Method for using metal sample block having porous region for component

Abstract

The present disclosure relates to a method of using a metal specimen block having a porous region for a component. A method of coupling a metal sample block (200) to a component (202) may include additive manufacturing a metal sample block (200) having a first porous region (300A) having a first porosity and a second porous region (300B) having a second porosity different from the first porosity. A metal specimen block (200) is positioned in a specimen block opening (204) in a body (206) of the component (202). The metallic sample block (200) may be infiltrated with a braze material (310) to couple the metallic sample block (200) in a sample block opening (204) in the body (206). The one or more brazing materials (310) are infiltrated into at least one of the first porous region (300A) and the second porous region (300B) based at least on a characteristic of the first porosity and at least on a characteristic of the second porosity. The cured braze material (310) includes different segments having different physical properties based on different porosities and / or different braze materials.

Description

Technical Field

[0001] The present disclosure relates generally to component repair, and more particularly to component repair using metal coupons having porous areas. Background Art

[0002] Industrial components sometimes need repair. For example, hot gas path components used in turbines to direct working fluid to create energy may need repair. Hot gas path components can take many forms, such as turbine rotating blades or stationary vanes including airfoils that direct working fluid to create energy. The rotating blades are coupled to the turbine rotor and are used to turn the turbine rotor, and the stationary vanes are coupled to the casing of the turbine to direct the working fluid toward the rotating blades.

[0003] Additive manufacturing, such as direct metal laser melting (DMLM) or selective laser melting (SLM), has become a reliable manufacturing method for manufacturing industrial components. The advent of additive manufacturing technology also provides the ability to replace sections of components, such as a portion of the leading edge or trailing edge of a turbine nozzle. For example, a portion of the leading edge of a turbine nozzle can be removed, leaving a cutout in the nozzle, and a new section (referred to herein as a "coupon") can be connected in the cutout. The coupon is additively manufactured to have a shape that at least roughly matches the shape of the cutout. The coupon can replace a section of a used turbine nozzle or be added as part of a new turbine nozzle.

[0004] The present invention relates to the method for replacing the coupon block. However, the replacement coupon block is made of the material and external structure identical with the removed part of the parts. Therefore, the replacement coupon block can suffer from some shortcomings in the shortcomings identical with the original parts and / or the incision, and does not improve the general performance characteristics, such as the coupon strength, oxidation resistance, cyclic fatigue, stress resistance / strain resistance, ductility, wear resistance, thermal conductivity or electrical conductivity and / or the quality reduced. Use a single brazing material to replace the coupon block and connect it to the parts, which has prevented the improvement of the general performance characteristics listed above and the additional performance characteristics related to the joint, such as increasing the joint adhesive bonding strength and reliability, and reducing the required brazing post-processing / mixing. Use the coupon block substantially identical with the incision removed and do not allow the high material cost of the replacement coupon block to be reduced. Summary of the invention

[0005] All aspects, examples and features mentioned below can be combined in any technically possible way.

[0006] One aspect of the present disclosure provides a component comprising: a body; an additively manufactured (AM) metal coupon having a first porous region, the first porous region having a first porosity, the first porosity being an open space volume of 2% to 50% of a total volume of the first porous region; and a brazing material coupling the AM metal coupon in a coupon opening in the body, the brazing material comprising a first segment that infiltrates into the first porous region based at least on a property of the first porosity.

[0007] Another aspect of the present disclosure includes any of the foregoing aspects, and the AM metal coupon further includes a second porous region having a second porosity different from the first porosity, and wherein the braze material includes a second segment that infiltrates into the second porous region based at least on a characteristic of the second porosity.

[0008] Another aspect of the disclosure includes any of the foregoing aspects, and the AM metal coupon includes a variable porosity region between the first porous region and the second porous region.

[0009] Another aspect of the disclosure includes any of the foregoing aspects, and the body has a third porosity different from both the first porosity and the second porosity.

[0010] Another aspect of the disclosure includes any of the foregoing aspects, and the first porosity is an open space volume of 10% to 40% of the total volume of the first porous region.

[0011] Another aspect of the disclosure includes any of the foregoing aspects, and the AM metal coupon has a near net shape of the coupon opening in the body of the component.

[0012] Another aspect of the disclosure includes any of the foregoing aspects, the AM metal coupon comprising a cooling channel in the AM metal coupon.

[0013] Another aspect of the present disclosure includes a component comprising: a body; an additively manufactured (AM) metal coupon comprising a first porous region having a first porosity and a second porous region having a second porosity different from the first porosity; and a brazing material coupling the AM metal coupon in a coupon opening in the body, the brazing material infiltrating into at least one of the first porous region and the second porous region based at least on a property of the first porosity and at least on a property of the second porosity.

[0014] Another aspect of the disclosure includes any of the foregoing aspects, and the body has a third porosity different from both the first porosity and the second porosity.

[0015] Another aspect of the disclosure includes any of the foregoing aspects, and the AM metal coupon includes a variable porosity region between and including the first porous region and the second porous region.

[0016] Another aspect of the disclosure includes any of the foregoing aspects, and the first porosity is different from the second porosity in at least one of the following characteristics: percentage of open space volume to total volume, pore shape, pore size, number of pores, and pore connecting channels.

[0017] Another aspect of the disclosure includes any of the foregoing aspects, and the first porosity is higher than the second porosity and the first porous region includes more brazing material in the first porous region than the second porous region.

[0018] Another aspect of the present disclosure includes any of the aforementioned aspects, and at least one different physical property is selected from the group consisting of: joint adhesive bond strength, coupon strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, cyclic fatigue, thermal conductivity, electrical conductivity, surface roughness, hardness, and mass.

[0019] Another aspect of the present disclosure includes any of the preceding aspects and further includes a cooling channel defined in the AM metal coupon.

[0020] Another aspect of the disclosure includes any of the foregoing aspects, and the first porous region is located in at least a portion of an edge of the metal coupon configured for joining to the body, and the second porous region is adjacent to the at least a portion of the first porous region.

[0021] Another aspect of the present disclosure includes any of the aforementioned aspects, and the first porosity and the second porosity are respectively 2% to 50% of the open space volume of the total volume of the first porous region and the second porous region.

[0022] Another aspect of the present disclosure includes any of the aforementioned aspects, and the first porosity and the second porosity are open space volumes of 10% to 40% of the total volume of the first porous region and the second porous region, respectively.

[0023] One aspect of the present disclosure includes a gas turbine comprising: a turbine assembly; and at least one component, the at least one component comprising: a body; an additively manufactured (AM) metal sample block, the additively manufactured (AM) metal sample block comprising a first porous region having a first porosity and a second porous region having a second porosity different from the first porosity; and a brazing material, the brazing material coupling the AM metal sample block in a sample block opening in the body, the brazing material infiltrating into at least one of the first porous region and the second porous region based at least on characteristics of the first porosity and at least on characteristics of the second porosity.

[0024] Another aspect of the disclosure includes any of the foregoing aspects, and the AM metal coupon includes a variable porosity region between and including the first porous region and the second porous region.

[0025] Another aspect of the disclosure includes any of the foregoing aspects, and the first porosity is higher than the second porosity and the first porous region includes more brazing material in the first porous region than the second porous region.

[0026] One aspect of the present disclosure includes a method of joining a metal coupon in a component, the method comprising: additively manufacturing a metal coupon having a first porous region and a second porous region, the first porous region having a first porosity and the second porous region having a second porosity different from the first porosity; positioning the metal coupon in a coupon opening in a body of the component; and infiltrating the metal coupon with a brazing material to join the metal coupon in the coupon opening in the body, wherein the infiltrating includes infiltrating the brazing material into at least one of the first porous region and the second porous region based at least on a characteristic of the first porosity and at least on a characteristic of the second porosity.

[0027] Another aspect of the present disclosure includes any of the preceding aspects, and wherein the first porous region and the second porous region containing the braze material have at least one different physical property.

[0028] Another aspect of the disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a metal coupon having a variable porosity region between and including a first porous region and a second porous region.

[0029] Another aspect of the present disclosure includes any of the foregoing aspects, and infiltrating the metal coupon with a brazing material includes passing the brazing material through and infiltrating the first porous region based on a characteristic of a first porosity, passing through and infiltrating the variable porosity region based on a characteristic of the variable porosity region, and passing through and infiltrating the second porous region based on a characteristic of a second porosity.

