CA2476014A1 - Alloys for high temperature applications, articles made therefrom, and method for repair of articles - Google Patents
Alloys for high temperature applications, articles made therefrom, and method for repair of articles Download PDFInfo
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- CA2476014A1 CA2476014A1 CA002476014A CA2476014A CA2476014A1 CA 2476014 A1 CA2476014 A1 CA 2476014A1 CA 002476014 A CA002476014 A CA 002476014A CA 2476014 A CA2476014 A CA 2476014A CA 2476014 A1 CA2476014 A1 CA 2476014A1
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- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 60
- 239000000956 alloy Substances 0.000 title claims abstract description 60
- 238000000034 method Methods 0.000 title abstract description 16
- 239000011651 chromium Substances 0.000 claims abstract description 40
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 22
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 21
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 21
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims abstract description 19
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000010948 rhodium Substances 0.000 claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims abstract description 9
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 8
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 7
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 6
- 239000011248 coating agent Substances 0.000 claims description 7
- 238000000576 coating method Methods 0.000 claims description 7
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 description 28
- 229910000601 superalloy Inorganic materials 0.000 description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000007792 addition Methods 0.000 description 3
- 238000005304 joining Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 238000010248 power generation Methods 0.000 description 3
- 238000005728 strengthening Methods 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 238000005219 brazing Methods 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000007750 plasma spraying Methods 0.000 description 2
- -1 platinum group metals Chemical class 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000009419 refurbishment Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- YPFNIPKMNMDDDB-UHFFFAOYSA-K 2-[2-[bis(carboxylatomethyl)amino]ethyl-(2-hydroxyethyl)amino]acetate;iron(3+) Chemical compound [Fe+3].OCCN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O YPFNIPKMNMDDDB-UHFFFAOYSA-K 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 238000007749 high velocity oxygen fuel spraying Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
- 230000000930 thermomechanical effect Effects 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C5/00—Alloys based on noble metals
- C22C5/04—Alloys based on a platinum group metal
Abstract
An alloy for use in high temperature applications is presented. The alloy comprises, in atom percent, at least about 50% rhodium (Rh); at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof; from about 5% to about 24% ruthenium (Ru); and from about 1% to about 40% chromium (Cr); wherein the alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in the alloy, respectively.
Articles comprising the alloy and methods employing the alloy for repairing articles are also presented.
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in the alloy, respectively.
Articles comprising the alloy and methods employing the alloy for repairing articles are also presented.
Description
ALLOYS FOR HIGH TEMPERATURE
APPLICATIONS, ARTICLES MADE THEREFROM, AND METHOD FOR REPAIR OF ARTICLES
BACKGROUND OF THE INVENTION
The present invention relates to materials designed to withstand high temperatures.
More particularly, this invention relates to heat-resistant alloys for high-temperature applications, such as, for instance, gas turbine engine components of aircraft engines and power generation equipment. The present invention further relates to methods for repairing articles for high temperature applications.
There is a continuing demand in many industries, notably in the aircraft engine and power generation industries where efficiency directly relates to operating temperature, for alloys that exhibit sufficient levels of strength and oxidation resistance at increasingly higher temperatures. Gas turbine airfoils on such components as vanes and blades are usually made of materials known in the art as °'superalloys." The term "superalloy" is usually intended to embrace iron-, cobalt-, or nickel-based alloys, which include one or more additional elements to enhance high temperature performance, including such non-limiting examples as aluminum, tungsten, molybdenum, titanium, and iron. The term °'based" as used in, for e:Kample, '°nickel-based superalloy°' is widely accepted in the art to mean that the element upon which the alloy is "based" is the single largest elemental component by atom fraction in the alloy composition. Generally recognized to have service capabilities limited to a temperature of about 1200°C, conventional superalloys used in gas turbine airfoils often operate at the upper limits of their practical service temperature range. In typical jet engines, for example, bulk average airfoil temperatures range from about 900°C to about 1000°C, while airfoil leading and trailing edge and tip temperatures can reach about 1150°C or more. At such elevated temperatures, the oxidation process consumes conventional superalloy parts, forming a weak, brittle metal oxide that is prone to chip or spall away from the part.
