim 89  comprising an aeronautical component.  
     
     
         94 . The substrate of  claim 89  comprising a journal bearing.  
     
     
         95 . The substrate of  claim 89  comprising a tool for injection molding of filled polymers.  
     
     
         96 . The substrate of  claim 89  wherein said tool is selected from the group consisting of a plated mold and a runner block.  
     
     
         97 . The substrate of  claim 91  comprising a medical implant.  
     
     
         98 . The medical implant of  claim 97  wherein said gradient further comprises chromium carbide molecules.  
     
     
         99 . The medical implant of  claim 97  comprising a total joint replacement.  
     
     
         100 . The medical implant of  claim 98  comprising a total joint replacement.