Porous metal coupon with sealed cavity for repairing component, component with that coupon, and related method

Abstract

To provide a replacement coupon for repairing a component.MEANS FOR SOLVING THE PROBLEM: A metal coupon (200) for repairing a component (202) includes an additively manufactured (AM) metal member (330) having a sealed cavity (296) in the interior of the AM metal member (330) and a porous region (300) therearound. A metal coupon system may include at least two AM metal parts (292) with each AM metal part (292) including at least a partial section of a sealed cavity therein and a porous region therearound. The AM metal parts combine to form the metal coupon including the sealed cavity in the interior thereof and the porous region therearound. The sealed cavity is hollow. The porous metal coupon with the sealed cavity provides reduced mass and allows braze material (310) to be directed on the basis of the characteristics of the porous region.SELECTED DRAWING: Figure 7A

Description

Technical Field

[0001] The present disclosure generally relates to the repair of components, and more specifically to the repair of components using a porous metal coupon having a sealed cavity.

Background Art

[0002] Industrial components sometimes need to be repaired. For example, high-temperature gas path components used to direct a working fluid for energy generation in a turbomachine may need to be repaired. High-temperature gas path components can take various shapes, such as turbine rotor blades or stationary vanes that include airfoils for directing a working fluid for energy generation. The rotor blades are coupled to the turbine rotor and act to rotate the turbine rotor, and the stationary vanes are coupled to the casing of the turbomachine and direct the working fluid towards the rotor blades.

[0003] Additive manufacturing, such as direct metal laser melting (DMLM) or selective laser melting (SLM), has emerged as a reliable manufacturing method for producing industrial components. With the advent of additive manufacturing technology, it has also become possible to replace a part of a component, such as a part of the leading or trailing edge of a turbomachine blade. For example, a part of the leading edge of a turbomachine blade can be removed to leave a notch in the blade, and a new section (referred to herein as a "coupon") can be joined to the blade at the notch. The coupon is additively manufactured to have a shape that at least generally matches the shape of the notch. This coupon can replace a worn portion of a used turbomachine blade or be added as part of a new turbomachine blade. The coupon can easily replace the internal cooling structure of the turbomachine blade or provide an additional or improved cooling structure (e.g., a cooling passage close to the wall) that was not provided in the original turbomachine blade.

[0004] However, the replacement coupon is made of the same material and has the same exterior structure as the removed part of the component. Therefore, the replacement coupon has some of the same drawbacks as the original component and / or notch, and there is no improvement in overall performance characteristics such as overall strength, stress / strain resistance, ductility, wear resistance, thermal conductivity or electrical conductivity and / or mass loss. When using one type of brazing material to bond the replacement coupon to the component, it is also impossible to improve additional performance characteristics related to the joint, such as the above-mentioned overall performance characteristics, further improvement in joint adhesion strength and reliability, and reduction of machining / blending operations required after brazing. Also, using a coupon made of substantially the same material as the removed notch makes it impossible to reduce the high material cost of the replacement coupon.

SUMMARY OF THE INVENTION

[0005] All aspects, specific examples, and features listed below can be combined in technically possible ways.

[0006] Aspects of the present disclosure provide a metal coupon system for repairing components, the metal coupon system comprising two or more additive manufacturing (AM) metal members, each AM metal member including at least a portion of a sealed cavity therein and a porous region surrounding at least a portion of the sealed cavity, and when combining two or more AM metal members, a metal coupon including a sealed cavity therein and a porous region surrounding the sealed cavity is formed, and the sealed cavity is hollow.

[0007] Another aspect of the present disclosure includes any of the above aspects, and the porous region has variable porosity having two or more partial regions with different porosities.

[0008] Another aspect of the present disclosure includes a metal coupon for repairing a component, the metal coupon including an AM metal member having a sealed cavity therein and a porous region surrounding the sealed cavity, and the sealed cavity is hollow.

[0009] Another aspect of the present disclosure includes any of the above aspects, and the porous region has a variable porosity having two or more porous partial regions with different porosities.

[0010] Another aspect of the present disclosure includes any of the above aspects, and the porous region includes an outer porous partial region adjacent to the outer surface of the AM metal member, the outer porous partial region having a higher porosity than the inner porous partial region near the sealing cavity, and the outer porous partial region is configured to receive more brazing material than the inner porous partial region.

[0011] Another aspect of the present disclosure includes any of the above aspects, the sealing cavity is defined inside the brazing material infiltration barrier, and the porous region is outside the brazing material infiltration barrier.

[0012] Another aspect of the present disclosure includes any of the above aspects, the AM metal member includes a first metal member in which a first section of the sealing cavity is defined inside, and a second metal member in which a second section of the sealing cavity is defined inside, and the first metal member and the second metal member are joined using a brazing material that infiltrates the porous region.

[0013] Another aspect of the present disclosure includes any of the above aspects, the AM metal member further includes a discharge hole that extends from the outer surface of the AM metal member to the sealing cavity and is configured to remove material from inside the sealing cavity, and further includes a sealing element inside the discharge hole to seal the discharge hole.

[0014] Another aspect of the present disclosure includes any of the above aspects, and the porosity of the porous region increases from near the sealing cavity toward the outer surface of the AM metal member.

[0015] Another aspect of the present disclosure includes any of the above aspects, and the porosity of the porous region increases in a plurality of increasing stages from near the sealing cavity toward the outer surface of the AM metal member.

[0016] Aspects of the present disclosure include components, where the component is an AM metal coupon having a body, a sealed cavity inside the additive manufacturing (AM) metal coupon, and a porous region around the sealed cavity, the sealed cavity being hollow, and a brazing material that bonds the AM metal coupon to a coupon opening of the body, the brazing material being infiltrated into the porous region.

[0017] Another aspect of the present disclosure includes any of the above aspects, where the porous region has a variable porosity having two or more porous sub-regions with different porosities.

[0018] Another aspect of the present disclosure includes any of the above aspects, where the porous region includes an outer porous sub-region adjacent to the outer surface of the AM metal member, the outer porous sub-region having a higher porosity than an inner porous sub-region near the sealed cavity, and the outer porous sub-region is configured to receive more brazing material than the inner porous sub-region.

[0019] Another aspect of the present disclosure includes any of the above aspects, where the sealed cavity is defined inside a brazing material infiltration barrier, and the porous region is outside the brazing material infiltration barrier.

[0020] Another aspect of the present disclosure includes any of the above aspects, where the AM metal coupon includes a first metal member having a first section of the sealed cavity defined therein and a second metal member having a second section of the sealed cavity defined therein, and the brazing material bonds the first metal member and the second metal member of the AM metal coupon to the opening of the body to form the sealed cavity.

[0021] Another aspect of the present disclosure includes any of the above aspects, where the AM metal coupon further includes a discharge hole extending from the outer surface of the AM metal coupon to the sealed cavity, and further includes a sealing element in the discharge hole to seal the discharge hole.

[0022] Another aspect of the present disclosure includes any of the above aspects, and the porosity of the porous region increases from near the sealing cavity toward the outer surface of the AM metal coupon.

[0023] Another aspect of the present disclosure includes any of the above aspects, and the porosity of the porous region increases in a plurality of increasing stages from near the sealing cavity toward the outer surface of the AM metal coupon.

[0024] One aspect of the present disclosure includes a method of repairing a component, the method comprising the steps of additive manufacturing a metal coupon having a sealing cavity and a porous region around the sealing cavity, disposing the metal coupon in a coupon opening of a body of the component, and infiltrating the metal coupon with a brazing material to bond the metal coupon within the coupon opening of the body together with the sealing cavity therein, wherein the brazing material infiltrates the porous region of the metal coupon and the sealing cavity is hollow.

[0025] Another aspect of the present disclosure includes any of the above aspects, and the porous region has variable porosity having two or more porous partial regions with different porosities.

[0026] Another aspect of the present disclosure includes any of the above aspects, and the metal coupon has a near-net shape of the coupon opening.

[0027] Another aspect of the present disclosure includes any of the above aspects, and additive manufacturing includes forming the porous region to include an outer porous partial region having a higher porosity than an inner porous partial region of the metal coupon near the sealing cavity adjacent to the outer surface of the metal coupon, and after infiltration, the outer porous partial region contains more brazing material inside than the inner porous partial region.

[0028] Another aspect of the present disclosure includes any of the above aspects, and additive manufacturing includes forming a venting cavity inside a brazing material infiltration barrier, and the porous region is outside the brazing material infiltration barrier.

[0029] Another aspect of the present disclosure includes any of the above aspects, and the additive manufacturing involves additive manufacturing of one or more metal members, each metal member including at least a portion of a sealing cavity and a porous region surrounding at least a portion of the sealing cavity, and the arranging step includes arranging one or more metal members in a coupon opening to form a metal coupon.

[0030] Another aspect of the present disclosure includes any of the above aspects, and the additive manufacturing includes additive manufacturing of an entire sealing cavity on a single metal coupon, the arranging step includes arranging the single metal coupon in the coupon opening, and the impregnation includes impregnating the single metal coupon.

[0031] Another aspect of the present disclosure includes any of the above aspects, and the additive manufacturing includes additive manufacturing of a single metal coupon having a discharge hole extending from an outer surface of the single metal coupon into the sealing cavity and configured to remove material from within the sealing cavity, further including removing material from within the sealing cavity using the discharge hole, and further including sealing the discharge hole with a sealing element.

[0032] Another aspect of the present disclosure includes any of the above aspects, and further includes, before the additive manufacturing, the step of forming a coupon opening in the body of the component configured to receive the metal coupon, and the step of creating a model of the coupon opening, and the additive manufacturing includes manufacturing the metal coupon such that the metal coupon has a near-net shape of the coupon opening based on the model of the coupon opening.

[0033] Combinations of two or more aspects described in this disclosure, including the aspects described in the Summary section of this invention, may also be used as embodiments not specifically described herein. That is, all the embodiments described in this application can be combined with each other.

[0034] The details of the above embodiments are described in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the detailed description of the invention, the drawings, and the claims.

