METHOD OF ELECTROFORMING A COMPONENT

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001]This application claims priority to Indian Provisional Application No. 20/241,1030197, filed Apr. 15, 2024, the disclosure of which is hereby incorporated by reference in its entirety as though fully set forth herein.

TECHNICAL FIELD

[0002]The disclosure generally relates to a method of forming a component and, more specifically, a method of forming a high-strength component.

BACKGROUND

[0003]Turbine engines, and particularly gas or combustion turbine engines, are rotary engines that extract energy from a flow of combusted gases passing through the engine in a series of compressor stages, which include pairs of rotating blades and stationary vanes, through a combustor, and then onto a multitude of turbine stages, also including multiple pairs of rotating blades and stationary vanes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004]A full and enabling disclosure of the aspects of the present description, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which refers to the appended Figs., in which:

[0005]FIG. 1 is a schematic cross-sectional view of a gas turbine engine with a duct assembly.

[0006]FIG. 2 is a schematic illustration of an electroforming bath for forming a component according to various aspects of the disclosure.

[0007]FIG. 3 is a schematic cross-sectional view of a portion of the component of FIG. 2 according to various aspects of the disclosure.

[0008]FIG. 4 is a schematic cross-sectional view of a portion of the component of FIG. 3 with a surface layer according to various aspects of the disclosure.

[0009]FIG. 5 is a schematic cross-sectional view of an upper portion of the component of FIG. 4 after a first heat-treatment according to various aspects of the disclosure.

[0010]FIG. 6 is a schematic cross-sectional view of an upper portion of the component of FIG. 5 after a second heat-treatment according to various aspects of the disclosure.

[0011]FIG. 7A graphically illustrates an exemplary heat-treating schedule according to various aspects of the disclosure.

[0012]FIG. 7B graphically illustrates a second exemplary heat-treating schedule according to various aspects of the disclosure.

[0013]FIG. 8 is a flowchart diagram illustrating a method of forming the component according to various aspects of the disclosure.

[0014]FIG. 9 is a flowchart diagram illustrating a method of repairing a component according to various aspects of the disclosure.

DETAILED DESCRIPTION

[0015]Higher operating temperatures for gas turbine engines are continuously being sought to improve their efficiency. However, as operating temperatures increase, the high temperature durability of the components of the engine must correspondingly increase. Significant advances in high temperature capabilities have been achieved through the formulation of superalloys. While superalloys have found wide use for components used throughout gas turbine engines, and especially in the higher temperature sections, alternative options are desired for both weight, cost, and processing reasons (for example, the hardness of superalloys makes them difficult to machine).

[0016]Aspects of present disclosure relate to a high-strength component. More specifically, aspects of the disclosure relate to high-strength alloy components formed via a multi-step method including, electroforming and a secondary process such as x-iding. As used herein, “x-iding” is a deposition process that results in a surface layer of a particular element or alloy. By way of non-limiting example, x-iding where the resulting surface layer includes aluminum could be considered aluminiding.

[0017]While it should be understood that the component can be any suitable component, much of the disclosure will focus on a duct assembly or conduit for providing a flow of fluid from one portion of a gas turbine engine to another portion of the gas turbine engine. Gas turbine engines have been used for land and nautical locomotion and power generation, but are most commonly used for aeronautical applications such as for airplanes, including helicopters. In airplanes, gas turbine engines are used for propulsion of the aircraft. It will be understood, however, that the disclosure is not so limited and can have general applicability in non-aircraft applications, such as other mobile applications and non-mobile industrial, commercial, and residential applications. Further still, such methods can be utilized to make any suitable high-strength components.

[0018]An electroforming process can create, generate, or otherwise form a metallic layer on a component or mandrel. In one example of the electroforming process, a mold or base for the desired component can be submerged in an electrolytic liquid and electrically charged. The electric charge of the mold or base can attract an oppositely-charged electroforming material through the electrolytic solution or electrolytic fluid. The attraction of the electroforming material to the mold or base ultimately deposits the electroforming material on the exposed surfaces of the mold or base, creating an external metallic layer and forming a net shape part. Electroformed alloys are currently limited to solid-solution strengthened alloys. Solid solution strengthening is a type of alloying that can be used to improve the strength of a pure metal. The technique works by adding atoms of one element to the crystalline lattice of another element, forming a solid solution. Conventional electroforming processes can only produce a simple alloy containing two or three elements, wherein the choice of elements is restricted. Further, conventional electroforming cannot produce a superalloy which contains multiple elements or include active elements like Al or Ti.