[0030] Another aspect of the disclosure includes any of the foregoing aspects, and the first porosity is different from the second porosity in at least one of the following characteristics: percentage of open space volume to total volume, pore shape, pore size, number of pores, and pore connecting channels.

[0031] Another aspect of the disclosure includes any of the preceding aspects, and the first porosity is higher than the second porosity, and wherein infiltrating includes infiltrating the first porous region with more braze material than the second porous region.

[0032] Another aspect of the present disclosure includes any of the aforementioned aspects, and at least one different physical property is selected from the group consisting of: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness and mass.

[0033] Another aspect of the disclosure includes any of the preceding aspects, and the additive manufacturing includes forming a cooling channel in the metal coupon.

[0034] Another aspect of the present disclosure includes any of the preceding aspects, and the infiltrating includes using vacuum brazing, induction brazing, or inert gas atmosphere heating.

[0035] Another aspect of the present disclosure includes any of the foregoing aspects, and further includes, prior to additive manufacturing: forming a coupon opening in the body configured to receive the metal coupon; and forming a model of the coupon opening, wherein additive manufacturing includes manufacturing the metal coupon based on the model of the coupon opening.

[0036] Another aspect of the disclosure includes any of the preceding aspects, and the additive manufacturing includes manufacturing the metal coupon to a near net shape of the coupon opening based on the model of the coupon opening.

[0037] One aspect of the present disclosure relates to a method of forming a metal coupon for coupling a metal coupon in a component, the method comprising: forming a model of a coupon opening in a body of the component; and additively manufacturing (AM) the metal coupon based on the model of the coupon opening, the metal coupon comprising at least a first porous region having a first porosity and a second porous region having a second porosity different from the first porosity, whereby after the metal coupon is coupled in the coupon opening using a brazing material, the different first porosities and the second porosities produce different physical properties.

[0038] Another aspect of the disclosure includes any of the preceding aspects, and the additive manufacturing includes manufacturing the metal coupon to a near net shape of the coupon opening based on the model of the coupon opening.

[0039] Two or more aspects described in this disclosure (including those described in this summary) can be combined to form a specific implementation not specifically described herein. That is, all embodiments described herein can be combined with each other.

[0040] The details of one or more implementations are set forth in the drawings and description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the present disclosure taken in conjunction with the accompanying drawings which depict various embodiments of the present disclosure, wherein:

[0042] Figure 1 shows a schematic diagram of an illustrative industrial machine in the form of a gas turbine system and including components according to embodiments of the present disclosure;

[0043] Figure 2 Shows that Figure 1 A cross-sectional view of an exemplary gas turbine assembly for use with a gas turbine system in and including components according to an embodiment of the present disclosure;

[0044] Figure 3 shows a perspective view of a component in the form of a turbine rotating blade including a metal coupon according to an embodiment of the present disclosure;

[0045] Figure 4 shows a perspective view of a component in the form of a turbine nozzle including a metal coupon according to an embodiment of the present disclosure;

[0046] Figure 5 A schematic block diagram of an exemplary additive manufacturing system for additive manufacturing of a metal coupon according to an embodiment of the present disclosure is shown;

[0047] FIG. 6A to FIG. 6D shows a top view of a sample metal coupon including porous regions having different porosities according to an embodiment of the present disclosure;

[0048] 7A to 7E shows a perspective view of a metal coupon according to various embodiments of the present disclosure;

[0049] FIG. 8A to FIG. 8F shows a perspective view of a method according to various embodiments of the present disclosure; and

[0050] 9A to 9D An enlarged cross-sectional view of a metal coupon in a coupon opening in a body of a component is shown in accordance with an embodiment of the present disclosure.

[0051] It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered to limit the scope of the present disclosure. In the drawings, like numbers represent like elements between drawings. DETAILED DESCRIPTION

[0052] First, in order to clearly describe the present disclosure, it will be necessary to select certain terms when referring to and describing relevant machine components within an exemplary application of a turbine. In doing so, common industry terms will be used and adopted in a manner consistent with their accepted meanings, if possible. Unless otherwise stated, such terms should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. A person of ordinary skill in the art will understand that several different or overlapping terms may be used to refer to a particular component. An object that may be described herein as a single part may include multiple components and be referenced in another context as consisting of multiple components. Alternatively, an object that may be described herein as comprising multiple components may be referred to elsewhere as a single part.

[0053] In addition, several descriptive terms may be used regularly throughout this document, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise indicated, these terms, along with their definitions, are as follows. As used herein, "downstream" and "upstream" are terms that indicate the direction relative to the flow of a fluid, such as a working fluid through a turbine, or, for example, an air flow through a combustor or a coolant through one of the component systems of a turbine. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite to the flow. In the absence of any additional particularity, the terms "front" and "rear" refer to directions, with "front" referring to the front end or compressor end of a turbine, and "rear" referring to the rear end or turbine end of a turbine.

[0054] In addition, several descriptive terms may be used regularly herein, as described below. The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0055] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "one", "a kind of" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in the specification, the terms "include" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. "Optional" or "optionally" means that the event described subsequently may or may not occur, or the feature described subsequently may or may not exist, and the description includes the instance of the event occurring (or feature existing) and the instance of the event not occurring (or feature not existing).

[0056] Where an element or layer is referred to as being "on another element or layer," "engaged to another element or layer," "connected to another element or layer," "coupled to another element or layer," or "mounted to another element or layer," it may be directly on, engaged to, connected to, coupled to, or mounted to another element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to," there are no intervening elements or layers. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The verb forms "couple" and "mount" are used interchangeably herein.

[0057] As noted above, the present disclosure provides a component comprising: a body; and an additively manufactured (AM) metal coupon having a first porous region having a first porosity, the first porosity being an open space volume of 2% to 50% of the total volume of the first porous region. As used herein, a "coupon" may include any portion configured to be positioned in a coupon opening in the body of a component as part of an original manufacture or repair, i.e., it is an insertable portion. In certain embodiments, the AM metal coupon may include a first porous region having a first porosity and a second porous region having a second porosity different from the first porosity. A method of coupling a metal coupon to a component may include additively manufacturing the metal coupon as noted and positioning the metal coupon in a coupon opening in the body of the component. The metal coupon may be infiltrated with a brazing material to couple the metal coupon to the coupon opening in the body. The brazing material infiltrates into at least one of the first porous region and the second porous region based at least on the characteristics of the first porosity and (if provided) based at least on the characteristics of the second porosity. Thus, the component also includes a brazing material that connects the AM metal coupon in the coupon opening in the body. The brazing material includes a first section that infiltrates into the first porous region based at least on the characteristics of the first porosity, and may include a second section that infiltrates into the second porous region based at least on the characteristics of the second porosity. One or more porosities of the AM metal coupon are configured to direct the flow of one or more brazing materials in different ways to form physical properties different from previously possible physical properties, such as by directing more brazing material when needed, directing the brazing material into a special shape, and / or allowing the use of more than one brazing material. In the case of repair, the customized AM metal coupons do not suffer from the same disadvantages as the original parts and / or cuts, and can be customized (using brazing materials) to change, for example: joint adhesive bond strength, coupon strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, cyclic fatigue, thermal conductivity, electrical conductivity, surface roughness, hardness and quality. The repair is stronger than traditional narrow gap brazing methods, does not require specific post-repair finishing, and also provides improved physical properties compared to current technologies (such as pre-sintered preforms (PSP)). One or more brazing materials can be used to connect the replacement coupon to the component to also improve performance characteristics related to the joint, such as joint adhesive bond strength and reliability, and reduce the required post-braze processing / mixing. The use of porous AM coupons can also reduce material costs, for example by using less expensive substrates for metal coupons.

