Advanced electrodeposited cobalt coatings

Abstract

Free standing articles or articles at least partially coated with substantially porosity free, fine-grained and/or amorphous Co-bearing metallic materials optionally containing solid particulates dispersed therein, are disclosed. The electrodeposited metallic layers and/or patches comprising Co provide, enhance or restore strength, wear and/or lubricity of substrates without reducing the fatigue performance compared to either uncoated or equivalent thickness Cr coated substrate. The fine-grained and/or amorphous metallic coatings comprising Co are particularly suited for articles exposed to thermal cycling, fatigue and other stresses and/or in applications requiring anti-microbial and hydrophobic properties.

What is claimed is: 
     
         1 . An article comprising:
 (i) a substrate material comprising at least one material selected from the group consisting of Fe, Al, Co, Cu, Cr, Mg, Ni, Sn, Ti, W, Zn, carbon, graphite, and graphite composites;   (ii) an electrodeposited substance forming a metallic layer and/or patch on said metallic substrate material or on an intermediate structure thereon, said metallic layer or patch comprising a minimum Co content of 75% per weight and having an as deposited microstructure which is fine-grained with an average grain size between 2 and 1,000 nm and/or amorphous, wherein said metallic layer or patch has a thickness between 6.4 microns and 254 microns, exhibits a tensile or compressive internal stress in the range of between 2.5 and 30 ksi, an as deposited Vicker's hardness between 100 VHN and 2,000 VHN, a ductility in the range of 0.1 to 35%, and a minimum porosity of 0.01%;   (iii) wherein said article is with or without at least one intermediate structure between said substrate material and the electrodeposited metallic layer and/or patch comprising Co;   wherein said article exhibits a fatigue life cycle number equivalent to or exceeding a fatigue life cycle number equivalent of one of either an uncoated substrate material or equivalent thickness engineering hard Cr coated substrate material having a hardness between 600 and 1,000 VHN, when tested at an applied stress of between ⅓ and ⅔ of the yield strength of said uncoated substrate material, wherein the equivalent thickness engineering hard chromium coated substrate material has the same thickness as the electrodeposited substance on said metallic substrate material or on the intermediate structure; and wherein said fatigue life cycle number is an axial fatigue cycle number or a rotating beam fatigue cycle number.   
     
     
         2 . The article according to  claim 1 , wherein said electrodeposited substance is selected from the group consisting of:
 (i) Co metal with unavoidable impurities;   (ii) alloys of Co with one or more metals selected from the group consisting of Ag, Al, Au, Cr, Cu, Fe, Ni, Mo, Pd, Pt, Rh, Ru, Sn, Ti, W, Zn and Zr;   (iii) Co metal as defined in (i) or Co alloys as defined in (ii) further containing at least one element selected from the group consisting of B, C, H, O, P and S; and   (iv) any of (ii) or (iii) where said electrodeposited substance comprising Co also contains particulate additions in a volume fraction between 2.5 and 50%.   
     
     
         3 . The article according to  claim 2 , wherein the electrodeposited substance comprises at least one particulate addition, wherein said particulate addition is at least one material selected from the group consisting of a metal, a metal oxide, and a carbon containing material. 
     
     
         4 . The article according to  claim 1 , wherein said article contains an intermediate structure between said electrodeposited metallic layer and/or patch comprising Co and said substrate, and wherein said intermediate structure is electrically conductive. 
     
     
         5 . The article according to  claim 4 , wherein the intermediate electrically conductive structure comprises at least one element selected from the group consisting of Ag, Co, Ni, Cu, and C. 
     
     
         6 . The article according to  claim 1 , wherein said article exhibits no delamination after said article has been exposed to at least one temperature cycle according to ASTM B553-71 service condition 1, 2, 3 or 4. 
     
     
         7 . The article according to  claim 1 , wherein said article has a tubular structure and said electrodeposited metallic layer and/or patch comprising Co extends over at least part of the inner or outer surface of said tubular structure. 
     
     
         8 . The article according to  claim 1 , wherein said electrodeposited substance contains P in the range of 1 to 25% per weight, W in the range of about 0 to 25% per weight and B in the range of between 0 and 5% per weight. 
     
     
         9 . The article according to  claim 1 , wherein said substrate material is metallic substance selected from the group consisting of Fe alloys, Ni alloys, Cu alloys, and Al alloys. 
     
     
         10 . The article of  claim 9 , wherein at least one of said metallic substrate material or said article is exposed to at least one heat treatment and/or cold deformation. 
     
     
         11 . The electrodeposited substance according to  claim 3 , wherein said at least one particulate addition is a carbon containing material selected from the group consisting of carbon nanotubes, diamond, graphite, and graphite fibers, metal carbides and polymer materials. 
     
     
         12 . The electrodeposited substance according to  claim 3 , wherein said at least one particulate addition is a carbide selected from the group consisting of B, Cr, Bi, Si, and W. 
     
     
         13 . The article according to  claim 1 , wherein said electrodeposited substance comprises between 1 and 25% of P. 
     
     
         14 . The electrodeposited substance of  claim 13  containing between 2.5 and 50% per volume of particulate addition, wherein said particulate addition comprises carbon. 
     
     
         15 . The electrodeposited substance of  claim 14  wherein said particulate addition is at least one material comprising carbon selected from the group consisting of carbon nanotubes, diamond, graphite, graphite fibers and a carbide of B, Cr, Bi, Si, and W. 
     
     
         16 . The article according to  claim 13 , wherein said electrodeposited substance as deposited comprises an amorphous microstructure. 
     
     
         17 . The article according to  claim 13 , wherein said electrodeposited substance as deposited comprises a mixed amorphous and crystalline microstructure. 
     
     
         18 . The electrodeposited substance of  claim 17  containing between 2.5 and 50% per volume of particulate addition. 
     
     
         19 . The article according to  claim 1 , wherein said electrodeposited substance consists of multi-layered laminates. 
     
     
         20 . The article according to  claim 19 , wherein said multi-layered laminates have a sublayer thickness in the range from 1.5 nm to 1,000 microns.