Brief Description of the Drawings

[0035] Regarding the other features of the present disclosure, a better understanding can be obtained by referring to the following detailed description in conjunction with the accompanying drawings that describe various embodiments of the present disclosure.

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[0036] The drawings of the present disclosure are not necessarily to scale. The drawings merely illustrate typical aspects of the present disclosure and do not limit the technical scope of the present disclosure. In the drawings, like reference numerals represent like components among multiple drawings.

Mode for Carrying Out the Invention

[0037] First, in order to clearly explain the technical content of the present disclosure, it is necessary to select terms when referring to and describing mechanical components related to exemplary uses of turbomachinery. As much as possible, use general terms in the technical field in accordance with their ordinary meanings. Unless otherwise specified, such terms should be interpreted broadly in accordance with the context of this application and the appended claims. It will be apparent to those skilled in the art that a component is often referred to using several different or overlapping terms. In this specification, what is described as a single member may be described as consisting of multiple components in another context. Or, what is described as including multiple components in one place in this specification may be described as a single member in another place.

[0038] Furthermore, although several descriptive terms are used repeatedly in this specification, it would be useful to define them at the beginning of this section. These terms and their definitions are as follows, unless otherwise specified. As used in this specification, the terms "downstream" and "upstream" indicate directions with respect to the flow of a fluid (e.g., the flow of a working fluid through a turbine engine, or the flow of air through a combustor or a coolant through one of the component systems of a turbine). The term "downstream" corresponds to the direction in which the fluid is flowing, and the term "upstream" refers to the direction opposite to the flow (i.e., the direction from which the fluid is coming). The terms "forward" and "rearward" refer to directions that are not further specified, with "forward" indicating the front of the turbomachine or the compressor end, and "rearward" indicating the rear of the turbomachine or the turbine end.

[0039] Furthermore, as described below, several descriptive terms are used repeatedly in this specification. The terms "first", "second", and "third" are used interchangeably to distinguish one component from another and do not indicate the position or importance of individual components.

[0040] The terms used in this specification are for illustrative purposes only and do not limit the disclosure. In this specification, even if something is described in the singular, it is meant to include the plural as well, unless otherwise clear from the context. In this specification, the terms "comprising", "including", and / or "having" indicate the presence of the described features, integers, steps, operations, components, and / or parts, and do not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts, and / or groups thereof. The terms "optional" or "suitably" mean that the event described following the term may or may not occur, or the feature described following the term may or may not be present, and such descriptions include both the case where the event occurs or the feature is present and the case where the event does not occur or the feature is not present.

[0041] When a component or layer is "on", "engaged with", "connected to", "coupled to", or "attached to" another component or layer, it may be located directly on top of that other component or layer, directly engaged with, connected to, coupled to, or attached to that other component or layer, or there may be intervening components or layers. In contrast, when a component is "directly on top of", "directly engaged with", "directly connected to", or "directly coupled to" another component or layer, there are no intervening components or layers. Other terms used to describe the relationship between components (e.g., "between" and "directly between", "adjacent" and "directly adjacent", etc.) are interpreted similarly. The verb forms of "coupled" and "attached" may be used synonymously.

[0042] As described above, the present disclosure provides a metal coupon for repairing a component. The metal coupon includes an additive manufacturing (AM) metal member having a sealed cavity inside the additive manufacturing (AM) metal member and a porous region around the sealed cavity. The sealed cavity is hollow. The present disclosure encompasses a metal coupon system including two or more additive manufacturing (AM) metal members, each AM metal member including at least a section of at least a part of the sealed cavity inside thereof and a porous region around at least a section of at least a part of the sealed cavity. When two or more AM metal members are combined, a metal coupon (i.e., an AM member) including a sealed cavity inside thereof and a porous region around the sealed cavity is formed. As used herein, a "coupon" includes a component that is part of a component at the time of original manufacture or is disposed in a coupon opening of the main body of the component for repairing a part of the component (e.g., after removing a damaged portion). The component includes a main body and an additive manufacturing (AM) metal coupon having a sealed cavity inside the additive manufacturing (AM) metal coupon and a porous region around the sealed cavity. The component may include a brazing material for bonding the metal coupon to the coupon opening of the main body. The brazing material infiltrates the porous region. The sealed cavity reduces the mass of the metal coupon. Further, one or more porous regions of the metal coupon are configured to direct the flow of one or more brazing materials in a different manner so as to produce physical properties different from those previously possible (e.g., by directing more brazing material to a required location, directing the brazing material into a special shape, and / or enabling the use of two or more types of brazing materials). When used for repair, the customized metal coupon does not exhibit the same disadvantages as the original component and / or notch, and can be customized (using one or more brazing materials) to change, for example, joint adhesion strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or mass. One or more brazing materials can be used not only to bond the replacement coupon to the component, but also to improve performance characteristics related to joints such as joint adhesion strength and reliability, and to reduce the machining / blending operations required after brazing. The use of a porous metal coupon can also reduce material costs.

[0043] FIG. 1 shows a schematic diagram of an exemplary industrial machine, which can include components in accordance with the teachings of the present disclosure. In this example, the machine includes a turbomachine 100 in the form of a combustion or gas turbine (GT) system. The turbomachine 100 includes a compressor 102 and a combustor 104. The combustor 104 includes a combustion region 106 and a fuel nozzle assembly 108. The turbomachine 100 also includes a turbine assembly 110 and a common compressor / turbine shaft (i.e., rotor 112) 112. In one embodiment, the turbomachine 100 is a commercially available 7HA.03 engine from GE Vernoa. The present disclosure is not limited to any particular GT system and can be implemented with respect to other engines, including, for example, other HA, F, B, LM, GT, TM, and E class engine models from GE Vernoa, as well as engine models from other companies. The present disclosure is not limited to any particular turbomachine and can be applied to any industrial parts that use coupons during manufacturing or repair.

[0044] During operation, air flows through the compressor 102 and compressed air is supplied to the combustor 104. Specifically, the compressed air is supplied to a fuel nozzle assembly 108 built into the combustor 104. The assembly 108 is in fluid communication with the combustion region 106. The fuel nozzle assembly 108 is also in fluid communication with a fuel source (not shown in FIG. 1) and guides fuel and air into the combustion region 106. The combustor 104 ignites and burns the fuel. The combustor 104 is in fluid communication with the turbine assembly 110. The turbine assembly 110 includes a turbine 111 rotatably coupled to the rotor 112 to drive the rotor 112. The compressor 102 is also rotatably coupled to the rotor 112. In an exemplary embodiment, there are multiple combustors 104 and fuel nozzle assemblies 108.

[0045] FIG. 2 shows a cross-sectional view of an exemplary turbine assembly 110 of a turbomachine 100 (FIG. 1) that can be used in the gas turbine system of FIG. 1. The turbine 111 of the turbine assembly 110 includes a row 120 of nozzles or vanes coupled to a stationary casing 122 of the turbomachine 100 and a row 124 of blades axially adjacent thereto. The stationary vanes or nozzles 126 can be held within the turbine assembly 110 by a radially outer platform 128 and a radially inner platform 130. The row 124 of blades of the turbine assembly 110 includes rotating blades 132 coupled to a rotor 112 and rotating therewith. The rotating blade 132 may include a radially inner platform 148 (root of the blade 132) coupled to the rotor 112 (FIG. 3) and, optionally, a radially outer tip 136 (tip of the blade). As used herein, the term "component" generically refers to a structure that can use a stationary nozzle 126, a rotating blade 132, or a metal coupon including one or more porous regions according to the present disclosure.

[0046] FIGS. 3 and 4 show exemplary components to which the teachings of the present disclosure can be applied, such as high-temperature gas path components of a turbomachine. FIG. 3 shows a perspective view of a turbine rotor blade 132 of a type that can use an embodiment of the present disclosure. The turbine rotor blade 132 includes a root 140, and the rotor blade 132 is attached to the rotor 112 (FIG. 2) by the root 140. The root 140 can include a dovetail 142 configured to be mounted in a corresponding dovetail slot on the outer periphery of a rotor wheel 144 (FIG. 2) of the rotor 112 (FIG. 2). The root 140 may further include a shank 146 extending between the dovetail 142 and the platform 148, and the platform 148 is disposed at the junction of the airfoil 150 and the root 140 and defines a part of the flow path through the turbine assembly 110. The airfoil 150 is an active component of the rotor blade 132 that receives the flow of the working fluid 151 (i.e., high-temperature combustion gas) (FIG. 2) and causes rotor disk rotation. The airfoil portion 150 of the rotating blade 132 includes a concave pressure side (PS) outer wall 152 and a convex suction side (SS) outer wall 154 on the opposite side in the circumferential or transverse direction, and extends axially between a leading edge 156 and a trailing edge 158. The side outer walls 152 and 154 extend radially from the platform 148 to the outer tip 160, and the tip 60 may or may not include a tip shroud 136 (FIG. 2).

[0047] FIG. 4 is a perspective view of a stationary nozzle 126 of a type that may be used in an embodiment of the present disclosure. The stationary nozzle 126 includes an outer platform 170 by which the stationary nozzle 126 is attached to a stationary casing 122 (FIG. 2) of a turbomachine. The outer platform 170 may include any attachment configuration known currently or developed in the future for attachment to a corresponding mount of the casing. The stationary nozzle 126 may further include an inner platform 174 disposed between adjacent turbine rotor blades 132 (FIG. 3) and platforms 148 (FIG. 3). The platforms 170, 130 define respective portions of the outer and inner boundaries of a flow path through the turbine assembly 110. The airfoil portion 176 is an active component of the stationary nozzle 126 that receives the flow of the working fluid and directs the flow toward the turbine rotor blade 132 (FIG. 3). The airfoil portion 176 of the stationary nozzle 126 includes a concave pressure side (PS) outer wall 178 and a convex suction side (SS) outer wall 180 on the opposite side in the circumferential or transverse direction, and extends axially between a leading edge 182 and a trailing edge 184. The side outer walls 178 and 180 also extend radially from the platform 170 to the platform 174.

