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US 9,957,629 B2Granted
Electroplated coatings
AssigneePraxair S.T. Technology, Inc.
InventorsJohn Foster, Zhihong Tang, Kevin Garing, Bradley J. Burton, Thomas F. Lewis, III
Life of this patent
Estimating the term…
Abstract
A modified electroplated nickel-based metallic alloy coating and method of forming the same is provided. The electroplated coatings exhibit unique microstructure and composition which improves performance over conventional metallic materials. The coatings have significantly higher strength at elevated service temperatures.
Claims19
An electroplated coating comprising:
- a nickel-based metallic electroplated composition comprising about 5-15 wt % cobalt, about 5-10 wt % chromium, about 5- 10 wt % aluminum, 0 to about 6 wt % molybdenum, 0 to about 6 wt % tungsten, 0 to about 6 wt % tantalum, 0 to about 6 wt % rhenium, 0 to about 2 wt % titanium, 0 to about 1 wt % zirconium, 0 to about 1 wt % hafnium, 0 to about 1 wt % yttrium, 0 to about 1 wt % silicon, 0 to about 0.2 wt % carbon, 0 to about 0.03 wt % boron and a remainder of nickel;
- said composition characterized by a multi-phase microstructure defined at least in part by a gamma nickel solid solution phase (γ-Ni phase) and a gamma prime phase of nickel aluminide (γ′-Ni3Al phase) distributed within said γ-Ni phase;
- said γ′-Ni3Al phase including a bimodal microstructure comprising a primary γ′-Ni3Al phase and a secondary γ′-Ni3Al phase;
- said secondary γ′-Ni3Al phase having a particle size smaller than that of the primary γ′-Ni3Al phase;
- said γ′-Ni3Al phase optionally including a uniform distribution within said γ-Ni phase;
- wherein said γ′-Ni3Al phase is contained in an amount that is at least about 40 vol % but no greater than about 90 vol % to thereby produce an ultimate tensile strength at service temperatures that is greater in comparison to a coating having a MCrAlY composition.
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A method of forming an electroplated coating comprising:
- providing a superalloy substrate;
- providing a plating solution with a precursor alloy powder wherein said precursor alloy powder comprises CoCrAlX or NiCoCrAlX, where X is one or more of Re, Ta, Mo, W, Hf, Y, Si, Zr, C, B or any combination thereof;
- electroplating nickel and said precursor alloy powder onto the substrate to form a green coating having a composition comprising about 5-15 wt % cobalt, about 5-10 wt % chromium, about 5-10 wt % aluminum, 0 to about 6 wt % molybdenum, 0 to about 6 wt % tungsten, 0 to about 6 wt % tantalum, 0 to about 6 wt % rhenium, 0 to about 2 wt % titanium, 0 to about 1 wt % zirconium, 0 to about 1 wt % hafnium, 0 to about 1 wt % yttrium, 0 to about 1 wt % silicon, 0 to about 0.2 wt % carbon, 0 to about 0.03 wt % boron and a remainder of nickel;
- performing a first heat treatment of said green coating at a temperature ranging from about 2000° F. to 2400° F. for a duration of about 2 to about 6 hours;
- diffusing the CoCrAlX or NiCoCrAlX powder composition into a nickel plating matrix to produce an intermediate coating;
- performing a second heat treatment of said composition at a temperature ranging from about 1400° F. to about 1950° F. for a duration of about 6 to about 48 hours;
- and
- precipitating a gamma-prime nickel aluminide phase (γ′-Ni3Al phase) to produce the electroplated coating.
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Dependencies are inferred from the claim text.