[0019]Therefore, aspects of the disclosure present a process to add additional performance features to the electroformed part. This can include, among other things, higher-strength at high temperatures than would not be achievable with the electroformed part without the post processing. By way of a non-limiting example, the electroformed part can be precipitation strengthened by the gamma-prime forming elements such as Al, Si, Ta, Ti, etc. The disclosure provides a method for introducing these elements via a secondary process post electroforming as they currently cannot be incorporated in the electroforming process.

[0020]As used herein “a set” can include any number of the respectively described elements, including only one element. Additionally, all directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, aft, etc.) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the present disclosure. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to one another. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto can vary.

[0021]In the present disclosure, when a layer is being described as “on” or “over” another layer or substrate, it is to be understood that the layers can either be directly contacting each other or have another layer or feature between the layers, unless expressly stated to the contrary. Thus, these terms are simply describing the relative position of the layers to each other and do not necessarily mean “on top of” since the relative position above or below depends upon the orientation of the device to the viewer.

[0022]The exemplary drawings are for purposes of illustration only and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto can vary.

[0023]FIG. 1 is a schematic cross-sectional diagram of a gas turbine engine 10 for an aircraft. The engine 10 has a generally longitudinally extending axis or centerline 12 extending from forward 14 to aft 16. The engine 10 includes, in downstream serial flow relationship, a fan section 18 including a fan 20, a compressor section 22 including a booster or low pressure (LP) compressor 24 and a high pressure (HP) compressor 26, a combustion section 28 including a combustor 30, a turbine section 32 including a HP turbine 34, and a LP turbine 36, and an exhaust section 38.

[0024]The fan section 18 includes a fan casing 40 surrounding the fan 20. The fan 20 includes a set of fan blades 42 disposed radially about the centerline 12. The HP compressor 26, the combustor 30, and the HP turbine 34 form a core 44 of the engine 10, which generates combustion gases. The core 44 is surrounded by core casing 46, which can be coupled with the fan casing 40.

[0025]An HP shaft or spool 48 disposed coaxially about the centerline 12 of the engine 10 drivingly connects the HP turbine 34 to the HP compressor 26. A LP shaft or spool 50, which is disposed coaxially about the centerline 12 of the engine 10 within the larger diameter annular HP spool 48, drivingly connects the LP turbine 36 to the LP compressor 24 and fan 20. The portions of the engine 10 mounted to and rotating with either or both of the spools 48, 50 are also referred to individually or collectively as a rotor 51.

[0026]The LP compressor 24 and the HP compressor 26 respectively include a set of compressor stages 52, 54, in which a set of compressor blades 56, 58 rotate relative to a corresponding set of static compressor vanes 60, 62 (also called a nozzle) to compress or pressurize the stream of fluid passing through the stage. In a single compressor stage 52, 54, multiple compressor blades 56, 58 can be provided in a ring and can extend radially outwardly relative to the centerline 12, from a blade platform to a blade tip, while the corresponding static compressor vanes 60, 62 are positioned downstream of and adjacent to the rotating blades 56, 58. It is noted that the number of blades, vanes, and compressor stages shown in FIG. 1 were selected for illustrative purposes only, and that other numbers are possible. The blades 56, 58 for a stage of the compressor can be mounted to a disk 53, which is mounted to the corresponding one of the HP and LP spools 48, 50, respectively, with stages having their own disks. The vanes 60, 62 are mounted to the core casing 46 in a circumferential arrangement about the rotor 51.

[0027]The HP turbine 34 and the LP turbine 36 respectively include a set of turbine stages 64, 66, in which a set of turbine blades 68, 70 are rotated relative to a corresponding set of static turbine vanes 72, 74 (also called a nozzle) to extract energy from the stream of fluid passing through the stage. In a single turbine stage 64, 66, multiple turbine blades 68, 70 can be provided in a ring and can extend radially outwardly relative to the centerline 12, from a blade platform to a blade tip, while the corresponding static turbine vanes 72, 74 are positioned upstream of and adjacent to the rotating blades 68, 70. It is noted that the number of blades, vanes, and turbine stages shown in FIG. 1 were selected for illustrative purposes only, and that other numbers are possible.