_1_ Erosion and oxidation of material at the edges of airfoils lead to degradation of turbine efficiency. As airfoils are worn away, gaps between components become excessively wide, allowing gas to leak through the turbine stages without the flow of the gas being converted into mechanical energy. When efficiency drops below specified levels, the turbine must be removed from service for overhaul and refurbishment. A significant portion of this refurbishment process is directed at the repair of the airfoil leading and trailing edges and tips. For example, damaged material is removed and then new material built onto the blade by any of several methods, such as, for example, welding with filler material, welding or brazing new sections onto the existing blade, or by plasma spraying or laser deposition of metal powders onto the blade. The performance of alloys commonly used for repair is comparable or inferior to that of the material of the original component, depending upon the microstructure of the repaired material, its defect density due to processing, and its chemistry. Furthermore, in current practice, the original edge material is made of the same material as the rest of the original blade, often a superalloy based on nickel or cobalt. Because this material was selected to balance the design requirements of the entire blade, it is generally not optimized to meet the special local requirements demanded by conditions at the airfoil leading or trailing edges.
However, maximum temperatures, such as those present at airfoil tips and edges, are expected in future applications to be over about 100°C, at which point many conventional superalloys begin to melt. Clearly, new materials for repair and manufacture must be developed to improve the performance of repaired components and to exploit efficiency enhancements available to new components designed to operate at higher turbine operating temperatures.
BRIEF DESCRIPTION
These and other needs are addressed by embodiments of the present invention.
One embodiment is an alloy comprising, in atom percent, at least about 50% rhodium (Rh); at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof; from about 5% to about 24% ruthenium (Ru); and from about 1 % to about 40% chromium (Cr); wherein the alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr) + 2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in the alloy, respectively.
Another embodiment is an article for use in a high temperature, oxidative environment, comprising the alloy of the present invention.
A third embodiment is a method for repairing an article. The method comprises providing an article, providing a repair material comprising the alloy of the present invention, and joining the repair material to the article.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure I is an isometric view of an airfoil as typically found on a gas turbine engine component.
DETAILED DESCRIPTION
The description herein employs examples taken from the gas turbine industry, particularly the portions of the gas turbine industry concerned with the design, manufacture, operation, and repair of aircraft engines and power generation turbines.
However, the scope of the invention is not limited to only these specific industries, as the embodiments of the present invention are applicable to many and various applications that require materials resistant to high temperature and aggressive environments. Unless otherwise noted, the temperature range of interest where statements and comparisons are made concerning material properties is from about 1000°C to about 1300°C. The term "high temperature" as used herein refers to temperatures above about 1000°C.
The alloy of the present invention balances several competing material requirements, including, for example, cost, strength, ductility, and oxidation resistance.
In _3_ accordance with one embodiment of the present invention, the alloy comprises, in atom percent, at least about SO% rhodium (Rh), at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof, from about 5% to about 24% ruthenium (Ru), and from about 1% to about 40%
chromium (Cr). The alloy comprises less than about 50% by volume of an A3-structured phase, which is a solid solution containing, among other elements, Ru and Cr, and is commonly referred to in the art as "epsilon phase," or s. The presence of this phase strengthens the alloy at the cost of some ductility. The remainder of the alloy comprises a comparatively ductile AI-structured, or face-centered cubic (FCC) phase.