[0048] The blade 132 or the nozzle 126 may include an internal cooling structure including a coolant supply source, such as passages, conduits, and other structures for delivering the coolant to its surface for film cooling. Examples of the coolant include air from the compressor 102.

[0049] The embodiments of the present disclosure described in this application include aspects applicable to stationary nozzles 126, turbine rotor blades 132, and / or any industrial parts to which other coupons are used. FIGS. 3 and 4 also show an exemplary additive manufacturing (AM) metal coupon 200 (hereinafter, “metal coupon 200” or “AM metal coupon 200”) in a component 202. More specifically, the metal coupon 200 is within a coupon opening 204 of a body 206 of the component 202. The “coupon opening 204 of the body 206” may be any sized void within the body 206 up to and including a removed portion of the body 206 (e.g., a tip shroud). For example, the metal coupon 200 may be disposed in the coupon opening 204 at the trailing edges 158, 184 of each of the blade 132 or the nozzle 126. Alternatively, the metal coupon 200 may be disposed in the coupon opening 204 at the leading edges 156, 182 of each of the blade 132 or the nozzle 126. The metal coupon 200 may also be present at the tip of the blade 132 or the platforms 170, 174 (shown in FIG. 4) of the nozzle 126. However, the metal coupon 200 may be used in any coupon opening 204 within the body 206 of the component 202. The body 206 may be any part of the component 202 or the entire component.

[0050] The additive manufactured metal coupon 200 having a porous region of 1 or greater and a sealed cavity therein can be created using any currently known or future developed technology capable of forming the porous region. FIG. 5 shows a schematic / block diagram of an exemplary computerized metal powder additive manufacturing system 210 (hereinafter, “AM system 210”) for generating the metal coupon 200 or multiple metal coupons 200A, 200B (only one of which is shown). In the present disclosure, the formation of the metal coupon 200 using multiple melt beam sources 212, 214, 216, 218 will be described, but it will be apparent that the teachings of the present disclosure are equally applicable to the formation of multiple coupons 200A, 200B using any number of melt beam sources. In this example, the AM system 210 is arranged for direct metal laser melting (DMLM). The teachings of the present disclosure in general are equally applicable to other forms of metal powder additive manufacturing such as powder bed fusion bonding, direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser sintering (SLS), selective laser melting (SLM), and possibly other forms of additive manufacturing (i.e., those other than for metal powder applications). The coupons 200A, 200B are shown as rectangular components, but the additive manufacturing process can be readily adapted to manufacture coupons of any shape, a wide variety of different coupons, and multiple coupons on the build platform 220.

[0051] The AM system 210 generally includes a layer manufacturing control system 230 (the "control system") and an AM printer 232. As will be described below, the control system 230 executes a set of computer-executable instructions or code 234 to generate the coupon 200 using a plurality of melt beam sources 212, 214, 216, 218. In the example shown in the figure, the four melt beam sources include four lasers. However, the teachings of the present disclosure are applicable to any melt beam source, such as an electron beam, a laser, etc. The control system 230 is shown implemented in the computer 236 as computer program code. In this regard, the computer 236 is shown including a memory 238 and / or a storage system 240, a processor unit (PU) 244, an input / output (I / O) interface 246, and a bus 248. Also, the computer 236 is shown in communication with an external I / O device / resource 250. Generally, the processor unit (PU) 244 executes the computer program code 234 stored in the memory 238 and / or the storage system 240. While executing the computer program code 234, the processor unit (PU) 244 can read and write data between the memory 238, the storage system 240, the I / O device 250, and / or the AM printer 232. The bus 248 provides a communication link between each object within the computer 236, and the I / O device 250 can include any device (such as a keyboard, a pointing device, a display, etc.) that allows a user to interact with the computer 236. The computer 236 merely represents various possible combinations of hardware and software. For example, the processor unit (PU) 244 may include a single processing unit or may be distributed across one or more locations, such as one or more processing units on a client and a server. Similarly, the memory 238 and / or the storage system 240 may reside in one or more physical locations.The memory 238 and / or the storage system 240 can comprise any combination of various types of non-transitory computer-readable storage media, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), and the like. The computer 236 can include any type of computing device, such as an industrial controller, a network server, a desktop computer, a laptop, a handheld device, and the like.

[0052] As described above, the AM system 210, particularly the control system 230, executes the code 234 to generate one or more metal coupons 200. The code 234 can include, among other things, a set of computer-executable instructions 234S (also referred to herein as "code 234S") for operating the AM printer 232 and a set of computer-executable instructions 234O (also referred to herein as "code 234O") that define one or more metal coupons 200 physically generated by the AM printer 232. As described herein, the additive manufacturing process begins with a non-transitory computer-readable storage medium (e.g., the memory 238, the storage system 240, etc.) that stores the code 234. The computer-executable instructions 234S for operating the AM printer 232 can include any currently known or future-developed software code capable of operating the AM printer 232.

[0053] A set of computer-executable instructions 234O that define one or more metal coupons 200 may include an accurately defined 3D model of the coupon 200 and can be generated from well-known computer-aided design (CAD) software systems such as AutoCAD®, TurboCAD®, DesignCAD 3DMax. In this regard, the code 234O can include any file format known currently or developed in the future. Further, the code 234O representing the metal coupon 200 may be converted between different formats. For example, the code 234O may include an STL (Standard Tessellation Language) file created for a stereolithography CAD program of 3D Systems, or an American Society of Mechanical Engineers (ASME) standard additive manufacturing file (AMF), an extensible markup language (XML)-based format designed to describe any three-dimensional shape and composition to be manufactured on any AM printer by any CAD software. The code 234O representing the metal coupon 200 can also be converted to, transmitted as, received as, or stored as a set of data signals as needed. The code 234O may be configured to form boundaries and internal sections in the overlapping field region as described below, according to embodiments of the present disclosure. In any case, the code 234O may be an input to the AM system 210 and may be from a component designer, an intellectual property (IP) provider, a design company, an operator or owner of the AM system 210, or other sources. In any case, the control system 230 executes the codes 234S and 234O to divide one or more metal coupons 200 into a series of thin slices and stack them into successive layers of material using the AM printer 232.

[0054] The AM printer 232 may include a sealed processing chamber 260 to supply a controlled atmosphere for printing the metal coupon 200. The build platform 220 on which the metal coupon 200 is formed is disposed within the processing chamber 260. A number of melt beam sources 212, 214, 216, 218 are configured to melt a layer of metal powder on the build platform 220 to produce the coupon 200. Although four melt beam sources 212, 214, 216, 218 are illustrated, the teachings of the present disclosure are applicable to systems using any number (e.g., 1, 2, 3, or 5 or more) of beam sources. Each melt beam source 212, 214, 216, 218 may have a field that includes non-overlapping field regions that can exclusively melt metal powder, or may include one or more overlapping field regions where metal powder can be melted by two or more beam sources. In this regard, each melt beam source 212, 214, 216, 218 may generate a melt beam that fuses particles for each slice defined by the code 234O. For example, FIG. 5 shows that the melt beam source 212 creates a layer of the metal coupon 200 in one region using the melt beam 262, and the melt beam source 214 creates a layer of the metal coupon 200 in another region using the melt beam 262'. Each melt beam source 212, 214, 216, 218 is calibrated in any currently known or future-developed manner. That is, each melt beam source 212, 214, 216, 218 correlates the predicted position of the laser beam or electron beam relative to the build platform 220 with its actual position to provide an individual position correction (not shown) to ensure its individual accuracy. In one embodiment, each of the plurality of melt beam sources 212, 214, 216, 218 may create melt beams (e.g., 262, 262') having the same cross-sectional dimensions (e.g., shape and size during operation), output, and scanning speed.

[0055] Continuing with reference to FIG. 5, applicator (coater blade) 270 can create a thin layer of feedstock 272 spread as a blank canvas, on which each of the successive slices of the final metal coupon 200 is created. Various parts of the AM printer 232 can be moved to accommodate each new layer added, for example, after each layer, the build platform 220 can be lowered and / or the chamber 260 and / or the applicator 270 can be raised. The process can use various feedstocks in the form of fine-grained metal powders, and the stock of feedstock can be held within the chamber 260 accessible by the applicator 270. In this case, the coupon 200 can be made of metal, which can include pure metal or an alloy. In one example, the metal can be substantially any non-reactive metal powder, i.e., a powder that is non-explosive or non-conductive, such as, but not limited to, cobalt-chromium-molybdenum (CoCrMo) alloy, stainless steel, austenitic nickel-chromium-based alloy, such as nickel-chromium-molybdenum-niobium alloy (NiCrMoNb) (e.g., Inconel 625 or Inconel 718), nickel-chromium-iron-molybdenum alloy (NiCrFeMo) (e.g., Hastelloy® X available from Haynes International), or nickel-chromium-cobalt-molybdenum alloy (NiCrCoMo) (e.g., Haynes 282 available from Haynes International), etc. Other possibilities include, for example, Rene 108, CM247LC, MarM247, and other precipitation hardening (PH) nickel-based alloys, etc.

[0056] The processing chamber 260 is filled with an inert gas such as argon or nitrogen and is controlled to suppress oxygen to a minimum or completely remove it. The control system 230 is configured to control the flow of the gas mixture 274 in the processing chamber 260 from a source of the inert gas 276. In this case, the control system 230 may control the pump 280 and / or the flow valve system 282 for the inert gas to control the content of the gas mixture 274. The flow valve system 282 may include one or more computer-controllable valves, flow sensors, temperature sensors, pressure sensors, etc. that can accurately control the flow of a specific gas. The pump 280 can be provided regardless of the presence or absence of the valve system 282. When the pump 280 is omitted, the inert gas can simply enter a conduit or manifold prior to introduction into the processing chamber 260. The source of the inert gas 276 can take the form of any conventional source for the materials contained therein, such as a tank, a storage layer, or other source. Any sensors (not shown) necessary for measuring the gas mixture 274 may be provided. The gas mixture 274 can be filtered using a filter 286 in a conventional manner.