[0058] Figure 1A schematic diagram of an exemplary industrial machine that may include components according to the teachings of the present disclosure is shown. In this example, the machine includes a turbine 100 in the form of a combustion or gas turbine (GT) system. The turbine 100 includes a compressor 102 and a combustor 104. The combustor 104 includes a combustion region 106 and a fuel nozzle assembly 108. The turbine 100 also includes a turbine assembly 110 and a common compressor / turbine shaft or rotor 112. In one embodiment, the turbine 100 is a 7HA.03 engine commercially available from GE Vernova. The present disclosure is not limited to any particular GT system and may be implemented in conjunction with other engines, including, for example, other HA, F, B, LM, GT, TM and E-class engine models of GE Vernova and engine models of other companies. In addition, the present disclosure is not limited to any particular turbine and may be applicable to, for example, steam turbines, jet engines, compressors, turbofans, etc. In addition, the present disclosure is not limited to any particular turbine component and may be applicable to any industrial component that uses a sample block during manufacturing or repair.

[0059] In operation, air flows through the compressor 102 and the compressed air is supplied to the combustor 104. Specifically, the compressed air is supplied to the fuel nozzle assembly 108, which is integral with the combustor 104. The assembly 108 is in fluid communication with the combustion zone 106. The fuel nozzle assembly 108 is also connected to a fuel source ( Figure 1 The compressor 102 is fluidly connected to the rotor 112 (not shown) and delivers fuel and air to the combustion area 106. The burner 104 is ignited and the fuel is burned. The burner 104 is fluidly connected to the turbine assembly 110 so that the gas flow thermal energy is converted into mechanical rotational energy. The turbine assembly 110 includes a turbine 111, which is rotatably coupled to the rotor 112 and drives the rotor. The compressor 102 is also rotatably coupled to the rotor 112. In the exemplary embodiment, there are multiple burners and fuel nozzle assemblies 108.

[0060] Figure 2 A turbine 100 ( Figure 1 ) is a cross-sectional view of an exemplary turbine assembly 110, which may be Figure 1 The turbine 111 of the turbine assembly 110 includes a row of nozzles or buckets 120 coupled to a stationary housing 122 of the turbine 100 and an axially adjacent row 124 of rotating blades 132. The stationary buckets or nozzles 126 may be retained in the turbine assembly 110 by radially outer platforms 128 and radially inner platforms 130. The row 124 of blades in the turbine assembly 110 includes rotating blades 132 that are coupled to the rotor 112 and rotate with the rotor. The rotating blades 132 may include radially inward platforms 148 coupled to the rotor 112 (at the root of the blades, Figure 3), and optionally includes a radially outward tip shroud 136 (at the tip of the blade). As used herein, the term "component" may collectively refer to the fixed nozzle 126, the rotating blade 132, or any other structure in which a metal coupon including a porous region according to the present disclosure may be employed.

[0061] Figure 3 and Figure 4 Illustrative components of a turbomachine in which the teachings of the present disclosure may be employed, such as hot gas path components, are shown. Figure 3 1 shows a perspective view of a turbine rotating blade 132 of the type in which embodiments of the present disclosure may be employed. The turbine rotating blade 132 includes a root 140 by which the rotating blade 132 is attached to the rotor 112 ( Figure 2 ). The root portion 140 may include a dovetail 142 configured to be mounted on the rotor 112 ( Figure 2 ) of the rotor wheel 144 ( Figure 2 ) in a corresponding dovetail groove in the periphery of the blade 132. The root 140 may also include a shank 146 extending between the dovetail 142 and a platform 148, which is disposed at the junction of the airfoil 150 and the root 140 and defines a portion of the inner side boundary of the flow path through the turbine assembly 110. It should be understood that the airfoil 150 is a moving part of the rotating blade 132 that intercepts the working fluid 151 ( Figure 2 ) (i.e., hot combustion gases) and causes the rotor disk to rotate. It will be seen that the airfoil 150 of the rotating blade 132 includes a concave pressure side (PS) outer wall 152 and a circumferentially or laterally opposite convex suction side (SS) outer wall 154 extending axially between opposite leading edges 156 and trailing edges 158, respectively. The side outer walls 152 and 154 also extend in the radial direction from the platform 148 to the outboard tip 160, which may or may not include the tip shroud 136 ( Figure 2 ).

[0062] Figure 4 1 shows a perspective view of a stationary nozzle 126 of the type in which embodiments of the present disclosure may be employed. The stationary nozzle 126 includes an outer platform 170 by which the stationary nozzle 126 is attached to the stationary casing 122 ( Figure 2 The outer platform 170 may include any now known or later developed mounting configuration for mounting in a corresponding mounting member in the casing. The fixed nozzle 126 may also include a nozzle for positioning between the adjacent turbine rotating blades 132 ( Figure 3 ) and Platform 148( Figure 3) between the inner platform 174. The platforms 170, 174 define respective portions of the outboard and inboard boundaries of the flow path through the turbine assembly 110. It should be understood that the airfoil 176 is a movable component of the fixed nozzle 126 that intercepts the flow of the working fluid and directs the flow toward the turbine rotating blades 132 ( Figure 3 ) guide. It can be seen that the airfoil 176 of the fixed nozzle 126 includes a concave pressure side (PS) outer wall 178 and a circumferentially or laterally opposite convex suction side (SS) outer wall 180, which extend axially between opposite leading edges 182 and trailing edges 184, respectively. The side outer walls 178 and 180 also extend in the radial direction from the platform 170 to the platform 174.

[0063] It should be appreciated that the bucket 132 or nozzle 126 may include internal cooling structures including a coolant source such as channels, ducts, and other structures that deliver coolant to its surface for film cooling. The coolant may include, for example, air from the compressor 102 .

[0064] Embodiments of the present disclosure described herein may include aspects applicable to stationary nozzles 126 , turbine rotating blades 132 , and / or any other industrial component employing a coupon. Figure 3 and Figure 4 Also shown is an illustrative additively manufactured (AM) metal coupon 200 (hereinafter referred to simply as "metal coupon 200" or "AM metal coupon 200") in the component 202. More specifically, the metal coupon 200 may be positioned in a coupon opening 204 in the body 206 of the component 202. The "coupon opening 204 in the body 206" may be a void of any size in the body 206 up to and including a removed section of the body 206 (e.g., a tip shroud). For example, the metal coupon 200 may be positioned in a coupon opening 204 in the trailing edge 158, 184 of the blade 132 or the nozzle 126, respectively. Alternatively, the metal coupon 200 may be positioned in a coupon opening 204 in the leading edge 156, 182 of the blade 132 or the nozzle 126, respectively. The metal coupon 200 may also be positioned at any tip (not shown) of the blade 132 or the platform 170 of the nozzle 126 (at Figure 4 ), 174. However, it should be emphasized that the metal coupon 200 can be used in any coupon opening 204 in the body 206 of the component 202. The body 206 can be any part or all of the component 202.

[0065] The additively manufactured metal coupon 200 including one or more porous regions therein may be additively manufactured using any now known or later developed technique capable of forming a porous region. Figure 5A schematic / block diagram of an exemplary computerized metal powder additive manufacturing system 210 (hereinafter referred to as "AM system 210") for generating a metal coupon 200 or a plurality of metal coupons 200A, 200B is shown, wherein only a single layer is shown. The teachings of the present disclosure will be described with respect to building the metal coupon 200 using a plurality of melt beam sources 212, 214, 216, 218, but it should be emphasized and will be readily appreciated that the teachings of the present disclosure are equally applicable to building a plurality of 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). It should be understood that the general teachings of the present disclosure are equally applicable to other forms of metal powder additive manufacturing, such as, but not limited to, powder bed melting, 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., in addition to metal powder applications). Coupons 200A, 200B are illustrated as rectangular elements; however, it should be understood that the additive manufacturing method can be readily adapted to fabricate coupons of any shape, a wide variety of different coupons, and a large number of coupons on build platform 220 .

[0066] The AM system 210 generally includes an additive manufacturing control system 230 ("control system") and an AM printer 232. As will be described, the control system 230 executes a computer executable instruction set or code 234 to generate a sample block 200 using multiple melting beam sources 212, 214, 216, 218. In the example shown, the four melting beam sources may include four lasers. However, the teachings of the present disclosure are applicable to any melting beam source, such as an electron beam, a laser, etc. The control system 230 is shown as being implemented as a computer program code on a computer 236. To this extent, the computer 236 is shown as 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. In addition, the computer 236 is shown as communicating with an external I / O device / resource 250. In general, the processor unit (PU) 244 executes the computer program code 234 stored in the memory 238 and / or the storage system 240. When executing computer program code 234, processor unit (PU) 244 can read and / or write data to / from memory 238, storage system 240, I / O device 250 and / or AM printer 232. Bus 248 provides a communication link between each of the components in computer 236, and I / O device 250 can include any device (such as keyboard, pointing device, display, etc.) that enables a user to interact with computer 236. Computer 236 only represents various possible combinations of hardware and software. For example, processor unit (PU) 244 can include a single processing unit or one or more processing units distributed across one or more locations (such as on a client and a server). Similarly, memory 238 and / or storage system 240 can reside at one or more physical locations. The memory 238 and / or storage system 240 may include 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), etc. The computer 236 may include any type of computing device, such as an industrial controller, a network server, a desktop computer, a laptop computer, a handheld device, etc.