In order to achieve a desirable balance of properties, the composition of the alloy is maintained such that a quantity defined by the expression ([Cr] + 2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in the alloy, respectively. By adding Pd, Cr, and Ru in the above proportions to Rh, the present inventors have discovered a material having suitable high temperature strength (due to solution strengthening obtained from the alloying elements, and in some cases further strengthening due to the presence of the A3-structured phase) with sufficient ductility (due to the substantial proportion of the AI-structured phase) to be formed into useful shapes. Moreover, the cost of the alloy is reduced by adding these alloying elements to the Rh without reducing the oxidation resistance of the material below required levels. Those skilled in the art will appreciate that Pd is less expensive and less dense than Pt, and so in many applications where weight and cost are important considerations, optimal compositions often minimize the use of Pt in favor of Pd. However, Pt may be used in place of some or all of the Pd addition where very high environmental resistance is desired above all other characteristics.
The mix of the above properties and others such as modulus of elasticity can be controlled by varying the relative proportions of constituent elements. For example, Cr additions tend to lower the alloy density while increasing the thermal expansion coefficient, and Ru additions tend to increase strength and modulus. Moreover, maintaining the Cr and Ru in accordance with the expression described above controls the amount of A3-structured phase in the alloy, allowing further control over the strength and ductility of the material. In certain embodiments, the alloy comprises, in atom percent, from about 7% to about 20% ruthenium, and from about 1 % to about 25% chromium. In particular embodiments, the alloy comprises, in atom percent, from about 8% to about 20% ruthenium, and from about 1% to about 10% chromium.
Maintaining alloy composition within these ranges tends to minimize the amount of A3-structured phase, thereby maximizing the ductility, and therefore 'the formability, of the alloy.
Alloys set forth herein as embodiments of the present invention are suitable for production using any of the various known methods of metal production and forming.
Conventional casting, powder metallurgical processing, directional solidification, and single-crystal solidification are non-limiting examples of methods suitable for forming ingots of these alloys. Thermal and thermo-mechanical processing techniques common in the art for the formation of other alloys, including, for instance, forging and heat treating, are suitable for use in maxmfacturing and strengthening the alloys of the present invention.
Another embodiment is an article for use in a high temperature, oxidative environment. The article comprises the alloy described above. The article may be one that has been repaired, or it may be a newly manufactured article. In some embodiments, the article comprises a component of a gas turbine engine, such as, for example, a turbine blade, vane, or a combustor component. Referring to Figure l, a vane or a blade comprises an airfoil 10, which comprises multiple component sections, including a blade tip 11 (in the case where the component is a blade), a leading edge 12, and a trailing edge 13. The alloy of the present invention may be suitably disposed anywhere on the component, including, in certain embodiments, at one or more of the above component sections. In certain embodiments, the article comprises a coating disposed on a substrate, and the coating comprises the alloy.
Having only particular sections (i.e., those sections known to experience the most aggressive stress-temperature combinations) of the airfoil comprise the alloy of the present invention minimizes certain drawbacks of alloys comprising significant amounts of platinum group metals such as, for example, ruthenium, rhodium, and palladium, including their high cost and high density in comparison to conventional airfoil materials. These drawbacks have a reduced effect on the overall component because the comparatively expensive and dense alloy (relative to conventional superalloys) comprises only a fraction of the overall surface area of the component.
The properties of the component are thus "tailored" to the expected localized environments, reducing the need for compromise during the design process and increasing the expected operating lifetimes for new and repaired components:
A further embodiment of the present invention is a method for repairing an article. In this method, an article is provided. The article, in certain embodiments, comprises a component of a gas turbine engine, including, for example, a blade, a vane, or a combustion component. A repair material is provided, and this repair material comprises the alloy described above for previous embodiments of the present invention. This repair material is joined to the article. In some embodiments, joining is accomplished, at least in part, by disposing a coating comprising the repair material onto the article being repaired. Suitable methods for disposing the coating include, for example, thermal spraying, plasma spraying, HVOF spraying, and laser deposition. In other embodiments, the repair material is joined to the substrate by one or more conventional joining processes, including, for example, welding, brazing, or diffusion bonding. Regardless of whether the repair material is in the form of a coating or a solid section, it may be disposed at any section of the article deemed to require the performance characteristics of the repair material. These sections include, for example, the leading and trailing edges of airfoils, and blade tips.