[0057] During operation, a build platform 220 with metal powder thereon is provided in the processing chamber 260, and the control system 230 controls the flow of the gas mixture 274 in the processing chamber 260 from a source of the inert gas 276. The control system 230 also controls the AM printer 232, particularly the applicator 270 and the melting beam sources 212, 214, 216, 218, to sequentially melt the layers of metal powder on the build platform 220 to produce the metal coupon 200 according to an embodiment of the present disclosure.

[0058] Although a particular AM system 210 has been described herein, the teachings of the present disclosure are not limited to a particular additive manufacturing system or method. Further, although the teachings of the present disclosure relate to an additive manufacturing metal coupon 200, the component 202 may be manufactured by any method now known or later developed, such as additive manufacturing (presumably similar to that described for the metal coupon 200), casting, or other methods. The component 202 may include any of the materials recited herein with respect to the metal coupon 200.

[0059] The metal coupon 200 includes a sealed cavity 296 within the AM metal member 330 and a porous region 300 surrounding the sealed cavity.

[0060] As used herein, "porosity" refers to the ratio of the volume of open space to the total volume of the structure of the label (such as a porous region, a metal coupon, etc.). Typically, in this regard, porosity is described as the percentage of the volume of open space relative to the total or entire volume of the structure of the label. The open space is an empty region within a solid material, which is referred to herein as "pore" 302 and may include interconnected passages within the material of the structure of the label. Thus, the "porous region" of the metal coupon 200 has a solidity of less than 100% and contains open space in the form of pores 302 and / or interconnected passages. The porous metal coupon 200 may include a solid region, but also includes one or more porous regions with a solidity of less than 100%. In this specification, the three-dimensional boundary of a porous region or sub-region for specifying the "total volume" of the porous region or sub-region is determined by the location where a change in porosity of more than 2% occurs with respect to an adjacent region or sub-region within the metal coupon 200 and / or the location where the edge of the metal coupon 200 exists. The "volume of open space" generally refers to the empty (i.e., void, interstitial, empty space, and / or space not filled with material) three-dimensional space within a region or sub-region. As used herein, "different porosities" or "porosity difference" generally means variations in various properties such as the percentage of the volume of open space relative to the total volume, the number of pores 302 within a given volume, the volume (i.e., size) of the pores 302, the shape of the pores 302, and variations in the connecting passages (referred to herein as "pore connecting passages") between pores 302 that may not be recognizable as actual discrete pores. As a non-limiting example, the pore diameter is, for example, 1.07×10 -6 ~8.58×10 - 3mm 3 (6.54×10 -11 ~5.24×10 -7It can be within the range of [cubic inches], or as another non-limiting example, the pore diameter can be within the range of 0.0127 mm to 0.254 mm (0.0005 inches to 0.01 inches). In the drawings, different porous regions or sub-regions are typically shown as continuous or in contact with each other, but they may be separated from each other (e.g., by a solid region therebetween). That is, a single metal coupon may include one or more isolated non-contact porous regions or sub-regions. The terms "region" and / or "sub-region" may be used interchangeably to indicate a change in porosity.

[0061] For example, it will be apparent that the difference in porosity is not based solely on the percentage of the volume of the void space with respect to the total volume, such as due to differences in pore shape or pore connection passages. However, when comparing the degree of difference in porosity (e.g., high or low), the difference referred to is solely with respect to volume characteristics, i.e., the difference in the percentage of the volume of the void space with respect to the total volume.

[0062] The porous metal coupon 200 can be formed to have different porous regions with different porosities (which may or may not include one or more porous sub-regions with different porosities) using the AM system 210 described herein or other metal additive manufacturing systems or methods capable of forming porous metal. With respect to the operation of the AM system 210, the melt beam sources 212, 214, 216, 218 can be programmed intermittently such that the metal is not sintered and metal powder remains instead of solid material. This process may include in the build file (i.e., code 234O) overlapping the laser field regions in various amounts and / or designing the pores 302. The less the overlap of each laser scan, the higher the porosity, and the more the laser overlap between a series of scans, the lower the porosity. To adjust the porosity, the laser spot size, scan speed, focus, and power can also be controlled. More specifically, additive manufacturing involves using an AM system 210 having one or more melt beam sources 212, 214, 216, 218 to fuse layers of metal powder and adjusting the system parameters to control the porosity of two or more porous regions. Adjusting the parameters can include one or more of adjusting the amount of overlap of the melt regions of one or more melt beams 262, 262' (FIG. 5) from the beam sources 212, 214, 216, 218, adjusting the system scan speed, or adjusting one or more of the size, focus, or power of the melt beam spot. When the unfused metal powder is removed from the metal coupon 200, the pores 302 remain along with the interconnected passages between the pores 302, and one or more porous regions are formed in the metal coupon 200. In any case, the additive manufacturing of the metal coupon 200 can be controlled to produce the desired porosity for any number, shape, and / or size of porous regions within the desired layer of one or more metal coupons 200.

[0063] Figures 6A-6D show schematic top views of sample metal coupons 200 having various porosities. The pores 302 are shown as dark void spaces in the drawings. Figure 6A shows a sample metal coupon 200 having a first porosity with a void space volume of about 40% relative to the total volume of the sample (generally having a high amount of void space and a large amount and / or large pores 302), Figure 6B shows a sample metal coupon 200 having a first porosity with a void space volume of about 30% relative to the total volume of the sample, Figure 6C shows a sample metal coupon 200 having a first porosity with a void space volume of about 20% relative to the total volume of the sample, and Figure 6D shows a sample metal coupon 200 having a first porosity with a void space volume of about 10% relative to the total volume of the sample (generally having a low amount of void space). Each porous region can have a void space volume of 2% to 50% (i.e., 2 to 50% void space and the remaining 50 to 98% solid) relative to the total volume of the porous region. In other embodiments, each porosity can be a void space volume of 10% to 40% (i.e., 10% to 40% void space and the remaining 60 to 90% solid) relative to the total volume of the porous region 300. In other embodiments, the porous region has a porosity within the range of less than 10%, less than 15%, less than 20%, less than 25%, less than 30%, less than 35%, less than 40%, less than 45%, 2% to 45%, 2% to 40%, 2% to 35%, 2% to 30%, 2% to 25%, 2% to 20%, 5% to 45%, 5% to 40%, 5% to 35%, 5% to 30%, 5% to 25%, 5% to 20%, 10% to 45%, 10% to 40%, 10% to 35%, 10% to 30%, 10% to 25%, 10% to 20%, 15% to 45%, 15% to 40%, 15% to 35%, 15% to 30%, 15% to 25%, 15% to 20%, 10% to 50%, 20% to 50%, 25% to 50%, 30% to 50%, 35% to 50% or 40% to 50%. As described herein, other ranges of porosity are also possible.

[0064] Figures 7A - 7N show diagrams of an exemplary metal coupon 200 according to an embodiment of the present disclosure. The metal coupon 200 includes a metal additive manufacturing (AM) member 330 having a sealed cavity 296 therein and a porous region 300 surrounding the sealed cavity 296 (Figures 7B - 7D, 7I - 7N). The sealed cavity 296 is hollow. That is, the sealed cavity 296 is a cavity space of sufficient size that does not include the cavity space of the pores 302 visible within the AM metal member 330, i.e., distinguishable pores. The sealed cavity 296 may have a surface profile on its inner surface and may have, for example, ribbed features (not shown) for increasing heat transfer. The metal coupon 200 can be additively manufactured in a number of formats. As will be described with respect to Figures 7B - 7J, the metal coupon 200 can be additively manufactured using a metal coupon system 290 that uses two or more AM metal members 292 that collectively form the AM metal member 330. Alternatively, as will be described with respect to Figures 7K - 7N, the metal coupon 200 and its AM metal member 330 can also be additively manufactured as a single piece member.

[0065] Regarding the metal coupon system 290, Figure 7A shows a perspective view of the metal member 292 (hereinafter "member") of the metal coupon system 290, Figure 7B shows the member 292 of the metal coupon system 290 connected to the AM metal member 330 of the metal coupon 200, and Figure 7C shows a cross-sectional view taken along the arrow 7C - 7C of Figure 7B. As shown in Figures 7A - 7C, the metal coupon system 290 includes two or more additive manufacturing (AM) metal members 292A, 292B, and each AM metal member 292A - B includes at least a sealed cavity section 294A - B of the sealed cavity 296 (Figures 7B - 7C) therein (eventually). Each member 292 includes a porous region 300 surrounding at least a portion of the section 294 of the sealed cavity 296.

[0066] The sealing cavity 296 can be collectively defined by a member 292 having a sealing cavity section 294. In the example shown in the figure, the metal coupon system 290 includes two members 292A and 292B, each including a (substantially) half section 294A and 294B of the sealing cavity 296. However, any number of members 292 can be used, each having a portion of the sealing cavity 296 that, when the members 292 are joined together, can collectively form the sealing cavity 296. FIG. 7I shows another example including three members 292A - C each including a sealing cavity section 294A - C, respectively. For example, as shown in FIGS. 7B - 7C and 7I, the members 292 are configured such that when combined, they form the metal coupon 200, i.e., its AM metal member 330, together with the internal sealing cavity 296 and the porous region 300 surrounding the sealing cavity 296. When two members 292A - B are used, the AM metal member 330 includes a first metal member 292A with the first section 294A of the sealing cavity 296 defined therein and a second metal member 292B with the second section 294B of the sealing cavity 296 defined therein. The members 292 may include a desired structure (e.g., an adhesive, a fitting connector 354 (FIG. 7A), a clamp, etc.) for properly aligning or temporarily clamping them before brazing. As will be described later, the first metal member 292A and the second metal member 292B are joined using a brazing material 310 that infiltrates the porous region 300.