[0028]In operation, the rotating fan 20 supplies ambient air to the LP compressor 24, which then supplies pressurized ambient air to the HP compressor 26, which further pressurizes the ambient air. The pressurized air from the HP compressor 26 is mixed with fuel in the combustor 30 and ignited, thereby generating combustion gases. Some work is extracted from these gases by the HP turbine 34, which drives the HP compressor 26. The combustion gases are discharged into the LP turbine 36, which extracts additional work to drive the LP compressor 24, and the exhaust gas is ultimately discharged from the engine 10 via the exhaust section 38. The driving of the LP turbine 36 drives the LP spool 50 to rotate the fan 20 and the LP compressor 24.

[0029]Some of the air from the compressor section 22 can be bled off via one or more duct assemblies 80 (shown schematically), and be used for cooling of portions, especially hot portions, such as the HP turbine 34, or used to generate power or run environmental systems of the aircraft such as the cabin cooling/heating system or the deicing system. In the context of a gas turbine engine, the hot portions of the engine are normally downstream of the combustor 30, especially the turbine section 32, with the HP turbine 34 being the hottest portion as it is directly downstream of the combustion section 28. Air that is drawn off the compressor and used for these purposes is known as bleed air.

[0030]Additionally, the ducts, or metal tubular elements thereof, can also be a fluid delivery system for routing a fluid through the engine 10, including through the duct assemblies 80. The duct assemblies 80, such as air duct or other ducting assemblies leading either internally to other portions of the gas turbine engine 10 or externally of the gas turbine engine 10, can also include one or more metal tubular elements or metallic tubular elements forming ducts or conduits configured to convey fluid from a first portion of the engine 10 to another portion of the engine 10. In addition, duct assemblies 80 leading internally to portions of the gas turbine 10 are exposed to high temperatures during operation. Components formed by the process disclosed herein that includes electroforming, x-iding, and a heat treatment can provide a component having advantages such as greater strength properties, increased high-temperature resistance, reduced corrosion, oxidation resistance, or a combination thereof.

[0031]An example electroforming process is illustrated by way of an electrodeposition bath 91 in FIG. 2. As used herein, “electroforming” or “electrodeposition” can include any process for building, forming, growing, or otherwise creating a metal layer over another substrate or base. Non-limiting examples of electrodeposition can include electroforming, electroless forming, electroplating, or a combination thereof. While the remainder of the disclosure is directed to electroforming, any and all electrodeposition processes are equally applicable. An exemplary bath tank 82 carries a solution 84. The solution 84 can include an aqueous electrolyte containing dissolved salts. The solution 84, in one non-limiting example, can include a single metal ion constituent solution. By way of a further non-limiting example this can include a solution from which a nickel alloy can be deposited. In another non-limiting example, a nickel-cobalt alloy can be deposited from an electrolyte solution containing both nickel and cobalt ions.

[0032]As shown in FIG. 2, an anode 86 spaced from a cathode 95 is provided in the bath tank 82 and submerged in the solution 84. The anode 86 can be sacrificial or consumable anode or an inert anode. While one anode is shown, it should be understood that the bath tank 82 can include any number of anodes 86 as desired. A substrate, base, or component is illustrated, by way of non-limiting example, as a sacrificial mandrel 100. The sacrificial mandrel 100 is utilized in forming at least a portion of a component 96. In the illustrated example, the component 96 is shown as a duct 97, suitable for use in by way of non-limiting example, the duct assembly 80. The sacrificial mandrel 100 itself can be formed via additive manufacturing, injection molding, or any other suitable process. The sacrificial mandrel 100 can include, by way of non-limiting examples, materials such as plastics/polymers, wax, or aluminum, and in any desired configuration such as solid, hollow, or foam. The component 96 can be, by way of non-limiting example, any component in or coupled to the gas turbine engine 10. In other words, the component 96 can be in the compressor section 22, the combustion section 28, the turbine section 32, or external of the gas turbine engine 10, such as, but not limited to, tubes or ducts. While illustrated as the duct 97, the component 96 can be a blade or vane or components that hang or otherwise couple to the blade or vane from one or more of the set of compressor blades 56, 58, the set of static compressor vanes 60, 62, the multiple turbine blades 68, 70, or the static turbine vanes 72, 74. The duct 97 can form the cathode 95, having electrically conductive material. It is also contemplated that a conductive spray or similar treatment can be provided to the sacrificial mandrel 100 to facilitate formation of the cathode 95. In addition, while illustrated as one cathode 95, it should be appreciated that one or more cathodes are contemplated for use in the bath tank 82.

