Fine-Grained metallic coatings having the coefficient of thermal expansion matched to the one of the substrate

Abstract

Fine-grained (average grain size 1 nm to 1,000 nm) metallic coatings optionally containing solid particulates dispersed therein are disclosed. The fine-grained metallic materials are significantly harder and stronger than conventional coatings of the same chemical composition due to Hall-Petch strengthening and have low linear coefficients of thermal expansion (CTEs). The invention provides means for matching the CTE of the fine-grained metallic coating to the one of the substrate by adjusting the composition of the alloy and/or by varying the chemistry and volume fraction of particulates embedded in the coating. The fine-grained metallic coatings are particularly suited for strong and lightweight articles, precision molds, sporting goods, automotive parts and components exposed to thermal cycling. The low CTEs and the ability to match the CTEs of the fine-grained metallic coatings with the CTEs of the substrate minimize dimensional changes during thermal cycling and prevent premature failure.

1 .- 19 . (canceled)  
     
     
         20 . A method for forming a coating on a substrate, said method comprising the steps of: 
 (a) providing a permanent substrate which at room temperature has a coefficient of thermal expansion in the range between −5.0×10 −6  K −1  and 25×10 −6  K −1 ;    (b) depositing a fine grained metallic coating on the permanent substrate by a deposition process selected from the group consisting of electroplating, physical vapor deposition, chemical vapor deposition, gas condensation, powder coating, cold spraying and kinetic metallization, wherein said fine grained metallic coating has an average grain size between 2 and 1,000 nm, a thickness between 25 microns and 5 cm and a coefficient of thermal expansion in the range between −5.0×10 −6  K −1  and 25×10 −6  K −1 ;    to produce a coated substrate wherein said fine grained metallic coating exhibits no delamination and the displacement of the fine grained coating relative to the underlying substrate is less than 2% after said coated substrate has been exposed to one temperature cycle consisting of exposure to liquid nitrogen for one minute followed by exposure to 90° C. hot water for one minute, or one temperature cycle according to ASTM B553-71 service condition 1, 2, 3 or 4.    
     
     
         21 . The method according to  claim 20  wherein said electroplating is selected from the group of DC and pulse electrodeposition.  
     
     
         22 . The method of  claim 20  wherein said fine-grained metallic coating is of a metallic material selected from the group consisting of: 
 (i) a pure metal selected from the group consisting of Al, Cu, Co, Ni, Fe, Mo, Pt, Ti and Zr,    (ii) an alloy containing at least two elements selected from the metals of (i);    (iii) an alloy containing at least two of the metals of (i) and, further containing at least one element selected from the group consisting of Ag, Au, B, C, Cr, Mo, Mn, P, S, Si, Pb, Pd, Rh, Ru, Sn, V, W and Zn;    (iv) any of (i), (ii) or (iii) also containing particulate additions in a volume fraction between 0 and 95%.    
     
     
         23 . The method of  claim 20 , wherein the fine-grained metallic coating contains particulate addition and said particulate addition is of one or more materials which is a metal selected from the group consisting of Ag, Al, Cu, In, Mg, Si, Sn, Pt, Ti, V, W, Zn; a metal oxide selected from the group consisting of Ag 2 O, Al 2 O 3 , SiO 2 , SnO 2 , TiO 2 , ZnO; a nitride of Al, B, or Si; a carbide of B, Cr, Bi, Si, or W; a carbon based material selected from the group consisting of a carbon nanotube, diamond, graphite, graphite fibers; ceramic, glass; and polymer material selected from the group consisting of PTFE, PVC, PE, PP, ABS, epoxy resin.  
     
     
         24 . The method according to  claim 22  where the fine-grained metallic coating is composed of 5%-95% by weight Fe alloyed with at least one element selected from the group consisting of Ni and Co and where the combined Ni/Co content ranges from 2.5% to 95% by weight.  
     
     
         25 . The method according to  claim 22  where the fine-grained metallic coating contains P.  
     
     
         26 . The method according to  claim 25  above wherein the fine-grained metallic coating comprises at least one element selected from the group consisting of Ni and Co.  
     
     
         27 . The method according to  claim 25  wherein the fine-grained metallic coating is dispersion strengthened by a heat treatment after it is deposited.  
     
     
         28 . The method according to  claim 25  wherein the fine-grained metallic coating contains diamond particulate addition.  
     
     
         29 . The method according to  claim 25  wherein depositing is by electroplating.  
     