[0067] The sealing cavity 296 can be defined in the AM metal member 330 in a number of ways. In one embodiment, the sealing cavity 296 is defined inside the brazing material infiltration barrier 304. The brazing material penetration barrier 304 (hereinafter "barrier 304") may include a layer of (low) porosity material (e.g., molten metal powder), and the brazing material 310 (Figs. 8E - 8G, Figs. 9A - 9D) used to bond the metal coupon 200 to the coupon opening 204 of the main body 206 of the part 202 does not infiltrate through the barrier 304. Thus, the barrier 304 has a low enough porosity to act as a shield for the flow of the brazing material and an enclosing layer around the sealing cavity 296. The barrier 304 may be a relatively thin layer, for example, less than 0.5 mm. The porosity of the barrier 304 prevents the infiltration of the brazing material 310 into the sealing cavity 296 and can be varied according to the material of the metal coupon 200 and the material of the brazing material 310. That is, the barrier 304 allows some infiltration of the brazing material 310 but does not allow the brazing material 310 to pass through the barrier and enter the sealing cavity 296. Although not essential, the barrier 304 may be 100% solid, i.e., the void space may be 0%. Since the porous region 300 is outside the barrier 304, the brazing material 310 directed to infiltrate the porous region 300 infiltrates until it reaches the barrier 304. The barrier 304 defines the sealing cavity 296 regardless of its shape, in other words, the barrier 304 has at least the same internal shape.

[0068] In an alternative embodiment, as shown in Fig. 7J, if the porous region 300 prevents the brazing material 310 from entering the sealing cavity section 294, the barrier 304 can be omitted. For example, if a flow path can be provided that is too long for the brazing material 310 to reach the sealing cavity section 294 - B, the barrier 304 is not required. This arrangement may require control of the brazing process, such as the supply amount, duration, pressure, temperature, etc. of the brazing material, to achieve the desired limited infiltration of the brazing material 310.

[0069] In FIGS. 7A-7D, the sealing cavity 296 is shown as having a cubic shape with a square or rectangular cross-section. However, the sealing cavity 296 can have any shape that can be formed using additive manufacturing, either as a single sealing cavity or as any of the sealing cavity sections. FIGS. 7E-7H show perspective views of non-limiting examples of the shape of the sealing cavity 296, such as, for example, a cube with a pointed top (FIG. 7E), an elliptical cross-section elongated in the height H direction (FIG. 7F), a cylindrical shape with a circular cross-section overall (FIG. 7G). The sealing cavity 296 can have a desired dimension that fits within the dimensions of the AM metal member 330. In FIG. 7B, the sealing cavity 296 has a substantially equal width W, height H, and length L, although they may be different. In FIGS. 7E-7G, the length L is shown in various dimensions (through the drawing). In the example of FIG. 7H, the sealing cavity 296 is spherical. In the cross-sectional view of FIG. 7I, the sealing cavity 296 has a triangular cross-section.

[0070] As shown in FIGS. 3, 4, 8C-8G, 9A-9D and further described herein, the brazing material 310 infiltrated into the porous region 300 joins the member 292 and joins the metal coupon 200 to the coupon opening 204 of the body 206 of the component 202. The brazing material 310 (and the barrier 304, if provided) places the AM metal member 292 in the coupon opening 204 and, when joined there with the brazing material 310, seals the sealing cavity 296. For illustration purposes, FIGS. 7B-7D and 7I show the seam 332 (dashed line) between the AM metal members 292 filled with the brazing material 310. Note that the seam 332 may not be visible with the metal coupon 200 of the component 202.

[0071] In FIGS. 7B - 7C, the porous region 300 includes a single uniform porosity outside the barrier 304. FIG. 7D shows a cross - sectional view of a metal coupon 200 and a metal coupon system 290 similar to FIG. 7C. In certain embodiments, for example, as shown in FIGS. 7D and 7I - 7L, the porous region 300 may include a variable - porosity region 312. The variable - porosity region 312 may include two or more porous sub - regions 314 with different porosities. The variable - porosity region 312 surrounds the barrier 304 (when provided) and encloses the sealing cavity 296. As shown in FIGS. 7D, 7I - 7L, the porosity of the porous region 300 may increase or decrease (or both increase and decrease) from near the sealing cavity 296 (e.g., within 0.5 mm) or adjacent thereto towards the outer surface 306 of the AM metal member 330. The change in porosity in the variable - porosity region 312 may be gradual, step - wise (as indicated by the sub - regions 314) or in some other incremental fashion. For example, FIG. 7J shows an embodiment in which all of the porous region 300 includes a variable - porosity region 312 where the porosity gradually changes (e.g., increases or decreases) from the sealing cavity 296 to the outer surface 306 of the metal coupon 200. Regarding step - wise changes, as shown in FIGS. 7D, 7I, and 7L, the porosity of the porous region 300 may increase step - wise from near the sealing cavity 296 towards the outer surface 306 of the AM metal member 330 (see the stepped porous sub - regions 314). FIG. 7D shows five different porous sub - regions 314, FIG. 7I shows two different porous sub - regions 314, and FIG. 7L shows three different porous sub - regions 314. Any number of stepped sub - regions 314 may be used.

[0072] The different porosities of the variable porous region 312 and / or the partial region 314 differ from each other with respect to one or more of the properties of the percentage of the cavity space volume with respect to the total volume, pore shape, pore size, number of pores, or pore connectivity. Each porous region 300 or porous part region 314 can have any porosity, as described above. The different porosities enable control of the uptake of the brazing material 310 into the metal coupon 200 (i.e., by capillary action). Illustrated with respect to FIG. 7I, the porous region 300 includes an outer porous part region 314A adjacent to the outer surface 306 of the AM metal member 330, and this outer porous part region 314A has a higher porosity than the inner porous part region 314B near the sealing cavity 296. Thus, the outer porous part region 314A is configured to receive more brazing material 310 than the inner porous part region 314B. Thus, the uptake of the brazing material 310 is minimized at or near the barrier 304 and increases as it moves away from the sealing cavity 296. In another embodiment, as shown by the dashed line in FIG. 7I, the variable porous region 312 can include an intermediate variable porous part region 313 in which the porosity (dashed line) gradually changes between the outer porous part region 314A and the inner porous part region 314B. As described above, the change in porosity can be gradual, stepwise, or incremental. In any case, the outer porous part region 314A is configured to receive more brazing material 310 than the inner porous part region 314B. Thus, the uptake of the brazing material 310 is minimized at or near the sealing cavity 296 and increases as it moves away from the sealing cavity 296. The variable porous part region 313 can take up the brazing material 310 at an uptake level between the inner porous part region 314B and the outer porous part region 314B.

[0073] FIG. 7K shows a perspective view, and FIG. 7L shows a cross-sectional view taken along the line 7L-7L of FIG. 7K of the metal coupon 200 according to another embodiment of the present disclosure. Similarly, FIG. 7M shows a perspective view of the metal coupon 200 according to another embodiment of the present disclosure, and FIG. 7N shows a cross-sectional view taken along the line 7N-7N in FIG. 7M. In these embodiments, the metal coupon 200 includes an AM metal member 330 having a sealed cavity 296 and a porous region 300 around the sealed cavity 296 inside the AM metal member 330. As described above, the sealed cavity 296 is hollow, that is, a cavity space of sufficient size that does not include a cavity space or distinguishable pores 302. In FIGS. 7K to 7N, the porous region 300 can take any of the forms described herein, for example, a uniform porosity throughout, a variable porous region 312 where the porosity increases and / or decreases, a porous region 312 having a porous partial region 314 (three locations in FIG. 7L), and the like.

[0074] As described in connection with FIGS. 7B - 7J, the metal coupon 200 may include a member 292 (i.e., the metal coupon system 290) having a sealing cavity section 294, which are joined together using a brazing material 310 to form a sealing cavity 296. However, in FIGS. 7K - 7N, the AM metal member 330 of the metal coupon 200 is additively manufactured as a single piece. In FIGS. 7K - 7L, the metal coupon 200 further includes a discharge hole 340 that extends from the sealing cavity 296 to the outer surface 306 of the metal coupon 200 (i.e., the AM metal member 330). The discharge hole 340 is configured, for example, to remove a material 362 (FIG. 8B) from the (intended) sealing cavity 296 after additive manufacturing. The material 362 (FIG. 8B) to be removed may include materials used in the formation of the sealing cavity 296, such as materials or structures that support the sintered metal powder layer during additive manufacturing. The material 362 (FIG. 8B) may include, for example, unmelted metal powder or other structures that can be removed through the discharge hole 340. Other structures include sacrificial supports that can support the metal layers of the AM metal member 330. When using metal powder, the discharge hole 340 can be formed by leaving a layer of unmelted metal powder in the area where the discharge hole 340 is to be located, which can be removed from the discharge hole 340 (e.g., by shaking or applying a vacuum (see FIG. 8B) or a gas flow to the metal coupon 200). After removing the material 362 (FIG. 8B), the discharge hole 340 may be sealed. For example, as shown in FIGS. 7K - 7L, the metal coupon 200 may further include a sealing element 342 in the discharge hole 340 for sealing the discharge hole 340. The sealing element 342 may include any currently known or future - developed structure for sealing the coupon opening, such as, but not limited to, a complete filling of the discharge hole 340 or a limited application of the brazing material 310 that is insufficient for filling the sealing cavity 296, a plug brazed in place, or spot welding. The discharge hole 340 can be located anywhere within the metal coupon 200 and can have any path (other than linearity as shown) as long as the material 362 (FIG. 8B) can be removed from the sealing cavity 296 and the discharge hole 340.Note that the position of the discharge hole 340 may be finally arranged on the outer surface 306 of the metal coupon 200 facing the coupon opening 204 so as not to come to the outer surface of the metal coupon 200 in the component 202 in the operating state.

[0075] Referring to FIGS. 7M to 7N, the metal coupon 200 includes an AM metal member 330 having a sealing cavity 296 and a porous region 300 around the sealing cavity 296 inside the AM metal member 330. As described above, the sealing cavity 296 is hollow, that is, a cavity space of sufficient size that does not include a cavity space or distinguishable pores 302. In FIGS. 7M to 7N, the AM metal member 330 of the metal coupon 200 is laminated and formed as an integral member. The metal coupon 200 includes the sealing cavity 296 inside thereof, but does not include a discharge hole as shown in FIGS. 7K to 7L. The sealing cavity 296 can be formed by any currently known or future-developed method that can form a sealing cavity in the AM metal structure 330 without a discharge hole (for example, probably with some metal powder remaining inside).

[0076] The metal coupon 200 shown in FIGS. 7A to 7N has a shape configured to be arranged in the coupon opening 204 of the trailing edge 158 or 184 of the blade 132 or the nozzle 126, respectively, as shown in FIGS. 3 and 4. However, the metal coupon 200 can be used in any coupon opening 204 of any part of the body 206 of any component 202 and can have a variety of shapes adapted to the coupon opening 204.

[0077] Next, embodiments of the method according to the present disclosure will be described with reference to FIGS. 3, 4, 5, 7A to 7N, and 8A to 8F. The method may include repairing the component 202. FIGS. 8A to 8F show perspective views of the method according to embodiments of the present disclosure.

[0078] FIG. 8A shows the creation of a coupon opening 204 in the body 206 of the component 202. The coupon opening 204 will ultimately house a metal coupon 200 (a plurality of members 292 forming the metal coupon 200 or a single-piece metal coupon 200). The coupon opening 204 may have any shape. In certain applications, the coupon opening 204 is created by removing a damaged portion of the body 206 of the component 202, but the coupon opening 204 may also be something that is originally present in the component 202 (e.g., something in a location that is difficult to manufacture along with the rest of the component 202). In the non-limiting example shown in the figure, the coupon opening 204 is at the trailing edge 184 of the nozzle 126. FIG. 8A also shows the creation of a model of the coupon opening 204. Model creation may include scanning a digital representation of the coupon opening 204 relative to the body 206 of the component 202 using any 3D scanner (not shown, see arrow) that is currently known or developed in the future. The process of scanning and modeling components is well known in the art and will not be described in further detail so as to focus on the characteristic aspects of the present disclosure.

[0079] FIGS. 5 and 7A - 7N show a laminated metal coupon 200. The metal coupon 200 can be laminated as a plurality of members or as a single piece. As shown in FIGS. 5 and 7A, lamination may include laminating one or more metal members 292. Each metal member 292 includes at least a section 294 of a (predetermined) sealing cavity 296 and a porous region 300 surrounding the section of the sealing cavity 296. As shown in FIGS. 5, 7K, and 7M, lamination may include laminating the entire sealing cavity 296 into a single-piece metal coupon 200.

[0080] FIG. 7A shows the porous region 300 around the sections 294A - B of the sealing cavity 296 of the members 292A - B, and FIGS. 7K and 7M show the porous region 300 around the complete sealing cavity 296. As shown in FIGS. 7A - 7C, the additive manufacturing may include forming at least a portion of the section 294 of the sealing cavity 296 within the barrier 304, and the porous region 300 is outside the barrier 304. FIGS. 7A - 7C show a formed metal coupon 200 having a single porosity (not solid), for example, FIG. 7D shows the formation of a metal coupon 200 having a variable porous region 312 with two or more porous partial regions 314 having different porosities. The variable porous region 312 may include a porosity that gradually changes between the sealing cavity 296 and the outer surface 306 of the metal coupon 200. For example, as shown in FIG. 7I, the additive manufacturing may include forming the porous region 300 such that the outer porous partial region 306 near the outer surface 306 of the metal coupon 200 has a higher porosity than the inner porous partial region 314B near at least a portion of the section 294 of the sealing cavity 296 of the metal coupon 200. Other porosity arrangements of the porous region 300 described herein may also be used in the member 292.

[0081] FIGS. 7K - 7L show the additive manufacturing of a single metal coupon 200 having a discharge hole 340 configured to extend from the sealing cavity 296 to the outer surface 306 of the single metal coupon 200 and to remove material from within the sealing cavity 296. FIGS. 7M - 7N show additive manufacturing of the entire sealing cavity 296 with a single metal coupon 200.

[0082] Additive manufacturing includes manufacturing the porous metal coupon 200 or multiple members 292 thereof (or dense or solid regions) by any AM process described herein. Additive manufacturing may include manufacturing the metal coupon 200 having a near-net shape of the coupon opening 204 such that it substantially matches the profile (e.g., shape, dimensions, etc.) of the coupon opening 204 or is based on a model of the coupon opening 204. That is, additive manufacturing may include forming the members 292 that collectively form the metal coupon 200 or a single-piece metal coupon 200. As used herein, "near-net shape" means that after manufacturing the metal coupon 200 (multiple members 292 that form the AM metal member 330 or a single-piece AM metal member 330), when the metal coupon is placed in the coupon opening 204, the outer shape is very close to one or more surfaces of the body 206 that require repair (i.e., the portion of the body where the metal coupon 200 needs to be joined to the coupon opening 204). For example, the product requires minimal finishing methods such as machining or grinding. Using the porous region 300 in the metal coupon 200 allows it to accommodate larger variations in the joint gap dimensions compared to a solid coupon with a narrow gap for the brazing material. This is because the porous region improves the brazing material's gripping and retention even with a large gap. Figures 8B - 8H show the metal coupon 200 being additively manufactured in the shape of, for example, the embodiments of Figures 7B, 7K, and 7M, but it can take any form described herein.

[0083] In an embodiment of the present disclosure, the porosity of the second porous region 300 or the partial region 314 of the metal coupon 200 is controlled or customized, and then, during the brazing process of coupling the metal coupon 200 to the coupon opening 204 (Figs. 3-4, Figs. 8E-8F) of the body 206 (Figs. 3-4, Figs. 8E-8F) of the component 202 (Figs. 3-4, Figs. 9A-9D), the flow of the brazing material 310 inside is controlled. Each porous region 300 or partial region 314 can be customized with respect to any of the above-described properties that affect porosity. Additive manufacturing also includes forming a sealed cavity 296 inside the barrier 304 together with the porous region 300 outside the barrier 304. As described above, providing the barrier 304 can prevent the infiltration of the brazing material 310. Further, the shape and / or position of the porous region 300 or partial region 314 can be arranged to direct the brazing material as desired. For example, in Figs. 7A-7B, the entire metal coupon 200 includes a uniform porous region 300, and the brazing material 310 becomes uniformly distributed therein. In contrast, for example, in Fig. 7D, the metal coupon 200 includes an outermost porous partial region 314A near the edge 308 of the metal coupon 200 that couples to the coupon opening 204 (Figs. 3-4), and another porous partial region 314B with different porosity near the sealed cavity 296 away from the edge 308. Thus, the brazing material 310 is distributed differently in each porous partial region 314, causing different physical properties in the metal coupon 200 in these different regions. More specifically, any number of different porous partial regions can be used to cause one or more different physical properties, such as joint adhesion strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or mass, in the component 202 including the metal coupon 200. As a non-limiting example that can be considered, the metal coupon 200 may increase the porosity in a certain porous partial region 314 to increase the amount of brazing material guided by capillary action compared to other solid regions of the metal coupon 200, and control one or more physical properties of the component 202.In another embodiment, the metal coupon 200 may have a reduced porosity in a certain porous partial region 314, reducing the wicking material guided by capillary action compared to other solid regions of the metal coupon 200, and controlling one or more physical properties of the component 202. In another embodiment, the metal coupon 200 may include two or more porous partial regions 314 that collectively constitute the entire metal coupon 200. Any arrangement of the porous partial regions 314 can cause the desired wicking material flow and infiltration.

[0084] In certain embodiments, additive manufacturing may include forming various improvements to the component 202, for example, including structures that did not previously exist in the component 202. The component 202 may be the original component that requires improvement, or alternatively, a component that includes a removed or damaged component. For example, as shown in FIG. 7B, additive manufacturing may optionally include forming a cooling passage 350 in the metal coupon 200. The cooling passage 350 may extend within the metal coupon 200 in any manner (e.g., as a serpentine path) and may penetrate the outer surface 306 of the metal coupon 200. In another example (not shown), additive manufacturing may optionally include forming one or more support and / or cooling structures 360 (e.g., pins / fins) (possibly together with an internal cooling passage (not shown)) within the metal coupon 200. Any suitable internal structural modification can be made to the metal coupon 200. Post-additive manufacturing finishing operations (e.g., polishing to a smooth surface) known in the art or developed in the future may be optionally performed on the metal coupon 200. Preferably, however, the teachings of the present disclosure eliminate the need for specific finishing steps (e.g., but not limited to, peening, heat treatment, and hot isostatic pressing (HIP)) of the metal coupon 200 in the component 202.

[0085] Figure 8B shows an optional step when the material 362 to be removed before brazing material infiltration is included in the (planned) sealing cavity 296. In this situation, the method may further include removing the material 362 from within the sealing cavity 296 using the discharge hole 340. The material 362 can be removed using any means (e.g., but not limited to, a vacuum system 360, etc.) for removing unfused metal powder from the sealing cavity 296. FIGS. 7K - 7L show the discharge hole 340 sealed with a sealing element 342. As described above, the sealing element 342 may include any structure and / or material currently known or developed in the future for sealing an opening, for example, but not limited to, limited application of brazing material 310 insufficient to reach the sealing cavity 296, a plug brazed in place, or spot welding.

[0086] FIGS. 8C and 8D show the step of placing the metal coupon 200 in the coupon opening 204 of the body 206 of the component 202. The placement of the metal coupon 200 in the coupon opening 204 of the body 206 can be performed using any method currently known or developed in the future (e.g., manual pushing in of a slip fitting). When using the member 292, the placement includes placing two or more metal members 292 in the coupon opening 204 such that the metal coupon 200 is collectively obtained. When the entire metal coupon 200 is integrally formed, the placement includes placing a single metal coupon 200 in the coupon opening 204. If necessary, the plurality of members 292 or the single metal coupon 200 of the metal coupon 200 can be held in place using a desired method (e.g., adhesive, nickel - chromium tack welding, ball tack, resistance welding, fusion tack welding, male - female connectors (FIG. 7A), clamps, etc.).

[0087] Figures 8E - 8F show the process of infiltrating the metal coupon 200 with the brazing material 310 to join the metal coupon 200 (coupon member 292 or single - piece metal coupon) to the coupon opening 204 of the body 206 together with the sealing cavity 296 formed therein, i.e., the brazing process. When using the single - piece metal coupon 200, infiltration includes infiltrating the single - piece metal coupon and joining it to the coupon opening 204 of the body 206 together with the sealing cavity 296 formed therein, i.e., the brazing process. When using a metal coupon 200 composed of multiple members, the members 292 are also joined by infiltration. The brazing material 310 may include any brazing composition known currently or developed in the future (e.g., but not limited to, GE (Alstom) B1P, Amdry™ D15, DF4B, or BRB, etc.), and a part of its composition is shown in the following table.

[0088]

Table 1

[0089] Infiltration can include any brazing process known currently or developed in the future (e.g., the use of a vacuum brazing system, an induction brazing system, and / or an inert gas atmosphere heating system and related techniques). In one non - limiting example, brazing may include, for example, coating (Figure 8D) and heating (Figure 8E) of the brazing material 310, and causing it to flow into and around the metal coupon 200 by capillary action.

[0090] By infiltration, the brazing material 310 is injected into the porous region 300 of the metal coupon 200, and a sealing cavity 296 is formed. The infiltration may inject the brazing material 310 into the single metal coupon 200 or the member 292 forming the multi-part metal coupon 200. The brazing material 310 infiltrates the porous region 300 around the sealing cavity 296 and seals the seam 332 (Figs. 7B - 7D, Figs. 7I - 7J) where two or more members 292 are used. As described above, the sealing cavity 296 is hollow. The infiltration of the brazing material 310 is based on at least the characteristics of one or more porosities of the porous region 300. For example, as shown in Fig. 7I, the infiltration may include moving the brazing material 310 through the porous region 300 for infiltration. The porosity of the porous region 300 defines how the brazing material 310 flows. For example, as shown in Fig. 7I, the infiltration moves the brazing material 310 through the outer porous partial region 314A for infiltration based on the characteristics of the porosity (the first porosity) of the outer porous partial region 314A, and also moves the brazing material 310 through the second outer porous partial region 314B for infiltration based on the characteristics of the porosity (the second porosity) of the second outer porous partial region 314B. As shown in Fig. 7D, when the variable porous region 312 exists together with two or more porous partial regions 314 with different porosities, the brazing material 310 moves through the variable porous region 312 and infiltrates based on the characteristics (e.g., porosity gradient, stepped porosity) of the variable porous partial region 312. As shown in Fig. 7I, when the variable porous region 313 includes the inner and outer porous partial regions 314A - B and is between them, the infiltration may move and infiltrate the brazing material 310 through the outer porous partial region 314A based on the characteristics of the first porosity of the outer porous partial region 314A, move and infiltrate through the variable porous region 312 between the partial regions 314A - B based on the characteristics (e.g., porosity gradient, stepped porosity, etc.) of the variable porous region, and move and infiltrate through the inner porous partial region 314B based on the characteristics of the second porosity of the inner porous partial region 314B. When the barrier 304 exists, it prevents the brazing material 310 from entering the sealing cavity 296.When the barrier 304 is present, the brazing process may limit the infiltration of the brazing material 310 and control it so that it does not reach the sealing cavity 296. In this case, as shown in FIG. 7J, the sealing cavity 296 is sealed by a brazing material that approaches but does not penetrate into the sealing cavity 296, and a part of the porous region 300 without brazing material remains around the sealing cavity 296.

[0091] The selection of different porosities in the porous region 300 results in different flows and infiltrations of the brazing material 310. As a result of the brazing process, the porous region 300 or sub-region 314 with different porosities, together with the brazing material 310 inside it, results in one or more different physical properties. In an example shown in FIG. 7D, the porosity of the first outer porous sub-region 314A is higher (i.e., lower density) than the porosity of the second inner porous sub-region 314B. In this case, infiltration includes infiltrating more brazing material 310 into the first outer porous sub-region 314A than into the second inner porous sub-region 314B. Depending on the amount of brazing material 310 used, among other factors, the difference in porosity enables customization of one or more physical properties of the component 202 (such as joint adhesion strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or mass). Also, the shape and size of the sealing cavity 296 enable customization with respect to mass (e.g., by removing unnecessary material). Furthermore, the multiple flow paths of the brazing material 310 using the porous region 300 can reduce the risk of insufficient filling and / or voids along the brazed joint compared to conventional brazing processes for filling narrow gaps and due to the strict manufacturing tolerances required for brazing narrow gaps.

[0092] In one embodiment, different brazing materials 310 can be used on different portions of the metal coupon 200 to further customize the bonding of the metal coupon 200 in the component 202. For example, referring to FIG. 9C, a first brazing material 310A can be used on the first metal member or side surface 326 of the component 202, and another brazing material 310B different from the first brazing material 310A can be used on a different member or side surface 328 of the component 202. As an example, referring to FIGS. 3, 4, and 9A-9D, the first metal member or side surface 326 of the component 202 may be the first (concave positive pressure) side outer walls 152, 178 of the airfoil portions 150, 176, and the second member or side surface 328 of the component 202 may be the second (convex negative pressure) side outer walls 154, 180 of the airfoil portions 150, 176. By utilizing different brazing materials 310A, 310B on different members or side surfaces 326, 328, in addition to different porous regions 300, it is possible to customize according to the expected environment of the component 202 at those positions. Thus, there are a very large number of variations in the brazing material and / or the porous region / partial region, enabling it to handle various difficult-to-repair situations.

[0093] Other embodiments of the method according to the present disclosure include simply forming one or more metal coupons 200 for repairing the component 202. In this case, as shown in FIG. 8A, the method includes creating a model of the coupon opening 204 in the body 206 of the component 202 and additive manufacturing the metal coupon 200 as described herein.

[0094] Any post-manufacturing finishing process known currently or developed in the future (e.g., peening, heat treatment, hot isostatic pressing (HIP)) may be appropriately performed on the metal coupon 200. FIG. 8F illustrates any finishing step of the component 202, such as peening and machining for seamlessly transitioning the surface of the component 202 at the location where the metal coupon 200 is added. However, the teachings of the present disclosure may eliminate the need for other finishing processes commonly used to address residual stresses present in the material after additive manufacturing, such as peening, heat treatment, hot isostatic pressing (HIP).

[0095] Figures 3, 4, and 9A - 9D illustrate embodiments of component 202 according to embodiments of the present disclosure. Figures 9A - 9D show enlarged cross - sectional views of metal coupon 200 having a sealing cavity 296 within coupon opening 204 of body 206 of component 202. Figure 9A shows component 202 having metal coupon 200 with a single porous region 300, Figure 9B shows component 202 having metal coupon 200 with two or more porous partial regions 314A, 314B, Figure 9C shows component 202 having metal coupon 200 with two or more porous partial regions 314A, 314B and one or more different brazing materials 310A, 310B. Figure 9D shows component 202 having metal coupon 200 with discharge hole 340 sealed to sealing cavity 296. The specific arrangement of porous region 300 in Figures 7A - 7N is shown in Figures 9A - 9D, but any embodiment of metal coupon 200 described in this application can be used for component 202.

[0096] Referring to Figures 9A - 9D, component 202 includes body 206. As described herein, body 206 can have any form for a particular industrial application in which component 202 is used. In the example used herein, body 206 is for turbine rotating blade 132 (Figure 3) or turbine stationary nozzle 126 (Figure 4). Metal coupon 200 is shown on airfoils 150, 176 of blade 132 and nozzle 126 in Figures 3 and 4, but metal coupon 200 can be present in any part of body 206 of component 202. Component 202 also includes an additive manufacturing (AM) metal coupon 200 having a sealing cavity 296 and a surrounding porous region 300 therein. Sealing cavity 296 is hollow as described above. Material 310 brazes metal coupon 200 to coupon opening 204 of body 206 and infiltrates porous region 300. Component 202 may also include a sealing cavity 296 defined within a brazing material infiltration barrier 304. Porous region 300 is outside of barrier 304.

[0097] As described herein, the metal coupon 200 can be constructed as a plurality of members 292 (FIG. 7A) as appropriate. As shown by the dashed lines in FIGS. 9A - C, the metal coupon 200 may include a first metal member 292A in which a first section 294A of the sealing cavity 296 is defined therein, and a second metal member 292B in which a second section 294B of the sealing cavity 296 is defined therein. The brazing material 310 bonds the first metal part 292A and the second metal part 292B of the metal coupon 200 to the coupon opening 204 of the body 206 to form the sealing cavity 296. The metal coupon 200 shown in FIG. 9D further includes a discharge hole 340 that extends from the sealing cavity 296 to the outer surface 306 of the metal coupon 200 (when using the AM metal member 330, single metal coupon 200), and the discharge hole 340 is configured to remove the material 362 (FIG. 8B) from within the sealing cavity 296. The sealing element 342 is coupled to the discharge hole 340 to seal the discharge hole.

[0098] As shown in FIG. 9A, the brazing material 310 includes a first section 370 impregnated into the first outer porous region 314A based on at least the characteristics of the first porosity of the outer porous portion region 314A. As shown in FIG. 9B, the metal coupon 200 further includes a second section 372 impregnated into a second inner porous portion region 314B having a second porosity different from the first porosity. The first porosity may differ from the second porosity in one or more respects such as the percentage of void space volume relative to the total volume, pore shape, pore size, number of pores, and / or pore connectivity. The “characteristics” of the porosity indicate that the porosity can result in various impregnation characteristics such as brazing material volume, pattern within the porosity, crystallization, etc. However, as will be apparent in the art, other factors can also affect the impregnation characteristics (such as the type of brazing material) as well as the characteristics of the brazing process (temperature, pressure, position of the component 202 and / or format and arrangement of the metal coupon 200, etc.). The body 206 may have a third porosity different from both the first porosity and the second porosity. For example, the body 206 may have a third porosity that is denser than either the first porosity or the second porosity, and may be, for example, 100% solid. Further, the barrier 304 may have different porosities as described herein. For example, the barrier 304 may have the same third porosity as the body 206, or may have a porosity that can prevent the brazing material 310 from passing through. Optionally, the metal coupon 200 may include variable porous regions 312, 313 together with two or more porous portion regions 314 (the square portion enclosed by the dashed line in FIG. 9B for convenience) between the first outer porous portion region 314A and the second inner porous portion region 314B (and possibly including a part thereof). The variable porous region 312 may have a porosity that gradually (e.g., stepwise or incrementally) changes between the first porosity and the second porosity. For example, as shown in FIG. 7D, the porosity of the porous region 300 may increase in a distinct incremental stepwise manner (by the porous portion region 314) from the sealing cavity 296 towards the outer surface 306 of the metal coupon 200.As described herein, in certain examples, the porosity of the porous region 300 may increase from the seal cavity 296 towards the outer surface 306 of the metal coupon 200, and much of the brazing material 310 is in the more outer porous sub-region (e.g., 314A (FIG. 7I) of the metal coupon 200 of the component 202).