While various embodiments are described herein, it will be appreciated from the specification that various combinations of elements, variations, equivalents, or improvements therein may be made by those skilled in the art, and are still within the scope of the invention as defined in the appended claims.
APPLICATIONS, ARTICLES MADE THEREFROM, AND METHOD FOR REPAIR OF ARTICLES
BACKGROUND OF THE INVENTION
The present invention relates to materials designed to withstand high temperatures.
More particularly, this invention relates to heat-resistant alloys for high-temperature applications, such as, for instance, gas turbine engine components of aircraft engines and power generation equipment. The present invention further relates to methods for repairing articles for high temperature applications.
There is a continuing demand in many industries, notably in the aircraft engine and power generation industries where efficiency directly relates to operating temperature, for alloys that exhibit sufficient levels of strength and oxidation resistance at increasingly higher temperatures. Gas turbine airfoils on such components as vanes and blades are usually made of materials known in the art as °'superalloys." The term "superalloy" is usually intended to embrace iron-, cobalt-, or nickel-based alloys, which include one or more additional elements to enhance high temperature performance, including such non-limiting examples as aluminum, tungsten, molybdenum, titanium, and iron. The term °'based" as used in, for e:Kample, '°nickel-based superalloy°' is widely accepted in the art to mean that the element upon which the alloy is "based" is the single largest elemental component by atom fraction in the alloy composition. Generally recognized to have service capabilities limited to a temperature of about 1200°C, conventional superalloys used in gas turbine airfoils often operate at the upper limits of their practical service temperature range. In typical jet engines, for example, bulk average airfoil temperatures range from about 900°C to about 1000°C, while airfoil leading and trailing edge and tip temperatures can reach about 1150°C or more. At such elevated temperatures, the oxidation process consumes conventional superalloy parts, forming a weak, brittle metal oxide that is prone to chip or spall away from the part.
_1_ Erosion and oxidation of material at the edges of airfoils lead to degradation of turbine efficiency. As airfoils are worn away, gaps between components become excessively wide, allowing gas to leak through the turbine stages without the flow of the gas being converted into mechanical energy. When efficiency drops below specified levels, the turbine must be removed from service for overhaul and refurbishment. A significant portion of this refurbishment process is directed at the repair of the airfoil leading and trailing edges and tips. For example, damaged material is removed and then new material built onto the blade by any of several methods, such as, for example, welding with filler material, welding or brazing new sections onto the existing blade, or by plasma spraying or laser deposition of metal powders onto the blade. The performance of alloys commonly used for repair is comparable or inferior to that of the material of the original component, depending upon the microstructure of the repaired material, its defect density due to processing, and its chemistry. Furthermore, in current practice, the original edge material is made of the same material as the rest of the original blade, often a superalloy based on nickel or cobalt. Because this material was selected to balance the design requirements of the entire blade, it is generally not optimized to meet the special local requirements demanded by conditions at the airfoil leading or trailing edges.
However, maximum temperatures, such as those present at airfoil tips and edges, are expected in future applications to be over about 100°C, at which point many conventional superalloys begin to melt. Clearly, new materials for repair and manufacture must be developed to improve the performance of repaired components and to exploit efficiency enhancements available to new components designed to operate at higher turbine operating temperatures.
BRIEF DESCRIPTION
These and other needs are addressed by embodiments of the present invention.
One embodiment is an alloy comprising, in atom percent, at least about 50% rhodium (Rh); at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof; from about 5% to about 24% ruthenium (Ru); and from about 1 % to about 40% chromium (Cr); wherein the alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr) + 2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in the alloy, respectively.
Another embodiment is an article for use in a high temperature, oxidative environment, comprising the alloy of the present invention.
A third embodiment is a method for repairing an article. The method comprises providing an article, providing a repair material comprising the alloy of the present invention, and joining the repair material to the article.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure I is an isometric view of an airfoil as typically found on a gas turbine engine component.