[0033]A controller 90, which can include a power supply, can electrically couple to the anode 86 and the cathode 95 by electrical conduits 92 to form a circuit via the conductive metal constituent solution 84. Optionally, a switch 94 or sub-controller can be included along the electrical conduits 92, between the controller 90 and the anode 86 and the cathode 95.

[0034]During operation, a current can be supplied from the anode 86 to the cathode 95 to electroform or electrodeposit a monolithic body on the sacrificial mandrel 100. More specifically metal ions from the solution 84 can be deposited as metal on the sacrificial mandrel 100 to form a metallic layer 98. During supply of the current, nickel, iron, or nickel and cobalt from the solution 84 form the metallic layer 98 such as, but not limited to, iron (Fe) metallic layer, cobalt (Co) metallic layer, nickel (Ni) metallic layer, nickel-cobalt (NiCo) metallic layer, or nickel-cobalt-phosphorous metallic layer over the sacrificial mandrel 100 to form the duct 97. That is, the metallic layer 98 by way of non-limiting example, can be one or more of elemental Fe, Co, Ni, NiCo, NiCoP, or alloys thereof. The sacrificial mandrel 100 can then be removed, recycled, or “sacrificed,” from the duct 97, including by way of melting, such as through application of heat to the sacrificial mandrel 100, or by dissolving, e.g. a chemical dissolving process, in non-limiting examples.

[0035]FIG. 3 is a schematic cross-sectional view of a portion of the duct 97 removed from the sacrificial mandrel 100. The metallic layer 98 forms a duct wall 104. More specifically, the duct wall 104 is an annular duct wall having an exterior surface 103 and an interior surface 105 bounding an internal passage 106. The duct wall 104 includes a metallic layer thickness 102. It will be understood that the metallic layer thickness 102 is bounded by the exterior surface 103 and the interior surface 105. In a non-limiting example, the metallic layer thickness 102 can be in a range from 25 micrometers (μm) to 5000 micrometers (μm). This range can provide structural rigidity while adding a minimal weight to the part. In a non-limiting example, the metallic layer thickness can be in a range of 250 micrometers (μm) to 5000 micrometers (μm) for applications to create thicker components 96 with the surface strengthened. In another example, the metallic layer thickness 102 can be in a range from 25 micrometers (μm) to 250 micrometers (μm) to create components 96 strengthened across the entire metallic layer thickness 102. That is, components 96 with the metallic layer thickness 102 that is in a range from 25 micrometers (μm) to 250 micrometers (μm) provide the required structural stiffness while minimizing cost of material and weight. It is contemplated in another non-limiting example, that the metallic layer thickness 102 can have a variable metallic layer thickness through portions of the duct 97. The term “variable thickness” used herein, is defined as non-constant or a not consistent thickness along the direction of the length L of the duct 97. It is further contemplated, that the duct 97 can be at least one of non-linear or non-circular. Once the duct 97 is removed from the electrodeposition bath 91, the duct 97 can be moved to a layer forming system 99 and then a heat-treating device 101, described further in FIG. 4 and FIG. 5. Optionally, the duct 97 is removed from the sacrificial mandrel 100 prior to being moved to the layer forming system 99 or the heat-treating device 101.

[0036]FIG. 4 illustrates the duct 97 after a surface layer 108 has been deposited on the exterior surface 103 of the duct wall 104 by the layer forming system 99 (FIG. 2). It is contemplated that the composition of the surface layer 108 can include at least one alloying element. The at least one alloying element is selected from a group of: aluminum (Al), silicon (Si), tantalum (Ta), titanium (Ti), chromium (Cr), and boron (B). It is contemplated in a non-limiting example, that the surface layer 108 can include multiple alloying elements including, by way of further non-limiting example that the multiple alloying elements are selected from the group of: Al, Si, Ta, Ti, Cr, and B. It is contemplated that the surface layer 108 can be formed on the interior surface 105 of the duct wall 104 as well as the exterior surface 103; however, the remainder of the application illustrates the surface layer 108 only on the exterior surface 103 of the duct wall 104.

[0037]In a non-limiting example, the layer deposition system 99 (FIG. 2) can include any x-iding system. That is, the surface layer 108 can be deposited by x-iding wherein the “x” in x-iding can include at least one of Al, Si, Ta, Ti, Cr, or B. The x-iding deposition process can include any suitable deposition process including vapor phase deposition or pack cementation by way of non-limiting examples. The surface layer 108 deposited via the x-iding process has a surface layer thickness 110. In a non-limiting example, the surface layer 108 has a thickness in a range of 12.5 micrometers (μm) to 130 micrometers (μm). That is, the surface layer 108 can fully infiltrate the metallic layer 102 without leaving a residual layer of the surface layer 108 when the surface layer thickness is in range a of 12.5 micrometers (μm) to 130 micrometers (μm).

[0038]The metallic layer 98 can be welded prior to forming a surface layer. That is, the metallic layer 98 of the duct 97 can be machined to include interior holes and channels of small dimensions or be joined with another part prior to the forming of the surface layer, which includes elements that are less conducive to welding. Once the duct 97 is deposited with the surface layer 108, the duct 97 can be moved to the heat-treatment device 101 (FIG. 2), described further in FIG. 5.

[0039]FIG. 5 is a schematic cross-sectional view of the duct wall 104 after completion of a first heat-treatment in the heat-treatment device 101 (FIG. 2). In a non-limiting example, the heat-treatment device 101 (FIG. 2) can include an oven or a furnace. It will be understood that the duct 97 can go through at least one heat treatment following formation of the surface layer 108 (FIG. 4). The at least one heat treatment can include stress equalizing, stress relieving, annealing, solution annealing, tempering, age hardening, precipitation hardening, or diffusion, in some non-limiting examples. It is contemplated that the at least one heat treatment can include a first heat treatment performed at a first temperature. The remainder of the disclosure will discuss a two-step heat treating process, but it will be understood that any suitable heat treating can be utilized.

[0040]In a non-limiting example, the duct 97 including the surface layer 108 (FIG. 4) is heated at a treatment temperature in a range of 500° C. to 1200° C. during the first heat-treatment. That is, the treatment temperature in a range of 500° C. to 1200° C. is the range in which Gamma-prime precipitate phase is formed. The first heat-treatment forms a distribution of particles 112 of the at least one alloying element throughout the metallic layer thickness 102 (FIG. 4) of the duct wall 104. That is, the at least one alloying element infiltrates the duct wall 104. The duct wall 104 has a relatively high concentration of particles 112 of the at least one alloying element near the exterior surface 103 (FIG. 3) and a relatively low concentration of particles 112 of at least one alloying element near the interior surface 105. In a non-limiting example, the first heat-treatment is further configured to homogenize the distribution of the particles 112 of the at least one alloying element within the duct wall 104. It is understood that, in some examples, the particles 112 can have a uniform or non-uniform arrangement, distribution, or the like after performing the first heat treatment.

[0041]In another non-limiting example, the first heat treatment creates a distribution of formed gamma-prime particles. Gamma-prime particles are an intermetallic phase that precipitate out of the alloy matrix in a second heat treatment which is described further in FIG. 6. Gamma-prime precipitate phase can include nickel-aluminide (Ni₃Al) or nickel-titanium (Ni₃Ti) by way of non-limiting examples.

[0042]FIG. 6 is a schematic cross-sectional view of a portion the duct wall 104 after completion of a second heat-treatment following the first heat-treatment illustrated in FIG. 5. It is understood that the second heat-treatment can form precipitates 114 within the duct wall 104. The formation of these precipitates leads to precipitate strengthening which enables the material to have high strength at high temperatures. Precipitation strengthening relies on changes in solid solubility and temperature to produce fine particles of an intermetallic phase. The fine particles of the intermetallic phase impede the movement of dislocations, or defects in a crystal lattice. The impeded movement of dislocations serves to harden a material. Precipitation in solids can produce many different sizes of particles, which have different properties. In order to allow complete precipitation to take place, alloys must be kept at a predetermined elevated temperature for sufficient time. This heat-treatment step is typically referred to as an aging heat-treatment.

[0043]In the illustrated example, formation of the precipitates 114 can be limited to locations of the particles 112 and not within the entire duct wall 104. However, the precipitates 114 can form homogeneously across the entire duct wall 104. It is further contemplated that, in some examples, the second heat-treatment can be performed once, forming a single-step aging process, or performed multiple times to form a multi-step aging process.

[0044]FIG. 7A graphically illustrates an exemplary heat-treating schedule that can be performed on a component such as the duct 97, by the heat-treating device 101 (FIG. 2). In the non-limiting example illustrated, the first heat-treatment starts at 116 where the temperature of the component is at ambient temperature. The temperature of the component gradually increases to a range of 500° C. to 1200° C., at 118. This temperature can be held for a duration such as by way of non-limiting example, of 24 hours. At 120, the temperature of the component can be equal to the temperature of the component at 118 or can be within a range of 10% to 15% of the temperature of the component at 118. The temperature of the component is decreased to ambient temperature. In a non-limiting example, the temperature of the component can be decreased by one or more of water quenching, air cooling, or furnace cooling.

[0045]At 122, the second heat-treatment is performed. It is contemplated in a non-limiting example, that the start of the second heat-treatment can be performed immediately after the first heat-treatment. However, it is contemplated in another non-limiting example, that the second heat-treatment can be performed a predetermined amount of time after the first heat-treatment. In the exemplary graphical illustration shown, the second heat-treatment is a single-step aging process. The temperature of the component is increased to a range of 500° C. to 1200° C. at 124. In a non-limiting example, the temperature of the component at 124 can be less than the temperature of the component at 118 and 120 of the first heat treatment. Further, the second heat-treatment is performed for a predetermined duration, such as for example, 8 hours. The component is held at the elevated temperature from 124 to 126. At 126, the temperature of the component can be equal to the temperature of the component at 124 or can be within a range of 10% to 15% of the temperature of the component at 124. The temperature of the component is then decreased to ambient temperature at 128. In a non-limiting example, the temperature of the component can be decreased by one or more of water quenching, air cooling, or furnace cooling.

[0046]FIG. 7B graphically illustrates another exemplary heat-treating schedule that can be performed on a component, such as the duct 97. In the non-limiting example illustrated, the first heat-treatment starts at 130 where the temperature of the component is at ambient temperature. The temperature of the component gradually increases to a range of 500° C. to 1200° C. at 132. This temperature can be held for a duration such as by way of non-limiting example, of 24 hours. At 134, the temperature of the component can be equal to the temperature of the component at 132 or can be within a range of 10% to 15% of the temperature of the component at 132. At 136, the temperature of the component is decreased to ambient temperature. In a non-limiting example, the temperature of the component can be decreased by one or more of water quenching, air cooling, or furnace cooling.

[0047]At 136, the second heat-treatment is performed. It is contemplated in a non-limiting example, that the start of the second heat-treatment can be performed immediately after the first heat-treatment. However, it is contemplated in another non-limiting example, that the second heat-treatment can be performed a predetermined amount of time after the first heat-treatment. In the exemplary graphical illustration shown, the second heat-treatment is a multi-step aging process. At 138, the temperature of the component is increased to a range of 500° C. to 1200° C. In a non-limiting example, the temperature of the component at 138 can be less than the temperature of the component at 132 and 134 of the first heat treatment. Further, a first step of the multi-step aging a process is performed for a predetermined duration, such as for example, 4 hours. The component is held at the elevated temperature from 138 to 140. At 140, the temperature of the component can be equal to the temperature of the component at 138 or can be within a range of 10% to 15% of the temperature of the component at 138. At 142, the temperature of the component is decreased. For example, the temperature can be decreased by 25% to 50% of the temperature of the component at 140. In the non-limiting example shown, the rate of decrease of the temperature of the component between 140 and 142 has a linear decay. However, it is contemplated in another non-limiting example, that the rate of decrease of the temperature of the component between 140 and 142 can have an exponential decay, as illustrated at 143.

[0048]At 142, a second step of the multi-step aging process is performed for a predetermined duration, such as for example, 4 hours. In another non-limiting example, the temperature of the component can be decreased by one or more of water quenching, air cooling, or furnace cooling. At 144, the temperature of the component can be equal to the temperature of the component at 118 or within a range of 10% to 15% of the temperature of the component at 142. At 146, the temperature of the component is decreased to ambient temperature.

[0049]FIG. 8 illustrates a method 200 of forming the component 96 such as the duct 97. At 202, a body, such as the duct wall 104 (FIG. 3), can be formed by way of electrodeposition of the metallic layer 98 (FIG. 2) over an exposed surface of the sacrificial mandrel 100 (FIG. 2). At 204, the sacrificial mandrel 100 (FIG. 2) can be removed including by melting or dissolving. At 206, the surface layer 108 (FIG. 4) including at least one alloying element is formed on the duct wall 104 (FIG. 3), where the at least one alloying element can include Al, Si, Ta, Ti, Cr, or B. At 208 the duct wall 104 (FIG. 4) with the surface layer 108 (FIG. 4) is heat treated by the first heat-treatment, where the first heat-treatment is configured to infiltrate the at least one alloying element into the duct wall 104 (FIG. 5). Optionally, at 210 the component 96 is heat treated in the second heat-treatment, where the second heat-treatment is configured to form precipitates in the duct wall 104 (FIG. 6). In a non-limiting example, during the formation of precipitates, appropriate thermodynamic and diffusion kinetics models can be used to determine the amount of gamma-prime precipitate phase, thereby obtaining the desired strength and balance of properties.

[0050]A specific example may prove useful but should not be seen as limiting on the disclosure. In such an example a 250 micrometers (μm) thick Ni matrix can be formed via electroforming. For such a thickness it has been determined that approximately 69 micrometers (μm) of an Al surface layer is desirable for infiltration of the entire surface layer 108 (FIG. 4) and homogenous distribution of precipitates 114 (FIG. 5) across the metallic layer thickness 102 (FIG. 3). For example, such surface layer can be deposited onto the Ni metallic layer via vapor phase aluminiding. For example, a hydrogen halide gas, such as hydrogen chloride or hydrogen fluoride, is contacted with aluminum metal or an aluminum alloy to form the corresponding aluminum halide gas.

[0051]In a non-limiting example, if the metallic layer 98 (FIG. 4) is elemental Ni and the at least one alloying element in the surface layer 108 (FIG. 4) is Al, the first heat-treatment infiltrates the Al into the metallic layer 98 and the second heat-treatment creates a strengthened precipitate of nickel-aluminide (Ni₃Al). The volume of gamma-prime precipitate phase of Ni₃Al in the metallic layer 98 dictates the strength of the component 96. If all of the Al is uniformly infiltrated, in a non-limiting example, into the Ni-matrix via a heat-treatment step, and then the appropriate aging heat-treatment is carried out approximately 50 mol. % of Ni₃Al (strengthening precipitate) is achieved. It will be understood that this is only a simple illustrative example, and a similar strategy can used to infiltrate other active alloying elements for achieving the right chemistry, microstructure, and therefore balance of properties. Other elements may be doped into the surface layer from a corresponding gas, if desired. The deposition technique allows alloying elements to be co-deposited into the surface layer if desired, from the halide gas. It will be further understood that one or more alloying elements can be created as a surface layer depending on the balance of properties required in the final component or multiple surface layers with appropriate heat treatment steps can be utilized to obtain the desired balance of properties for the component.

[0052]FIG. 9 is a flowchart diagram illustrating a method 300 of repairing the component 96 such as the duct 97 according to various aspects of the disclosure. The method 300 can be utilized to repair a component having performed at least one cycle of operation. The component can include, for example, foreign object damage or other physical aspects that require the component to be repaired. At 302, the surface layer 108 (FIG. 4) of duct 97 can be removed, including chemical stripping such as submerging the component 96 in a chemical bath of inorganic acids, sand or water jet blasting, or any combination thereof. At 304, the duct 97 stripped to the metallic layer 98 (FIG. 3) can be welded or brazed to repair portions of the duct wall 104 (FIG. 3). At 306, the surface layer 108 (FIG. 4) including at least one alloying element is formed on the duct wall 104 (FIG. 3), where the at least one alloying element can include Al, Si, Ta, Ti, Cr, or B. At 308, the duct wall 104 (FIG. 4) with the surface layer 108 (FIG. 4) is heat treated by the first heat-treatment, where the first heat-treatment is configured to infiltrate the at least one alloying element. At 310, the component 96 is heat treated in the second heat-treatment, where the second heat-treatment is configured to form precipitates. In a non-limiting example, the surface layer 108 is strengthened by infiltration and precipitation formation, and the metallic layer is left as nickel, cobalt, iron, nickel-cobalt, or nickel-cobalt-phosphorous alloy in the core or central region. Referring generally to FIGS. 2-8, it is contemplated that a second surface layer can be formed on the metallic layer 98 of the component 96. The second surface layer can be of at least one other alloying element, where the at least one other alloying element can be Al, Si, Ta, Ti, Cr, or B. The addition of a second surface layer can be followed by second heat treating of the component 96. More than one surface layer followed by a heat treating can create the desired balance of the properties for the component 96. In addition, the method of FIG. 8 can be repeated to form a component 96 with a greater thickness. That is, the repetition of the method of FIG. 8 creates a thicker component 96 with a uniform distribution of the strengthening precipitates 114.

[0053]It is further contemplated that the methods described herein, can be utilized to form functionally gradient materials. The term “functionally gradient materials”, used herein can be defined as multifunctional materials, which contain a variation in one or both of composition and microstructure for the specific purpose of controlling variations in thermal, structural, or functional properties. That is, in a non-limiting example, the specific geometry or elemental make-up of one or more surface layers 108 deposited on the metallic layer 98, allows the component 96 to have areas of differing functional properties. In another non-limiting example, differing functional properties can include the exterior surface 103 being harder than the interior surface 105.

[0054]Aspects of the present disclosure provide for a variety of benefits. In one aspect, a process including the deposition of gamma-prime forming elements such as aluminum, silicon, tantalum, or titanium within an electroformed part allows for components with additional properties from those formed merely through electroforming. For example, inclusion of aluminum or titanium can provide greater strength properties. Inclusion of elements such as chromium, boron, or silicon can provide improved corrosion and oxidation resistance. Multiple surface layers of different alloying elements can provide for thicker walled parts with high strength from the gamma-prime forming elements and corrosion and oxidation resistance from the elements such as boron or silicon.

[0055]To the extent not already described, the different features and structures of the various embodiments may be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments and is not meant to be construed that it may not be but is done for brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure.

[0056]This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

[0057]Further aspects are provided by the subject matter of the following clauses:

[0058]A method comprising forming a component by way of electrodeposition of a metallic layer over an exposed surface of a sacrificial mandrel, removing the sacrificial mandrel, forming a surface layer of at least one alloying element on the metallic layer, heat treating the component having the metallic layer and the surface layer of at least one alloying element.

[0059]The method of any preceding clause, wherein the metallic layer is one of elemental nickel, cobalt, iron, or nickel-cobalt alloy.

[0060]The method of any preceding clause, wherein the at least one alloying element is selected from a group of: aluminum, silicon, tantalum, titanium, chromium, and boron.

[0061]The method of any preceding clause, wherein the metallic layer has a thickness of 25 micrometers to 5000 micrometers.

[0062]The method of any preceding clause, wherein the surface layer has a thickness of 12.5 micrometers to 130 micrometers.

[0063]The method of any preceding clause, wherein the at least one alloying element comprises multiple alloying elements selected from the group.

[0064]The method of any preceding clause, further comprising forming a second surface layer of at least one other alloying element and another heat treating of the component.

[0065]The method of any preceding clause, wherein the metallic layer is elemental nickel and the at least one alloying element is aluminum and wherein the heat treating infiltrates the aluminum into the metallic layer and creates a strengthened precipitate of nickel-aluminide.

[0066]The method of any preceding clause, wherein the heat treating comprises a first heat-treatment wherein the at least one alloying element infiltrates the metallic layer.

[0067]The method of any preceding clause, wherein the heat treating comprises a second heat-treatment configured to form precipitates.

[0068]The method of any preceding clause, wherein the second heat-treatment is a multi-step aging process.

[0069]The method of any preceding clause, wherein the first heat-treatment is further configured to homogenize a distribution of the at least one alloying element., further comprising forming a second surface layer of at least one other alloying element and another heat treating of the component.

[0070]The method of any preceding clause, wherein forming the surface layer comprises at least one of vapor phase x-iding or pack cementation.

[0071]The method of any preceding clause, further comprising welding the metallic layer prior to forming the surface layer.

[0072]The method of any preceding clause, wherein heat treating is performed at a treatment temperature of 500° C. to 1200° C.

[0073]The method of any preceding clause, wherein the component is a duct and wherein the surface layer is formed on an exterior surface and an interior surface of the duct.

[0074]The method of any preceding clause, wherein the duct is at least one of non-linear, non-circular, or includes a variable metallic layer thickness.

[0075]A component formed from the method of any preceding clause.

[0076]The component of any preceding clause, wherein the metallic layer is elemental nickel, cobalt, iron, or a nickel-cobalt, or a nickel-cobalt-phosphorous alloy and the at least one alloying element is selected from a group of: aluminum, silicon, tantalum, titanium, chromium, and boron.