[0099] In FIG. 9C, the brazing material 310B includes a second section 372 that infiltrates into the second outer porous portion region 314B based on at least the characteristics of the second porosity. The first outer porous portion region 314A and the second inner porous portion region 314B, together with the brazing material 310 within them, have one or more different physical properties. The porosity can be customized to select their physical properties as long as the porosity can affect their physical properties. In one example, the first porosity of the first outer porous portion region 314A may be higher (i.e., lower in density) than the second porosity of the second inner porous portion region 314B, and the first outer porous portion region 314A contains more brazing material 310 inside than the second inner porous portion region 314B. As shown in FIG. 7I, the porous region 300 may include an outer porous portion region 314A adjacent to the outer surface 306 of the metal coupon 200, and has a higher porosity than the inner porous portion region 314B near the sealing cavity 296 (e.g., within 0.5 mm). In this case, the outer porous portion region 314A contains more brazing material 310 inside than the inner porous portion region 314B. In another example, the first outer porous portion region 314A shown in FIG. 9B is at least partially at the edge 308 of the metal coupon 200 configured to be coupled to the body 206. Also, the second outer porous portion region 314B may be adjacent to the first outer porous portion region 314A. Alternatively, the second outer porous portion region 314B may be at least (another) part of the edge 308 of the metal coupon 200 and may be adjacent to the first outer porous portion region 314A in some cases. This arrangement shown in FIG. 9B is beneficial for enhancing the joint adhesion strength of the metal coupon 200 within the coupon opening 204 of the body 206 due to the increased amount of brazing material 310 disposed near the brazed joint 374, or for reducing oxidation at the brazed joint 374 or increasing the thermal conductivity of the brazed joint 374. Any of the physical properties described herein can also be customized based on various porosities and / or various brazing materials.As described above, depending on the brazing material 310 used, different porosities may enable customization of one or more physical properties of the component 202, such as joint adhesion strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or mass. As described above, the metal coupon 200 may have a near-net shape of the coupon opening 204 of the body 206 of the component 202.

[0100] In the present application, specific positions are exemplified for various porous regions 300 and / or partial regions 314, but the various porous regions or partial regions may be arranged in any manner to provide various brazing material infiltration characteristics and various physical properties of the component 202.

[0101] Embodiments of the present disclosure may include a turbomachine 100 including a turbine assembly 110 shown in FIGS. 1-2, as well as one or more components 202 described herein. The component 202 may take the form of a turbine stationary nozzle 126, a turbine rotating blade 132, or other components of the turbomachine 100. The metal coupon 200 can be used for new components or components that require repair.

[0102] The present disclosure provides various technical and commercial advantages, examples of which are described. With respect to the repair or improvement of components, in additive manufacturing, custom-fit shaped metal coupons can be cost-effectively created, and only the damaged material needs to be removed. Porous regions or partial regions can increase the proportion of the base metal alloy in a specific region (e.g., >60%), and improved physical properties may be obtained compared to, for example, pre-sintered preforms. Porous regions or partial regions can also result in a brazing / fusion particle matrix (e.g., superalloy metal base material) with enhanced brazing filler compared to metal particles surrounded by brazing filler as in the conventional way. Multiple flow paths for the brazing filler using multiple porous regions or partial regions can reduce the risk of insufficient filling and / or voids along the brazed joint compared to the conventional brazing process of filling narrow gaps. The porous region or its partial region can be formed with various porosities / densities throughout the metal coupon, enabling highly customized brazing filler flow. The porous region or its partial region can also accommodate large variations in joint void dimensions compared to a solid coupon during machining with a narrow brazing filler gap. With respect to repairs where the base material powder for the metal coupon is expensive, the overall coupon / repair material cost can be controlled by carefully designing its porosity (selection of the ratio of brazing filler to coupon metal) and sizing the encapsulation cavity. Similarly, the overall mass and structural strength of the metal coupon can be controlled by controlling the dimensions of the encapsulation cavity.

[0103] The approximating language, as used herein and in the claims, is applied to modify a quantity that represents a quantity that can vary within an acceptable range that does not cause a change in the basic function to which the quantity relates. Thus, values modified by terms such as "about," "substantially," and "essentially" are not limited to their exact numerical values. In some instances, the approximating language corresponds to the precision of the instrument for measuring the value. In some cases, the approximating language corresponds to the precision of the instrument for measuring the value. In this specification and the claims, ranges of numerical limitations are combinable and / or interchangeable with each other. Such ranges, unless otherwise apparent from the context, identify and subsume any sub-ranges included within the range. The "about" used with a particular value of a range applies to the upper and lower limits and may indicate ±10% of the recited numerical value, except when it depends on the precision of the instrument for measuring the value.

[0104] In the following claims, corresponding structures, materials, acts, and equivalents of the components specified by functional recitation include any structure, material, or act that functions in combination with other components specifically recited in the claims. The description of the present disclosure is for purposes of illustration and explanation and is neither exhaustive nor limiting to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The embodiments of the present disclosure are selected and described so as to best explain the principles of the present disclosure and its practical applications and to enable those skilled in the art to understand the present disclosure for various embodiments and various modifications suitable for a particular application.

Description of Reference Numerals

[0105] 200 Metal coupon 202 Component 210 Laminated formed metal member 296 Sealing cavity 300 Porous region 304 Brazing material infiltration barrier

Claims

1. A metal coupon (200) for repairing a part (202), the metal coupon (200) comprising: Two or more additively manufactured (AM) metal members (292), each of which includes at least a portion of a sealing cavity (296) therein and a porous region (300) surrounding at least a portion of the sealing cavity (296) when the two or more additively manufactured metal members (292) are combined together, a metal coupon is formed having a sealed cavity (296) therein and a porous region (300) surrounding the sealed cavity (296), the sealed cavity (296) being hollow.

2. The metal coupon (200) of claim 1, wherein the porous region (300) has variable porosity having two or more subregions of differing porosity.

3. A metal coupon (200) for repairing a part (202), the metal coupon (200) comprising: Additively manufactured (AM) metal part (330) having a sealed cavity (296) therein and a porous region (300) surrounding the sealed cavity (296) and wherein the sealing cavity (296) is hollow.

4. The metal coupon (200) of claim 3, wherein the porous region (300) has variable porosity having two or more subregions of differing porosity.

5. 4. The metal coupon (200) of claim 3, wherein the porous region (300) includes an outer porous portion region (314A) adjacent an outer surface (306) of the additively manufactured metal part (330) having a higher porosity than an inner porous portion region (314B) near the sealing cavity (296), the outer porous portion region (314A) being configured to accept more brazing material (310) than the inner porous portion region (314B).

6. The metal coupon (200) of claim 3, wherein the sealed cavity (296) is defined inside a braze-infiltrated barrier (304) and the porous region (300) is outside the braze-infiltrated barrier (304).

7. 4. The metal coupon (200) of claim 3, wherein the additively manufactured metal member (330) comprises a first metal member (292A) having a first section (294A) of the sealing cavity (296) defined therein, and a second metal member (292B) having a second section (294B) of the sealing cavity (296) defined therein, the first metal member (292A) and the second metal member (292B) being bonded together using a braze material (310) that infiltrates a porous region (300).

8. 4. The metal coupon (200) of claim 3, wherein the additively manufactured metal part (330) further includes an exhaust hole (340) extending from an outer surface (306) of the additively manufactured metal part (330) to the sealed cavity (296) and configured to remove material from within the sealed cavity (296), and further includes a sealing element (342) within the exhaust hole (340) for sealing the exhaust hole (340).

9. 4. The metal coupon (200) of claim 3, wherein the porosity of the porous region (300) increases from a vicinity of the sealed cavity (296) toward an outer surface (306) of the additively manufactured metal part (330).

10. 4. The metal coupon (200) of claim 3, wherein the porosity of the porous region (300) increases in multiple incremental steps from a vicinity of the sealed cavity (296) toward an outer surface (306) of the additively manufactured metal part (330).

11. A part (202), the part (202) comprising: A main body (206); an additively manufactured (AM) metal coupon (200) having a sealed cavity (296) therein and a porous region (300) surrounding the sealed cavity (296), the sealed cavity (296) being hollow; a braze material (310) for bonding the additively manufactured metal coupon (200) to the coupon opening (204) of the body (206), the braze material (310) infiltrating the porous region (300); A part (202) comprising:

12. The component (202) of claim 11, wherein the porous region (300) has variable porosity having two or more subregions of differing porosity.

13. 12. The part (202) of claim 11, wherein the porous region (300) includes an outer porous portion region (314A) adjacent an outer surface (306) of the additively manufactured metal part (330), the outer porous portion region (314A) having a higher porosity than an inner porous portion region (314B) near the sealing cavity (296), the outer porous portion region (314A) including more brazing material (310) than the inner porous portion region (314B).

14. The component (202) of claim 11, wherein the sealed cavity (296) is defined inside a braze-infiltrated barrier (304) and the porous region (300) is outside the braze-infiltrated barrier (304).

15. 12. The part (202) of claim 11, wherein the additively manufactured metal part (330) includes a first metal part (292A) having a first section (294A) of the sealing cavity (296) defined therein and a second metal part (292B) having a second section (294B) of the sealing cavity (296) defined therein, and a braze material (310) bonds the first metal part (292A) and the second metal part (292B) within the coupon opening (204) of the body (206) to form the sealing cavity (296).

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