DETAILED DESCRIPTION
The description herein employs examples taken from the gas turbine industry, particularly the portions of the gas turbine industry concerned with the design, manufacture, operation, and repair of aircraft engines and power generation turbines.
However, the scope of the invention is not limited to only these specific industries, as the embodiments of the present invention are applicable to many and various applications that require materials resistant to high temperature and aggressive environments. Unless otherwise noted, the temperature range of interest where statements and comparisons are made concerning material properties is from about 1000°C to about 1300°C. The term "high temperature" as used herein refers to temperatures above about 1000°C.
The alloy of the present invention balances several competing material requirements, including, for example, cost, strength, ductility, and oxidation resistance.
In _3_ accordance with one embodiment of the present invention, the alloy comprises, in atom percent, at least about SO% rhodium (Rh), at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof, from about 5% to about 24% ruthenium (Ru), and from about 1% to about 40%
chromium (Cr). The alloy comprises less than about 50% by volume of an A3-structured phase, which is a solid solution containing, among other elements, Ru and Cr, and is commonly referred to in the art as "epsilon phase," or s. The presence of this phase strengthens the alloy at the cost of some ductility. The remainder of the alloy comprises a comparatively ductile AI-structured, or face-centered cubic (FCC) phase.
In order to achieve a desirable balance of properties, the composition of the alloy is maintained such that a quantity defined by the expression ([Cr] + 2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in the alloy, respectively. By adding Pd, Cr, and Ru in the above proportions to Rh, the present inventors have discovered a material having suitable high temperature strength (due to solution strengthening obtained from the alloying elements, and in some cases further strengthening due to the presence of the A3-structured phase) with sufficient ductility (due to the substantial proportion of the AI-structured phase) to be formed into useful shapes. Moreover, the cost of the alloy is reduced by adding these alloying elements to the Rh without reducing the oxidation resistance of the material below required levels. Those skilled in the art will appreciate that Pd is less expensive and less dense than Pt, and so in many applications where weight and cost are important considerations, optimal compositions often minimize the use of Pt in favor of Pd. However, Pt may be used in place of some or all of the Pd addition where very high environmental resistance is desired above all other characteristics.
The mix of the above properties and others such as modulus of elasticity can be controlled by varying the relative proportions of constituent elements. For example, Cr additions tend to lower the alloy density while increasing the thermal expansion coefficient, and Ru additions tend to increase strength and modulus. Moreover, maintaining the Cr and Ru in accordance with the expression described above controls the amount of A3-structured phase in the alloy, allowing further control over the strength and ductility of the material. In certain embodiments, the alloy comprises, in atom percent, from about 7% to about 20% ruthenium, and from about 1 % to about 25% chromium. In particular embodiments, the alloy comprises, in atom percent, from about 8% to about 20% ruthenium, and from about 1% to about 10% chromium.
Maintaining alloy composition within these ranges tends to minimize the amount of A3-structured phase, thereby maximizing the ductility, and therefore 'the formability, of the alloy.
Alloys set forth herein as embodiments of the present invention are suitable for production using any of the various known methods of metal production and forming.
Conventional casting, powder metallurgical processing, directional solidification, and single-crystal solidification are non-limiting examples of methods suitable for forming ingots of these alloys. Thermal and thermo-mechanical processing techniques common in the art for the formation of other alloys, including, for instance, forging and heat treating, are suitable for use in maxmfacturing and strengthening the alloys of the present invention.
Another embodiment is an article for use in a high temperature, oxidative environment. The article comprises the alloy described above. The article may be one that has been repaired, or it may be a newly manufactured article. In some embodiments, the article comprises a component of a gas turbine engine, such as, for example, a turbine blade, vane, or a combustor component. Referring to Figure l, a vane or a blade comprises an airfoil 10, which comprises multiple component sections, including a blade tip 11 (in the case where the component is a blade), a leading edge 12, and a trailing edge 13. The alloy of the present invention may be suitably disposed anywhere on the component, including, in certain embodiments, at one or more of the above component sections. In certain embodiments, the article comprises a coating disposed on a substrate, and the coating comprises the alloy.