     
         30 . The method according to  claim 20  where the permanent substrate is of a material selected from the group consisting of metals, metal alloys, glass, ceramics, filled polymeric materials, polymeric composites, and carbon based materials selected from the group consisting of graphite, graphite fibers and carbon nanotubes.  
     
     
         31 . The method according to  claim 30  where the permanent substrate comprises a fine-grained or coarse grained metal selected from the group consisting of Al, Cu, Co, Ni, Fe, Mo, Pt, Ti, W, and Zr.  
     
     
         32 . The method according to  claim 30  where the permanent substrate comprises a filled polymeric material with the filler selected from the group consisting of carbon, carbon fibers, graphite fibers, diamond, graphite and carbon nanotubes.  
     
     
         33 . The method according to  claim 20  where an intermediate conductive layer is applied to said substrate before said fine-grained metallic material that constitutes the fine-grained metallic coating is applied.  
     
     
         34 . The method according to  claim 33  where the intermediate conductive layer comprises a metallic layer constituted of Ag, Ni or Cu or a combination of any two or all of these, and where the intermediate conductive layer is applied by a process selected from the group consisting of electroless deposition, sputtering, thermal spraying, chemical vapor deposition, physical vapor deposition and by any two or more of these.  
     
     
         35 . The method according to  claim 33  where the intermediate conductive layer comprises polymeric material with conductive particulates therein.  
     
     
         36 . The method according to  claim 33  where the intermediate conductive layer is a conductive paint or a conductive epoxy.  
     
     
         37 . The method according to  claim 35  where the conductive particulates are composed of or contain Ag, Ni or Cu or graphite or other conductive carbon or a combination of two or more of them.  
     
     
         38 . The method according to  claim 20 , wherein said produced coated substrate is a component or part for automotive, aerospace, sporting equipment, manufacturing or industry application.  
     
     
         39 . The method according to  claim 20 , wherein the produced coated substrate comprises a component or part selected from the group consisting of a golf club face plate, a golf club head, a golf club shaft, a fishing pole, a hiking pole, a skiing pole, a walking stick, a lacrosse stick, a hockey stick, an arrow, a bicycle frame, a racquet, a baseball bat, a ski, a skate blade, a snowboard, an ammunition cartridge casing, armor, a mold, a grille guard, a running board, a wire, a cable or a tubular structure.  
     
     
         40 . A method according to  claim 38  where the component or part is selected from the group consisting of golf clubs, fishing rods, arrows, hockey sticks, baseball/softball bats, tennis racquets, lacrosse sticks, ski poles, walking sticks, skate blades, snowboards, bicycle frames and molds.  
     
     
         41 . The method according to  claim 20 , wherein the substrate of the produced coated substrate has a tubular structure and said fine-grained metallic coating extends over at least part of the inner or outer surface of said tubular structure.  
     
     
         42 . A method according to  claim 38  where the component or part is selected from the group consisting of a golf club shaft, an arrow shaft, a cartridge casing, a baseball/softball bat, a fishing rod, a ski pole, a hiking pole and a bicycle part.  
     
     
         43 . The method according to  claim 20  wherein said substrate comprises a material selected from the group consisting of glass fibers, graphite, graphite fibers, carbon, carbon fibers and carbon nanotubes.  
     
     
         44 . The method according to  claim 20 , where the fine-grained metallic coating has a modulus of resilience between 0.25 and 25 MPa.  
     
     
         45 . The method according to  claim 30 , wherein said substrate is wire or cable and said fine-grained coating is of a material selected from the group consisting of metal, metal alloy or metal matrix composite and represents between 5 and 95% of the total weight of said coated substrate.  
     
     
         46 . The method according to  claim 20  where the substrate comprises graphite/carbon fibers embedded in epoxy, and wherein the weight of the fine-grained metallic material is between 5 and 95% of the total weight of the article.  
     
     
         47 . The method according to  claim 20 , wherein said fine-grained metallic coating is of a metallic material selected from the group consisting of Ni, Co or Fe based alloy and the substrate comprises graphite/carbon fibers embedded in epoxy.  
     
     
         48 . An article according to  claim 45 , wherein said produced coated substrate is a golf club shaft, an arrow shaft, a cartridge casing, a baseball/softball bat, a fishing rod, a ski pole, a hiking pole, a mold, a mold component, a tooling part, or an automotive or bicycle part.