Preform and method of repairing nickel-base superalloys and components repaired thereby
First Claim
1. A sintered preform consisting essentially of a sintered mixture of powders comprising a cobalt-base braze alloy and a cobalt-base wear-resistant alloy, the cobalt-base braze alloy constituting about 10 to about 35 weight percent or the sintered preform and containing a sufficient amount of boron so that the cobalt-base braze alloy has a melting temperature of about 1090°
- C. to about 1230°
C., wherein;
the cobalt-base braze alloy consists of, by weight, about 22.00 to about 24.75% chromium, about 9.0 to about 11.0% nickel, about 6.5 to about 7.6% tungsten, about 3.0 to 4.0% tantalum, about 2.60 to 3.16% boron, about 0.55 to about 0.65% carbon, about 0.15 to 0.30% titanium, about 0.30 to 0.60% zirconium, up to 1.3% iron, up to 0.4% silicon, up to 0.10% manganese, up to 0.015% sulfur, and the balance cobalt and incidental impurities;
the cobalt-base wear-resistant alloy consists of, by weight,about 26.0 to about 30.0% chromium, about 18.0 to about 21.0% tungsten, about 4.0 to about 6.0% nickel, about 0.75 to about 1.25% vanadium, about 0.7 to about 1.0% carbon, up to 3.0% iron, up to 1.0% manganese, up to 0.5% molybdenum, up to 1.0% silicon, up to 0.05% boron, and the balance cobalt and incidental impurities; and
the sintered preform has a porosity of less than 2 volume percent as a result of being subjected to compression to promote fusion and reduce porosity during sintering.
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Accused Products
Abstract
A process for repairing a turbine component of a turbomachine, as well as a sintered preform used in the process and a high gamma-prime nickel-base superalloy component repaired thereby. The sintered preform contains a sintered mixture of powders of a cobalt-base braze alloy and a cobalt-base wear-resistant alloy. The braze alloy constitutes at least about 10 up to about 35 weight percent of the sintered preform and contains a melting point depressant such as boron. The preform is formed by mixing powders of the braze and wear-resistant alloys to form a powder mixture, and then sintering the powder mixture. To use the preform, a surface portion of the turbine component is removed to expose a subsurface portion, followed by diffusion bonding of the preform to the subsurface portion to form a wear-resistant repair material containing the braze alloy dispersed in a matrix of the wear-resistant alloy.
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Citations
5 Claims
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1. A sintered preform consisting essentially of a sintered mixture of powders comprising a cobalt-base braze alloy and a cobalt-base wear-resistant alloy, the cobalt-base braze alloy constituting about 10 to about 35 weight percent or the sintered preform and containing a sufficient amount of boron so that the cobalt-base braze alloy has a melting temperature of about 1090°
- C. to about 1230°
C., wherein;the cobalt-base braze alloy consists of, by weight, about 22.00 to about 24.75% chromium, about 9.0 to about 11.0% nickel, about 6.5 to about 7.6% tungsten, about 3.0 to 4.0% tantalum, about 2.60 to 3.16% boron, about 0.55 to about 0.65% carbon, about 0.15 to 0.30% titanium, about 0.30 to 0.60% zirconium, up to 1.3% iron, up to 0.4% silicon, up to 0.10% manganese, up to 0.015% sulfur, and the balance cobalt and incidental impurities; the cobalt-base wear-resistant alloy consists of, by weight, about 26.0 to about 30.0% chromium, about 18.0 to about 21.0% tungsten, about 4.0 to about 6.0% nickel, about 0.75 to about 1.25% vanadium, about 0.7 to about 1.0% carbon, up to 3.0% iron, up to 1.0% manganese, up to 0.5% molybdenum, up to 1.0% silicon, up to 0.05% boron, and the balance cobalt and incidental impurities; and the sintered preform has a porosity of less than 2 volume percent as a result of being subjected to compression to promote fusion and reduce porosity during sintering. - View Dependent Claims (2, 3, 4, 5)
- C. to about 1230°
Specification