Having only particular sections (i.e., those sections known to experience the most aggressive stress-temperature combinations) of the airfoil comprise the alloy of the present invention minimizes certain drawbacks of alloys comprising significant amounts of platinum group metals such as, for example, ruthenium, rhodium, and palladium, including their high cost and high density in comparison to conventional airfoil materials. These drawbacks have a reduced effect on the overall component because the comparatively expensive and dense alloy (relative to conventional superalloys) comprises only a fraction of the overall surface area of the component.
The properties of the component are thus "tailored" to the expected localized environments, reducing the need for compromise during the design process and increasing the expected operating lifetimes for new and repaired components:
A further embodiment of the present invention is a method for repairing an article. In this method, an article is provided. The article, in certain embodiments, comprises a component of a gas turbine engine, including, for example, a blade, a vane, or a combustion component. A repair material is provided, and this repair material comprises the alloy described above for previous embodiments of the present invention. This repair material is joined to the article. In some embodiments, joining is accomplished, at least in part, by disposing a coating comprising the repair material onto the article being repaired. Suitable methods for disposing the coating include, for example, thermal spraying, plasma spraying, HVOF spraying, and laser deposition. In other embodiments, the repair material is joined to the substrate by one or more conventional joining processes, including, for example, welding, brazing, or diffusion bonding. Regardless of whether the repair material is in the form of a coating or a solid section, it may be disposed at any section of the article deemed to require the performance characteristics of the repair material. These sections include, for example, the leading and trailing edges of airfoils, and blade tips.
While various embodiments are described herein, it will be appreciated from the specification that various combinations of elements, variations, equivalents, or improvements therein may be made by those skilled in the art, and are still within the scope of the invention as defined in the appended claims.
Claims (12)
1. An alloy comprising, in atom percent:
at least about 50% rhodium (Rh);
at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof;
from about 5% to about 24% ruthenium (Ru); and from about 1 % to about 40% chromium (Cr);
wherein said alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
at least about 50% rhodium (Rh);
at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof;
from about 5% to about 24% ruthenium (Ru); and from about 1 % to about 40% chromium (Cr);
wherein said alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in said alloy, respectively.
2. The alloy of claim 1, comprising in atom percent from about 7% to about 20% ruthenium, and from about 1% to about 25% chromium.
2. The alloy of claim 1, comprising in atom percent from about 7% to about 20% ruthenium, and from about 1% to about 25% chromium.
3. The alloy of claim 1, comprising in atom percent from about 8% to about 20% ruthenium, and from about 1 % to about 10% chromium.
4. An article for use in a high temperature, oxidative environment, said article comprising:
an alloy comprising, in atom percent, at least about 50% rhodium (Rh);
at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof;
from about 5% to about 24% ruthenium (Ru); and from about 1% to about 40% chromium (Cr);
wherein said alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in said alloy, respectively,.
an alloy comprising, in atom percent, at least about 50% rhodium (Rh);
at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof;
from about 5% to about 24% ruthenium (Ru); and from about 1% to about 40% chromium (Cr);
wherein said alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in said alloy, respectively,.
5. The article of claim 4, wherein said article comprises a coating disposed on a substrate, and wherein said coating comprises said alloy.
6. The article of claim 4, wherein said article comprises a component of a gas turbine assembly.
7. The article of claim 6, wherein said component comprises at least one of a turbine blade, a turbine vane, and a combustor component.
8. The article of claim 7, wherein said alloy is disposed at at least one component section selected from the group consisting of a leading edge (12), a trailing edge (13), and a blade tip (11).
9. The article of claim 4, wherein said alloy comprises from about 7% to about 20% ruthenium, and from about 1% to about 25% chromium.
10. The article of claim 4, wherein said alloy comprises from about 8% to about 20% ruthenium, and from about 1 % to about 10% chromium.