[0067] As noted, the AM system 210, and in particular the control system 230, executes code 234 to generate the metal coupon 200. The code 234 may include, among other things, a computer executable instruction set 234S for operating the AM printer 232 (also referred to herein as "code 234S"), and a computer executable instruction set 234O (also referred to herein as "code 234O") that defines the metal coupon 200 to be physically generated by the AM printer 232. As described herein, the additive manufacturing method begins with a non-transitory computer-readable storage medium (e.g., memory 238, storage system 240, etc.) storing the code 234. The computer executable instruction set 234S for operating the AM printer 232 may include any now known or later developed software code capable of operating the AM printer 232.

[0068] The computer executable instruction set 2340 defining the metal coupon 200 may include a precisely defined 3D model of the coupon and may be executed by a variety of well-known computer-aided design (CAD) software systems such as DesignCAD 3D Max, etc.). In this regard, the code 234O may include any file format now known or later developed. In addition, the code 234O representing the metal coupon 200 can be converted between different formats. For example, the code 234O may include a standard tessellation language (STL) file created for a 3D system's stereolithography CAD program or an additive manufacturing file (AMF) as an American Society of Mechanical Engineers (ASME) standard, which is an extensible markup language (XML)-based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be manufactured on any AM printer. The code 234O representing the metal coupon 200 can also be converted into a set of data signals as needed, and transmitted, received, converted into code, stored, etc. as a set of data signals. The code 234O can be configured according to an embodiment of the present disclosure to allow boundaries and internal segments to be formed in overlapping field areas, as will be described. In any case, code 234O may be an input to AM system 210 and may come from a part designer, an intellectual property (IP) provider, a design company, an operator or owner of AM system 210, or from another source. In any case, control system 230 executes code 234S and 234O to separate metal coupon 200 into a series of thin slices that are assembled in successive layers of material using AM printer 232.

[0069] The AM printer 232 may include a process chamber 260 that is sealed to provide a controlled atmosphere for printing of the metal coupon 200. A build platform 220 on which one or more metal coupons 200 are built is positioned within the process chamber 260. A plurality of melting beam sources 212, 214, 216, 218 are configured to melt a layer of metal powder on the build platform 220 to generate the coupon 200. Although four melting beam sources 212, 214, 216, 218 are shown, it should be emphasized that the teachings of the present disclosure are applicable to systems that employ any number of sources (e.g., 1, 2, 3, or 5 or more). As understood in the art, each melting beam source 212, 214, 216, 218 may each have a field including non-overlapping field regions in which the melting beam source may exclusively melt the metal powder, and the melting beam source may include at least one overlapping field region in which two or more sources may melt the metal powder. In this regard, each melt beam source 212, 214, 216, 218 can generate a melt beam that melts the particles of each slice, as defined by code 2340. Figure 5 In the embodiment of the present invention, melt beam source 212 is shown as forming a layer of metal coupon 200 using melt beam 262 in one area, while melt beam source 214 is shown as forming a layer of metal coupon 200 using melt beam 262' in another area. Each melt beam source 212, 214, 216, 218 is calibrated in any manner now known or later developed. That is, each melt beam source 212, 214, 216, 218 has an expected position of its laser or electron beam relative to the build platform 220 in relation to the actual position of the laser or electron beam so as to provide a separate position correction (not shown) to ensure its separate accuracy. In one embodiment, each of the plurality of melt beam sources 212, 214, 216, 218 can form a melt beam, such as 262, 262', having the same cross-sectional size (e.g., shape and size in operation), power and / or scanning speed.

[0070] Continue to refer Figure 5, coater (or recoater blade) 270 can form a thin layer of raw material 272, which is spread out as a blank canvas from which each successive slice of the final coupon will be formed. Various parts of AM printer 232 can move to accommodate the addition of each new layer, for example, after each layer, build platform 220 can be lowered and / or chamber 260 and / or coater 270 can be raised. The process can use different raw materials in the form of fine-grained metal powders, and reserves of these raw materials can be maintained in chamber 260 accessible by coater 270. In this case, coupon 200 can be made of metal, which can include pure metals or alloys. In one example, the metal can include nearly any non-reactive metal powder, i.e., non-explosive or non-conductive powder, such as, but not limited to: cobalt-chromium-molybdenum (CoCrMo) alloy; stainless steel; austenitic nickel-chromium based alloys, such as nickel-chromium-molybdenum-niobium alloy (NiCrMoNb) (e.g., Inconel 625 or Inconel 718); nickel-chromium-iron-molybdenum alloy (NiCrFeMo) (e.g., available from Haynes International, Inc. X); or nickel-chromium-cobalt-molybdenum alloy (NiCrCoMo) (such as Haynes 282 available from Haynes International, Inc.). Other possibilities include, for example, René 108, CM 247, Mar M 247, and any precipitation hardenable (PH) nickel alloy.

[0071] The processing chamber 260 is filled with an inert gas such as argon or nitrogen and is controlled to minimize or eliminate oxygen. The control system 230 is configured to control the flow of the gas mixture 274 from the inert gas source 276 in the processing chamber 260. In this case, the control system 230 can 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 can 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 may be provided with or without the valve system 282. In the case of omitting the pump 280, the inert gas can simply enter the pipeline or manifold before being introduced into the processing chamber 260. The inert gas source 276 can take the form of any conventional source for the material contained therein, such as a tank, a storage or other source. Any sensor (not shown) required for measuring the gas mixture 274 can be provided. The gas mixture 274 can be filtered in a conventional manner using a filter 286.

[0072] In operation, a build platform 220 with metal powder thereon is disposed within a process chamber 260, and a control system 230 controls the flow of a gas mixture 274 from an inert gas source 276 within the process chamber 260. According to an embodiment of the present disclosure, the control system 230 also controls the AM printer 232, in particular the coater 270 and the melting beam sources 212, 214, 216, 218, to sequentially melt the metal powder layers on the build platform 220, thereby generating a metal coupon 200.

[0073] Although a particular AM system 210 has been described herein, it should be emphasized that the teachings of the present disclosure are not limited to any particular additive manufacturing system or method. Furthermore, although the teachings of the present disclosure relate to additively manufacturing metal coupon 200, it will be appreciated that component 202 may be manufactured in any now known or later developed manner, such as additive manufacturing (which may be similar to the additive manufacturing described for metal coupon 200), casting, or other methods. Component 202 may include any of the materials listed herein for metal coupon 200.

[0074] 7A to 7E A perspective view of an illustrative additively manufactured (AM) metal coupon 200 including an AM component 290 having one or more porous regions 300 with pores 302 is shown.

[0075] As used herein, "porosity" is the ratio of the volume of open space to the total volume of the structure (e.g., porous region, metal coupon, etc.). In this regard, porosity is generally expressed as the volume of open space as a percentage of the overall volume or total volume of the structure. Open space is the empty area in a solid material and may be referred to as "pores" 302 herein and may include interconnecting channels in the material of the structure being described. Thus, a "porous region" in a metal coupon 200 is less than 100% solid and includes open space in the form of pores 302 and / or interconnecting channels. A porous metal coupon 200 may include solid regions, but also one or more porous regions that are less than 100% solid. As used herein, the three-dimensional boundaries of a porous region or sub-region used to identify its "total volume" may be identified by a porosity change of greater than 2% relative to adjacent regions or sub-regions within the metal coupon 200 and / or the presence of an edge of the metal coupon 200. "Open space volume" refers generally to the empty three-dimensional space (i.e., voids, gaps, empty spaces) and / or unfilled material within a region or sub-region. As used herein, "different porosities" or "differences in porosity" generally means any kind of characteristics, such as: the percentage of open space volume to total volume, the number of pores 302 in a given volume, the volume (i.e., size) of pores 302, the shape of pores 302, and the variation of connecting channels between pores 302 (which may not be considered actual discrete pores) (referred to herein as "pore connecting channels"). As a non-limiting example only, the pore size may be, for example, 1.07×10 -6 Cubic millimeters to 8.58×10 -3 Cubic millimeters (6.54×10 -11 Cubic inches to 5.24×10 -7 In some embodiments, the pore size may be in the range of 0.0127 millimeters (mm) to 0.254 mm (0.0005 inches to 0.01 inches). In cases where there are differences, such as pore shape or pore connecting channels, it will be recognized that the difference in porosity may not be based solely on the percentage of open space volume to total volume. However, in cases where differences in porosity are compared in terms of degree (e.g., higher or lower), the difference referred to is simply the difference in volumetric properties, i.e., the percentage of open space volume to total volume. In the accompanying drawings, different porous regions or sub-regions are generally shown as continuous or in contact with each other, however it should be emphasized that these porous regions or sub-regions can be isolated from each other in any manner, such as having solid areas between these porous regions or sub-regions. That is, a single metal coupon may include one or more isolated, non-contacting porous regions.

[0076] The porous metal coupon 200 including different porous regions with different porosities can be formed using the AM system 210 as described herein or any other metal additive manufacturing system or method capable of forming porous metal (and solid metal). In terms of the operation of the AM system 210, the melting beam sources 212, 214, 216, 218 can be programmed to intermittently not sinter the metal to leave metal powder instead of solid material. This process can include overlapping the laser field area by different amounts and / or designing the holes 302 into the build file, i.e., code 234O. Less overlap per laser scan forms a larger porosity, and more laser overlap between consecutive scans forms a smaller porosity. The laser spot size, scan speed, focal length, and power can also be controlled to adjust the porosity. When the unmelted metal powder is removed from the metal coupon 200, it leaves holes 302 with interconnecting channels between the holes 302 and forms one or more porous regions in the metal coupon 200. In any case, the layered fabrication of the metal coupon 200 may be controlled to form a desired porosity for any number, shape, and / or size of porous regions within any desired layer of the metal coupon 200 .

[0077] FIG. 6A to FIG. 6D A top view schematic diagram of non-limiting sample metal coupons 200 having different porosities is shown. The pores 302 are shown as darker open spaces in the figure. Fig. 6A A sample metal coupon 200 having a first porosity with an open space volume of approximately 40% of the total volume of the sample (with a generally high amount of open space and more or larger pores 302) is shown. Figure 6B A sample metal coupon 200 is shown having a first porosity with an open space volume of approximately 30% of the total volume of the sample. Figure 6C A sample metal coupon 200 is shown having a first porosity with an open space volume of approximately 20% of the total volume of the sample. Fig.6DA sample metal coupon 200 is shown having a first porosity of approximately 10% open space volume to the total volume of the sample (having a generally low amount of open space). Each porous region may have a porosity of 2% to 50% open space volume to the total volume of the porous region (i.e., 2% to 50% open space and the other 50% to 98% solid). In other embodiments, each porosity may be 10% to 40% open space volume to the total volume of the porous region 300 (i.e., 10% to 40% open space and the other 60% to 90% solid). In other embodiments, a porous area may be provided in the metal coupon 200 having a porous area in the range of less than 10%, in the range of less than 15%, in the range of less than 20%, in the range of less than 25%, in the range of less than 30%, in the range of less than 35%, in the range of less than 40%, in the range of less than 45%, in the range of 2% to 45%, in the range of 2% to 40%, in the range of 2% to 35%, in the range of 2% to 30%, in the range of 2% to 25%, in the range of 2% to 20%, in the range of 5% to 45%, in the range of 5% to 40%, in the range of 5% to 35%, in the range of 5% to 30%, in the range of 5% to 25%, in the range of 5% to 45%, in the range of 5% to 40%, in the range of 5% to 35%, in the range of 5% to 30%, in the range of 5% to 25%, or in the range of 5% to 25%. In some embodiments, the present invention relates to a porosity within the range of 5% to 20%, within the range of 10% to 45%, within the range of 10% to 40%, within the range of 10% to 35%, within the range of 10% to 30%, within the range of 10% to 25%, within the range of 10% to 20%, within the range of 15% to 45%, within the range of 15% to 40%, within the range of 15% to 35%, within the range of 15% to 30%, within the range of 15% to 25%, within the range of 15% to 20%, within the range of 10% to 50%, within the range of 20% to 50%, within the range of 25% to 50%, within the range of 30% to 50%, within the range of 35% to 50%, within the range of 40% to 50%. Other ranges of porosity are also possible as will be described herein.

[0078] Fig. 7A A metal coupon 200 is shown including a single porous region 300 having a first porosity (the entire coupon 200 having the first porosity); Figure 7B A metal coupon 200 is shown comprising more than one (layered) porous regions 300A-300B of different porosities; Figure 7C A metal coupon 200 is shown including one or more porous regions 300A-300B having different porosities and a solid region 304; Fig.7DA metal coupon 200 is shown having a variable porosity region 300D located between (and possibly including) a first porous region 300A and a second porous region 300B; and Fig. 7E A metal coupon 200 is shown including more than one (opposite) porous regions 300A-300B having different porosities. Figure 3 and Figure 4 As shown, 7A to 7E The metal coupon 200 in FIG. 1 is shown as having a shape configured to be positioned in a coupon opening 204 in the trailing edge 158 or 184 of the blade 132 or nozzle 126, respectively, or in a coupon opening 204 in the leading edge 156 or 182 of the blade 132 or nozzle 126, respectively. The metal coupon 200 may also be positioned in any tip (not shown) of the blade 132 or the platform 170 (shown), 174 of the nozzle 126. However, it should be emphasized that the metal coupon 200 may be used in any coupon opening 204 in any portion of the body 206 of any component 202.

[0079] More specifically, if Fig. 7A As shown, the metal coupon 200 may include a first porous region 300 having a first porosity. Fig. 7A In FIG. 1 , the metal coupon 200 includes a single porous region 300 having a single first porosity. Fig. 7A In the embodiment, the entire metal sample block 200 includes the first porosity. Therefore, each layer of the metal sample block 200 has the same porosity. Figure 7B and Fig. 7E In FIG. 1 , the metal coupon 200 includes two porous regions 300A to 300B each having a different porosity. Figure 7B In the embodiment, the two different porous regions 300A and 300B are a layered inner region and an outer region, one of which is closer to the inside of the metal specimen than the other, and Fig. 7E In FIG. 2 , two different porous regions 300A, 300B are different sides of the metal coupon 200. The region within the layer of the metal coupon 200 defining the regions 300A to 300B may be formed to include pores 302. Figure 7C In the embodiment of the present invention, metal coupon 200 includes one or more porous regions 300C and solid regions 304, each of which may have the same or different porosities. Here, the regions within the layers of metal coupon 200 defining regions 300A to 300B may be formed to include pores 302, and the regions within the layers of metal coupon 200 defining solid regions 304 may be formed to be free of pores 302. Fig.7D, the metal sample block 200 includes a variable porosity region 300D located between the first porous region 300A and the second porous region 300B (and may include a portion of the first porous region and the second porous region). Here, the area defining the regions 300A to 300B or the variable porosity region 300D within the layer of the metal sample block 200 can be formed to include, for example, different sizes or numbers of pores 302 to form different porosities. The variable porosity region 300D can have any porosity that changes (e.g., increases, decreases, and / or both increases and decreases). The change in porosity can be gradual or step-wise or otherwise incremental. Although the variable porosity region 300D is Fig.7D is shown as being between the inner porous region 300A and the outer porous region 300B, as shown in Figure 7B As in, but variable porous area can also be applied to Fig. 7E Each porous region 300 may have a porosity of 2% to 50% (i.e., 2% to 50% open space and 50% to 98% solid) of the total volume of the porous region 300. In other embodiments, each porosity may be 10% to 40% (i.e., 10% to 40% open space and 60% to 90% solid) of the total volume of the porous region 300. Other ranges of porosity are also possible. For example, the porous region 300 may have any porosity described herein.

[0080] refer to Figure 3 , Figure 4 , 7A to 7E and FIG. 8A to FIG. 8F , embodiments of methods according to the present disclosure will now be described. The method may include coupling a metal coupon in a component 202, such as for performing a repair. FIG. 8A to FIG. 8F A perspective view of a method according to an embodiment of the present disclosure is shown.

[0081] Fig. 8A A coupon opening 204 is shown formed in the body 206 of the component 202. The coupon opening 204 is configured to receive the metal coupon 200. The coupon opening 204 may have any desired shape. In some applications, the coupon opening 204 is formed by removing a damaged portion of the body 206 of the component 202, but the coupon opening 204 may also be in the original version of the component 202, for example, at a location that is challenging to manufacture with the rest of the component 202. In the non-limiting example shown, the coupon opening 204 is located in the trailing edge 184 of the nozzle 126. Fig. 8AAlso shown is a model of the coupon opening 204. Model formation may include using any now known or later developed three-dimensional scanner (not shown, see arrow) to scan and form a digital representation of the coupon opening 204 relative to the body 206 of the component 202. Since methods of scanning and modeling parts are well known in the art, further details are omitted so that the reader can focus on the salient aspects of the present disclosure.

[0082] Figure 5 , Figure 7B , Fig.7D and Fig. 7E An additively manufactured metal coupon 200 is shown including a first porous region 300A having a first porosity and a second porous region 300B having a second porosity different from the first porosity. Fig. 7A Also shown is a metal coupon 200 formed to have a single porosity (not solid); and Fig.7DAlso shown is the formation of a metal coupon 200 having a variable porosity region 300D located between the first porous region 300A and the second porous region 300B and possibly including portions of the first porous region and the second porous region. The variable porosity region 300D may include a porosity that gradually changes from the porosity of the first porous region 300A to the porosity of the second porous region 300B. As noted, the porosity change may be gradual, step-like, or incremental. The first porosity region, the second porosity region, and the variable porosity region differ from each other in at least one of the following characteristics: the percentage of open space volume to total volume, pore shape, pore size, number of pores, or pore connecting channels. Additive manufacturing may include any AM method described herein to manufacture a porous metal coupon 200 (or a dense region or a solid region). Additive manufacturing may include selectively forming a porous region 300 in a solid region of the metal coupon 200 by controlling an AM printer 232. Additive manufacturing may include manufacturing the metal coupon 200 to substantially match the profile (e.g., shape, size, etc.) of the coupon opening 204, or to have a near net shape of the coupon opening 204 based on a model of the coupon opening 204. As used herein, "near net shape" indicates that the metal coupon 200 is within desired manufacturing tolerances, with no or minimal additional processing (e.g., machining) at a specified stage of the manufacturing method. Some additional texturing or polishing of the outer surface may be desired. It should be recognized that additional coatings may be applied once the metal coupon 200 is in the component. When formed to a near net shape, the metal coupon 200 may also have a certain shape after manufacturing that, when positioned in the coupon opening 204, closely approximates the surface of the body 206 required to couple the metal coupon 200 in the coupon opening 204 (e.g., using a selected brazing material and no or minimal required finishing methods (such as machining or grinding)). However, the use of porous regions 300 in metal coupon 200 accommodates greater variations in joint gap size than a solid coupon with a narrow gap for the brazing material because the porous regions provide improved brazing material grip and retention despite the larger gap. FIG. 8B to FIG. 8C is shown as Figure 7B The invention may be additively manufactured as in the embodiments described herein, but it may take any form described herein.

[0083] According to embodiments of the present disclosure, the porosity of one or more porous regions 300 in the metal coupon 200 is controlled (i.e., customized) to provide a porous region 300 that is porous enough to permit the metal coupon 200 to be coupled to the coupon opening 204 (e.g., Figure 3 , Figure 4 and 9A to 9DThe flow of the brazing material in the one or more porous regions can be controlled during the subsequent brazing process in the embodiment shown in FIG. Each porous region 300 can be customized according to any of the aforementioned characteristics that affect porosity. In addition, the shape and / or position of the porous region 300 can be arranged to guide the brazing material as needed. For example, in Fig. 7A In the embodiment of FIG. 1 , the entire metal coupon 200 includes the first porous region 300, so the brazing material will be evenly distributed therein. In contrast, in Figure 7B In the embodiment, the metal coupon 200 includes a porous region 300A near an edge 306 of the metal coupon 200 (where it will be in contact with the coupon opening 204 ( Figure 3 to Figure 4 ) connection) and different porous regions 300B having different porosities adjacent to the first porous region 300A (e.g., away from the edge 306). In this way, the brazing material 310 will be distributed in each porous region 300 in a different manner, resulting in different physical properties of the metal coupon 200 in different regions thereof. More specifically, any number of porous regions 300 may be used to tailor (form) at least one different physical property in the component 202 including the metal coupon 200, such as: joint adhesive bond strength, coupon strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, cyclic fatigue, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or quality. In a non-exhaustive list of possibilities, the metal coupon 200 may include a higher porosity in one region 300 compared to other solid regions of the metal coupon 200 to guide more brazing material therein by capillary action, thereby controlling at least one physical property of the component 202. In another embodiment, the metal coupon 200 may include a lower porosity in one region 300 to direct less braze material therein by capillary action compared to other solid regions of the metal coupon 200, thereby controlling at least one physical property of the component 202. In other embodiments, the metal coupon 200 may include two or more porous regions 300 that together comprise the entire metal coupon 200. Any arrangement of the porous regions 300 may produce the desired braze material flow and penetration.

[0084] In certain embodiments, additive manufacturing may also include forming any type of modification to component 202 in metal coupon 200, including, for example, structures that did not previously exist in component 202. Component 202 may be an original component that needs modification or a component that includes removed or damaged portions. Figure 8CAs shown, additive manufacturing may optionally include forming a cooling channel 320 in the metal coupon 200. The cooling channel 320 may extend in any manner in the metal coupon 200, such as extending in a serpentine path in the metal coupon or extending through an exterior surface 322 of the metal coupon 200. In another example, as shown in FIG. 7A to 7E As shown, additive manufacturing may optionally include forming one or more support and / or cooling structures 324 (e.g., pins / fins) in the metal coupon 200 (perhaps with cooling channels therein (not shown)). Any advantageous internal structural changes may be made in the metal coupon 200. The metal coupon 200 may optionally be subjected to any now known or later developed post-additive manufacturing finishing process, such as grinding to smooth its surface. Advantageously, however, the teachings of the present disclosure eliminate the need for other finishing steps (e.g., shot peening, heat treatment, hot isostatic pressing (HIP), etc.) that are typically used to address residual stresses present in the material after additive manufacturing. Figure 8B and Figure 8C A metal coupon 200 is shown positioned in a coupon opening 204 in a body 206 of a component 202. The metal coupon 200 may be positioned in the coupon opening 204 in the body 206 in any now known or later developed manner (e.g., using a robotic arm or manually). If necessary, the metal coupon 200 may be held in place in any desired manner (e.g., adhesively, clamped, nickel-chrome tack welding, roller ball bonding, resistance welding, fusion tack welding, etc.).

[0085] FIG. 8D to FIG. 8E The metal coupon 200 is shown infiltrated with a brazing material 310 to join the metal coupon in the coupon opening 204 in the body 206, i.e., to perform a brazing process. The brazing material 310 may include any now known or later developed brazing composition, such as, but not limited to: GE (Alstom) B1P, Amdry TM D15, DF4B or BRB, some formulations of these brazing compositions are listed in the following table together with other brazing material formulations:

[0086]

[0087] Infiltration may include any now known or later developed brazing method, such as using 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, applying a brazing material ( Fig.8D ) and applying heat ( Fig. 8E ), thereby causing the brazing material to flow into, through, and around the metal sample block 200 by capillary action.

[0088] The brazing material 310 is injected into at least one of the first porous region 300A and the second porous region 300B based on at least the characteristics of the first porosity and at least the characteristics of the second porosity. Fig.7D ) is present, the infiltration includes causing the brazing material 310 to travel through and infiltrate the first porous region 300A based on the characteristics of the first porosity, travel through and infiltrate the variable porosity region 300D based on the characteristics of the variable porosity region 300D (e.g., a gradient of porosity, stepped porosity, etc.), and travel through and infiltrate the second porous region 300B based on the characteristics of the second porosity.

[0089] The different porosities of porous regions 300A, 300B and perhaps variable porosity regions 300D cause different brazing materials 310 to flow and penetrate. Due to the brazing method, the first porous region 300A and the second porous region 300B containing the brazing material 310 have at least one different physical property. In the presence of variable porosity region 300D, it may have physical properties different from the first porous region 300A and the second porous region 300B. Therefore, due to the brazing method, the first porous region 300A and the second porous region 300B (and possible variable porous region 300D) containing the brazing material 310 in the component 202 have at least one different physical property. For example, more brazing materials 310 can produce stronger joint adhesive bonding strength, higher ductility, higher thermal conductivity or electrical conductivity or higher oxidation resistance, and less brazing materials 310 can produce less surface roughness, less hardness, lower joint adhesive bonding strength, lower ductility, lower thermal conductivity or electrical conductivity or lower oxidation resistance. In any case, controlling the amount of brazing material and the porosity of different porous regions allows controlling the physical properties of the final product. In one example, the first porosity of the first porous region 300A may be higher than (i.e., less dense) the second porosity of the second porous region 300B. In this case, infiltration includes infiltrating the first porous region 300A with more brazing material 310 than the second porous region 300B. Depending on the brazing material 310 used, among other factors, different porosities allow at least one physical property of the customized component 202, such as: bonding strength of the joint adhesive, stress resistance / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness and / or quality. In addition, compared with conventional narrow gap filling brazing methods and due to the strict manufacturing tolerances required for narrow gap brazing, the multi-flow paths for the brazing material 310 using the porous region 300 can reduce the possibility of lack of filling and / or voids along the brazing joint. Thus, despite the use of a metal coupon 200 having a porous region 300 in a component 202, the component may still be at least 98% solid.

[0090] In certain embodiments, different brazing materials 310 may be used in different portions of the metal coupon 200, thereby providing further customization of the physical properties of the metal coupon 200 and regions of the component 202. Fig. 9C and Fig.9D , a first braze material 310A may be used on a first portion or side 326 of the component 202, and another braze material 310B different from the first braze material 310A may be used on a different portion or side 328 of the component 202. In one example, referring to Figure 3 , Figure 4 and Fig. 9C , the first portion or side 326 of the component 202 may be the first (concave pressure) side outer wall 152, 178 of the airfoil 150, 176, and the second or side 328 of the component 202 may be the second (convex suction) side outer wall 154, 180 of the airfoil 150, 176. In addition to the different porous regions 300, the different braze materials 310A, 310B on the different portions or sides 326, 328 may be tailored to the expected environment of the component 202 at those locations. As will be appreciated, the variations in braze materials and / or porous regions that may address different situations are enormous.

[0091] Other embodiments of methods according to the present disclosure may include forming only the metal coupon 200 for repairing the component 202. In this case, Fig. 8A As shown, the method includes forming a model of a coupon opening 204 in a body 206 of a component 202, and additively manufacturing a metal coupon 200 to at least closely fit the coupon opening 204, e.g., to have a near net shape of the coupon opening 204. As described herein and FIG. 7B to FIG. 7E As shown, the metal coupon 200 may include at least a first porous region 300A having a first porosity and a second porous region 300B having a second porosity different from the first porosity. After the metal coupon 200 is coupled in the coupon opening 204 using the brazing material 310, the different first porosities and second porosities produce different physical properties.

[0092] Fig.8F Exemplary optional finishing steps for component 202 are shown, such as, but not limited to, machining to smooth the outer surface and remove excess braze material. As noted, the teachings of the present disclosure eliminate other finishing steps that are typically required to address residual stresses present in the material after additive manufacturing, such as shot peening, heat treatment, hot isostatic pressing (HIP), etc.

[0093] Figure 3 , Figure 4 and 9A to 9DAn embodiment of a component 202 according to an embodiment of the present disclosure is shown, wherein 9A to 9D An enlarged cross-sectional view of a metal coupon 200 over a coupon opening 204 of a body 206 of a component 202 is shown. Fig. 9A A component 202 is shown including a metal coupon 200 having a single porous region 300, Fig. 9B A component 202 is shown including a metal coupon 200 having two or more porous regions 300A, 300B, Fig. 9C A component 202 is shown including a metal coupon 200 having two or more layered porous regions 300A, 300B and different brazing materials 310A, 310B, and Fig.9D A component 202 is shown that includes a metal coupon 200 having two porous regions 300A, 300B and different brazing materials 310A, 310B on different sides 326, 328 of the metal coupon 200. The component 202 includes a body 206. As noted herein, the body 206 may have any form useful for the particular industrial application in which the component 202 is used. In the example used herein, the body 206 may include a turbine rotating blade 132 ( Figure 3 ) or turbine fixed nozzle 126 ( Figure 4 ). Although the metal sample block 200 is, for example, Figure 3 and Figure 4 132 and the airfoil 150, 176 of the nozzle 126, respectively, but the metal coupon 200 may be located in any portion of the body 206 of the component 202. The additively manufactured (AM) metal coupon 200 includes at least a first porous region 300A having a first porosity, as described herein with respect to 7A to 7E The brazing material 310 couples the metal coupon 200 in the coupon opening 204 in the body 206. Fig. 9A As shown, the brazing material 310 includes a first section 330 that infiltrates into the first porous region 300A based at least on the characteristics of the first porosity. Fig. 9B and Fig.9DAs shown, the metal sample block 200 also includes a second porous region 300B having a second porosity different from the first porosity. The first porosity can be different from the second porosity in at least one of the following characteristics: the percentage of open space volume to total volume, pore shape, pore size, number of pores, or pore connecting channels. The body 206 can 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 both the first porosity and the second porosity, for example, it may be 100% solid. Optionally, the metal sample block 200 may include a variable porosity region 300D (in between) located between the first porous region 300A and the second porous region 300B (and may include a portion of the first porous region and the second porous region). Fig. 9B Variable porosity region 300D may gradually change porosity between the first porosity and the second porosity, for example, in a stepwise or incremental manner. Fig. 9B In FIG. 2 , different porous regions 300A, 300B are layered one inside the other in the metal coupon 200. Fig.9D In FIG. 2 , the different porous regions 300A, 300B are on opposite sides of the metal coupon 200 .

[0094] exist Fig. 9B , the brazing material 310B includes a second section 332 that penetrates into the second porous region 300B based at least on a characteristic of the second porosity. The "at least one characteristic" of the porosity indicates that the porosity can result in different penetration characteristics, such as brazing material volume, intra-porosity mode, crystallization, chemical gradient and composition, and other characteristics. However, as understood in the art, other factors can also affect the penetration characteristics, such as the type of brazing material and the characteristics of the brazing method, such as but not limited to: temperature, pressure, positioning of the component 202 and the metal coupon 200. As a result of the different porosities, the first porous region 300A and the second porous region 300B having the brazing material 310 have at least one different physical property. Because the porosity can affect those physical properties, the porosity can be customized to select those physical properties. In one example, the first porous region 300A may have a first porosity that is higher (i.e., less dense) than the second porous region 300B, and the first porous region 300A may include more brazing material 310 therein than the second porous region 300B. Fig. 9B As shown, the first porous region 300A is located in at least a portion of the edge 306 of the metal coupon 200 configured to be joined to the body 206, while the second porous region 300B is located further inside the metal coupon 200. In another example, as shown in FIG. Fig.9DAs shown, the first porous region 300A is located in one side 326 of the metal coupon 200, and the second porous region 300B is located in the opposite side 328 of the metal coupon 200. In this way, different sides of the metal coupon 200 and the component 202 can have different physical properties. Figure 3 and Figure 4 As shown in , the pressure side outer walls 152, 178 of the airfoil may have different physical properties than the suction side outer walls 154, 180 of the airfoil, respectively. In any case, the second porous region 300B may be adjacent to the first porous region 300A. Alternatively, the second porous region 300B may also be adjacent to at least (another) portion of the edge 306 of the metal coupon 200, and may be adjacent to the first porous region 300A. Fig. 9B As shown, this arrangement can advantageously place more braze material 310 near the braze joint 334 to enhance the joint adhesive bond strength of the metal coupon 200 in the coupon opening 204 in the body 206, or it can allow for less oxidation at the braze joint 334 or greater thermal conductivity at the braze joint 334. Any of the physical properties described herein can also be customized based on different porosities and / or different braze materials. As noted, depending on the braze material 310 used, different porosities can allow for customization of the physical properties of the component 202, such as: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or quality.

[0095] exist Fig.9D In the embodiment, the brazing material 310B also includes a second section 332 that penetrates into the second porous region 300B based at least on the characteristics of the second porosity. Fig.9D In the example of FIG. 1 , the first porous region 300A is located in one side 326 of the metal coupon 200, and the second porous region 300B is located in the opposite side 328 of the metal coupon 200. In this way, different sides of the metal coupon 200 and the component 202 may have different physical properties. Figure 3 and Figure 4 As shown in , the pressure side outer walls 152, 178 of the airfoil may have different physical properties than the suction side outer walls 154, 180 of the airfoil, respectively. In any case, the second porous region 300B may be adjacent to the first porous region 300A. Fig.9DAs shown, this arrangement can advantageously place more braze material 310 near the braze joint 334 on the side 326 to enhance the joint adhesive bond strength of the metal coupon 200 in the coupon opening 204 in the body 206, or it can allow less oxidation at the braze joint 334 or greater thermal conductivity at the braze joint 334. Any of the physical properties described herein can also be customized based on different porosities and / or different braze materials. As noted, depending on the braze material 310 used, different porosities can allow customization of the physical properties of the component 202, such as: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or quality.

[0096] As noted, the metal coupon 200 may have a near net shape of the coupon opening 204 in the body 206 of the component 202. Figure 8C As shown, the metal coupon 200 may optionally include a cooling channel 320 therein. The cooling channel 320 is defined in the metal coupon 200 and may extend through an exterior surface 322 of the metal coupon.

[0097] Although specific locations of the different porous regions 300 have been illustrated herein, it should be emphasized that the different porous regions may be arranged in any manner to provide different braze material penetration characteristics and different physical properties to the component 202 .

[0098] like Figure 1 to Figure 2 As shown in , embodiments of the present disclosure may also include a turbine 100 including a turbine assembly 110 and at least one component 202, as described herein. The component 202 may take the form of a turbine stationary nozzle 126, a turbine rotating blade 132, or other component of the turbine 100. The metal coupon 200 may be used in a newly manufactured component or in a component that needs repair or improvement.

[0099] The present disclosure provides various technical and commercial advantages, examples of which are discussed herein. For the repair or improvement of parts, additive manufacturing allows cost-effective production of metal coupons with customized fitting shapes when only damaged material needs to be removed. The porous region can provide a higher percentage of the base metal alloy (e.g., >60%) in certain areas, which can produce improved physical properties compared to, for example, pre-sintered preforms. The porous region can also provide a welding / molten particle matrix (e.g., with a superalloy metal substrate) with a brazing material filler, which is stronger than conventional metal particles surrounded by the brazing material. Compared with conventional narrow gap filling brazing methods, the multi-flow path of the brazing material using the porous region can also reduce the possibility of lack of filling and / or voids along the brazing joint. The porous region can be formed to have a porosity difference across the metal coupon to allow highly customized brazing material flow. Compared with a mechanically processed solid coupon with a narrow gap for the brazing material, the porous region also adapts to large joint gap size changes. Repairs using the teachings of the present disclosure are stronger than conventional narrow gap brazing methods, do not require specific post-repair finishing, and also provide improved physical properties compared to current technologies such as pre-sintered preforms (PSPs).

[0100] As used throughout the specification and claims, approximate language can be used to modify any quantitative representation that can be permitted to vary without resulting in a change in the basic function to which it is associated. Therefore, values ​​modified by one or more terms (such as "about", "approximately" and "substantially") are not limited to the precise values ​​specified. In at least some cases, approximate language can correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range limitations can be combined and / or interchanged; unless the context or language indicates otherwise, these ranges are identified and include all subranges contained therein. "About" or "approximately" applied to a particular value of a range applies to both end values ​​and may indicate + / -10% of the value unless otherwise dependent on the precision of the instrument for measuring the value.

[0101] The corresponding structures, materials, actions and equivalents of all means or steps plus function elements in the following claims are intended to include any structure, material or action for performing functions in conjunction with other claimed elements specifically claimed. A description of the present disclosure has been given for the purpose of illustration and description, but it is not intended to be exhaustive or to limit the present disclosure to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and essence of the present disclosure. Embodiments have been selected and described in order to best explain the principles and practical applications of the present disclosure, and to enable other persons of ordinary skill in the art to understand the various embodiments of the present disclosure and various modifications thereof suitable for the intended specific use.

Claims

1. A method of coupling a metal coupon (200) in a component (202), the method comprising: Additively manufacturing a metal coupon (200) having a first porous region (300A) and a second porous region (300B), wherein the first porous region has a first porosity and the second porous region has a second porosity different from the first porosity; positioning the metal coupon (200) in a coupon opening (204) in a body (206) of the component (202); as well as The metal coupon (200) is infiltrated with a brazing material (310) to couple the metal coupon (200) to the coupon opening (204) in the body (206), wherein the infiltrating includes infiltrating the brazing material (310) into at least one of the first porous region (300A) and the second porous region (300B) based at least on a characteristic of the first porosity and based at least on a characteristic of the second porosity.

2. The method of claim 1, wherein the first porous region (300A) and the second porous region (300B) containing the brazing material (310) have at least one different physical property.

3. The method of claim 1, wherein the additive manufacturing comprises forming the metal coupon (200) having a variable porosity region (300D) located between and including the first porous region (300A) and the second porous region (300B).

4. The method of claim 3, wherein infiltrating the metal coupon (200) with the brazing material (310) comprises causing the brazing material (310) to travel through and infiltrate the first porous region (300A) based on the characteristics of the first porosity, to travel through and infiltrate the variable porosity region (300D) based on the characteristics of the variable porosity region (300D), and to travel through and infiltrate the second porous region (300B) based on the characteristics of the second porosity.

5. The method of claim 1, wherein the first porosity differs from the second porosity in at least one of the following characteristics: percentage of open space volume to total volume, pore shape, pore size, number of pores (302), and pore connecting channels.

6. The method of claim 4, wherein the first porosity is higher than the second porosity, and wherein the infiltrating comprises infiltrating the first porous region (300A) with more brazing material (310) than the second porous region (300B).

7. The method of claim 1, wherein the at least one different physical property is selected from the group consisting of: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and mass.

8. The method of claim 1, wherein the additive manufacturing comprises forming a cooling channel (320) in the metal coupon (200).

9. The method of claim 1, wherein the infiltrating comprises using vacuum brazing, induction brazing, or inert gas atmosphere heating.

10. The method according to claim 1, further comprising, before the additive manufacturing: forming the coupon opening (204) in the body (206) configured to receive the metal coupon (200); and forming a pattern of the sample block opening (204), The additive manufacturing includes manufacturing the metal coupon (200) based on the model of the coupon opening (204).

11. The method of claim 10, wherein the additive manufacturing comprises manufacturing the metal coupon (200) to a near-net shape of the coupon opening (204) based on the model of the coupon opening (204).

12. A method according to claim 10, wherein the infiltration includes infiltrating a first brazing material (310A) into the first porous region (300A) based at least on the characteristics of the first porosity, and infiltrating a different second brazing material (310B) into the second porous region (300B) based at least on the characteristics of the second porosity.

13. A method of forming a metal coupon (200) for a component (202), the method comprising: forming a pattern of a coupon opening (204) in a body (206) of the component (202); as well as performing additive manufacturing (AM) on the metal coupon based on the model of the coupon opening (204), the metal coupon (200) comprising at least a first porous region (300A) having a first porosity and a second porous region (300B) having a second porosity different from the first porosity, The different first and second porosities thereby produce different physical properties after the metal coupon (200) is coupled in the coupon opening (204) using a brazing material (310).

14. The method of claim 13, wherein the additive manufacturing comprises manufacturing the metal coupon (200) to a near-net shape of the coupon opening (204) based on the model of the coupon opening (204).

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