11. The article of claim 4, wherein said article comprises a repaired article.
12. A gas turbine engine component comprising:
an alloy comprising, in atom percent, at least about 50% rhodium (Rh);
at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof;
from about 7% to about 20% ruthenium (Ru); and from about 1% to about 25% chromium (Cr);
wherein said alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in said alloy, respectively; wherein said turbine engine component comprises one of a blade and a vane and said alloy is disposed in at least one section of said component selected from the group consisting of a leading edge (12), a trailing edge (13), and a blade tip (11).
an alloy comprising, in atom percent, at least about 50% rhodium (Rh);
at least about 5% of a metal selected from the group consisting of platinum (Pt), palladium (Pd), and combinations thereof;
from about 7% to about 20% ruthenium (Ru); and from about 1% to about 25% chromium (Cr);
wherein said alloy comprises less than about 50% by volume of an A3-structured phase, and wherein the quantity defined by the expression ([Cr] +
2[Ru]) is in the range from about 25% to about 50%, where [Ru] and [Cr] are the atom percentages of ruthenium and chromium in said alloy, respectively; wherein said turbine engine component comprises one of a blade and a vane and said alloy is disposed in at least one section of said component selected from the group consisting of a leading edge (12), a trailing edge (13), and a blade tip (11).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/636,407 | 2003-08-07 | ||
| US10/636,407 US20050031482A1 (en) | 2003-08-07 | 2003-08-07 | Alloys for high temperature applications, articles made therefrom, and method for repair of articles |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2476014A1 true CA2476014A1 (en) | 2005-02-07 |
Family
ID=33552954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002476014A Abandoned CA2476014A1 (en) | 2003-08-07 | 2004-07-29 | Alloys for high temperature applications, articles made therefrom, and method for repair of articles |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US20050031482A1 (en) |
| EP (1) | EP1505165A1 (en) |
| JP (1) | JP2005054271A (en) |
| BR (1) | BRPI0403208A (en) |
| CA (1) | CA2476014A1 (en) |
| SG (1) | SG109007A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7208232B1 (en) * | 2005-11-29 | 2007-04-24 | General Electric Company | Structural environmentally-protective coating |
| RU2502815C1 (en) * | 2012-12-18 | 2013-12-27 | Юлия Алексеевна Щепочкина | Coin making alloy |
| RU2514361C1 (en) * | 2013-06-14 | 2014-04-27 | Юлия Алексеевна Щепочкина | Alloy |
| GB201620687D0 (en) * | 2016-12-05 | 2017-01-18 | Johnson Matthey Plc | Rhodium alloys |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0025200D0 (en) * | 2000-10-13 | 2000-11-29 | Xeikon Nv | Toner composition |
| US6623692B2 (en) * | 2001-08-29 | 2003-09-23 | General Electric Company | Rhodium-based alloy and articles made therefrom |
| US6582534B2 (en) * | 2001-10-24 | 2003-06-24 | General Electric Company | High-temperature alloy and articles made therefrom |
| US6554920B1 (en) * | 2001-11-20 | 2003-04-29 | General Electric Company | High-temperature alloy and articles made therefrom |
-
2003
- 2003-08-07 US US10/636,407 patent/US20050031482A1/en not_active Abandoned
-
2004
- 2004-07-29 CA CA002476014A patent/CA2476014A1/en not_active Abandoned
- 2004-07-30 EP EP04254572A patent/EP1505165A1/en not_active Withdrawn
- 2004-08-05 BR BR0403208-0A patent/BRPI0403208A/en not_active IP Right Cessation
- 2004-08-06 SG SG200404414A patent/SG109007A1/en unknown
- 2004-08-06 JP JP2004230069A patent/JP2005054271A/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| US20050031482A1 (en) | 2005-02-10 |
| SG109007A1 (en) | 2005-02-28 |
| EP1505165A1 (en) | 2005-02-09 |
| BRPI0403208A (en) | 2005-05-24 |
| JP2005054271A (en) | 2005-03-03 |
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| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |