Metallic specimen block with porous regions and inclined sidewalls for turbine components

Abstract

An additive manufacturing (AM) metal sample block (200) for a turbine component (202) is provided. The component (202) includes an airfoil body (206) having a pressure side (152, 178), a suction side (154, 180), a trailing edge (158, 184), and a mass opening (204). The AM metal sample block (200) has an AM metal member (290) having at least one inclined sample block side wall (292, 294) that forms an angle of less than 90 DEG with an outer surface (296) of the AM metal member (290). The AM metal member (290) further includes 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 braze material (310) couples the AM metal specimen block (200) in a specimen block opening (204) in the airfoil body (206), and the braze material permeates 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.

Description

Technical Field

[0001] The present disclosure relates generally to component repair and fabrication, and more particularly, to turbine components using a metal coupon having two porous regions and a sloped sidewall. Background Art

[0002] Industrial components sometimes need repair. For example, hot gas path components used in turbines to direct working fluid to generate energy may need repair. Hot gas path components can take many forms, such as turbine rotating blades or fixed guide vanes including airfoils that direct working fluid to create energy. The rotating blades are coupled to the turbine rotor and are used to rotate the turbine rotor, and the fixed guide 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 approximately 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 the replacement of the sample block. However, the replacement sample block is made of the material and external structure identical with the removed part of the parts. Therefore, the replacement sample 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 sample block 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 sample block and connect it to the parts, which has stopped improving the general performance characteristics listed above and the additional performance characteristics relevant with the joint, such as increasing the joint adhesive bonding strength and reliability, and reducing required brazing post-processing / mixing. Use the sample block substantially identical with the incision removed and do not allow to reduce the high material cost of the replacement sample block. Another challenge is to ensure to connect the sample block for a long time with the intensity identical with the incision. 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 metal sample block, which includes: an additively manufactured (AM) metal component, which has: at least one inclined sample block sidewall that is at an angle less than 90° to the outer surface of the AM metal component; a first porous region, which has a first porosity; a second porous region, which has a second porosity different from the first porosity, wherein the first porosity and the second porosity are open space volumes of 2% to 50% of the total volume of the first porous region and the second porous region, respectively.

[0007] Another aspect of the present disclosure includes any of the foregoing aspects, and the AM metal component includes a variable porosity region between the first porous region and the second porous region.

[0008] Another aspect of the present disclosure includes any of the aforementioned aspects, and the AM metal component further includes an inclined end wall that makes an angle of less than 90° with an outer surface of the AM metal component.

[0009] Another aspect of the present disclosure includes any of the foregoing aspects, and the first porosity and the second porosity are 10% to 40% of the open space volume to the total volume of the corresponding porous region.

[0010] Another aspect of the present disclosure includes any of the foregoing aspects, and the AM metal component includes a cooling channel therein.

[0011] One aspect of the present disclosure provides a turbine component, the turbine component comprising: an airfoil body having a pressure side, a suction side, and a trailing edge; an additively manufactured (AM) metal coupon comprising relatively inclined coupon sidewalls, a first porous region having a first porosity, and a second porous region having a second porosity different from the first porosity, the relatively inclined coupon sidewalls each forming an angle less than 90° with an outer surface of the AM metal coupon; and a braze material coupling the AM metal coupon in a coupon opening in the airfoil body, the braze 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, wherein the coupon opening comprises the relatively inclined coupon sidewalls mating with the coupon sidewalls.

[0012] Another aspect of the disclosure includes any of the foregoing aspects, and the AM metal coupon further includes an inclined end wall that is at an angle less than 90° to an outer surface of the AM metal coupon, and the coupon opening includes an inner wall that cooperates with the inclined end wall.

[0013] Another aspect of the disclosure includes any of the preceding aspects, and the relatively inclined coupon sidewalls extend from a pressure side to a suction side of the airfoil body.

[0014] Another aspect of the present disclosure includes any of the preceding aspects, and the relatively inclined coupon sidewalls extend from an upstream end of the metal coupon to a trailing edge of the airfoil body.

[0015] Another aspect of the disclosure includes any of the preceding aspects, and the relatively inclined coupon sidewalls extend from a pressure side to a suction side of the airfoil body.

[0016] 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.

[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 contains more brazing material therein than the second porous region.

[0018] 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 airfoil body, and the second porous region is adjacent to the at least a portion of the first porous region.

[0019] Another aspect of the present disclosure includes any of the foregoing aspects, and the first porosity and the second porosity are open space volumes of 2% to 50% of the total volume of the first porous region and the second porous region, respectively.

[0020] Another aspect of the present disclosure includes a method of coupling a metal coupon in a turbine component having an airfoil body having a pressure side, a suction side, and a trailing edge, the method comprising: additively manufacturing a metal coupon having relatively inclined coupon sidewalls, a first porous region having a first porosity, and a second porous region having a second porosity different from the first porosity, the relatively inclined coupon sidewalls each being at an angle less than 90° to an exterior surface of the metal coupon; positioning the metal coupon in a coupon opening in the airfoil body of the component, wherein the coupon opening includes the relatively inclined coupon sidewalls mating with the coupon sidewalls; and infiltrating the metal coupon with a brazing material to couple the metal coupon in the coupon opening in the airfoil 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.

[0021] Another aspect of the present disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a metal coupon having an inclined end wall, the inclined end wall forming an angle less than 90° with an outer surface of the metal coupon, and wherein the coupon opening includes an inner wall that cooperates with the inclined end wall.

[0022] Another aspect of the disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a metal coupon having relatively inclined coupon sidewalls extending from a pressure side to a suction side of an airfoil body.

[0023] Another aspect of the disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a metal coupon having relatively inclined coupon sidewalls extending from an upstream end of the metal coupon to a trailing edge of the airfoil body.

[0024] Another aspect of the present disclosure includes any of the foregoing aspects, and the additive manufacturing further includes forming relatively inclined coupon sidewalls extending from a pressure side to a suction side of the airfoil body.

[0025] Another aspect of the disclosure includes any of the foregoing aspects and further includes, prior to additive manufacturing: forming a coupon opening in the airfoil body configured to receive the metal coupon; and creating a model of the coupon opening, wherein the additive manufacturing includes manufacturing the metal coupon based on the model of the coupon opening.

[0026] 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.

[0027] 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

[0028] 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:

[0029] Figure 1 shows a schematic diagram of an exemplary turbine in the form of a gas turbine system and including components according to an embodiment of the present disclosure;

[0030] Figure 2 Shows that Figure 1 A cross-sectional view of an illustrative gas turbine assembly for use with a gas turbine system in and including a turbine component according to an embodiment of the present disclosure;

[0031] Figure 3 shows a perspective view of a turbine component in the form of a turbine rotating blade including a metal coupon according to an embodiment of the present disclosure;

[0032] Figure 4 shows a perspective view of a turbine component in the form of a turbine nozzle including a metal coupon according to an embodiment of the present disclosure;

[0033] 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;

[0034] 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;

[0035] Fig. 7A , Fig. 8A , Fig.9A , Fig. 10A and Fig.11A shows a perspective view of a metal coupon, and Figure 7B , Figure 8B , Fig. 9B , Fig. 10B and Fig. 11B shows an enlarged cross-sectional view of a corresponding metal coupon in a turbine component according to various embodiments of the present disclosure;

[0036] FIG. 12A to FIG. 12B shows a side view of a metal coupon in the trailing edge of an airfoil body of a turbine component according to an embodiment of the present disclosure;

[0037] Fig.13 An alternative inclined end wall for a metal coupon according to an embodiment of the present disclosure is shown. Figure 7B A cross-sectional view of line of sight 13-13 in FIG. 13; and

[0038] FIG. 14A to FIG. 14F A perspective view of a method according to various embodiments of the present disclosure is shown.

[0039] 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

[0040] 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 the exemplary application of the turbine. In doing so, if possible, common industry terms will be used and adopted in a manner consistent with their accepted meanings. 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 as a single part in this article may include multiple parts and be referenced as consisting of multiple parts in another context. Alternatively, an object that may be described as including multiple parts in this article may be referred to as a single part elsewhere.

[0041] 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.

[0042] 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.

[0043] 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 instances where the event occurs or the feature exists and instances where the event does not occur or the feature does not exist.

[0044] 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.

[0045] As indicated above, the present disclosure provides a turbine component, the turbine component including an airfoil body and an additively manufactured (AM) metal coupon having at least one inclined coupon sidewall at an angle less than 90° to the outer surface of the AM metal component. 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 the original manufacture or repair (i.e., it is an insertable portion). In certain embodiments, a pair of inclined coupon sidewalls are at an angle less than 90° to the outer surface of the AM metal component. As will be described, the inclined coupon sidewalls can take a variety of forms to help retain the metal coupon in the turbine component. The AM metal coupon also includes a first porous region having a first porosity and a second porous region having a second porosity different from the first porosity. The first porosity and the second porosity are open space volumes of 2% to 50% of the total volume of the first porous region and the second porous region, respectively. The turbine component includes an airfoil body having a pressure side, a suction side, and a trailing edge, and a coupon opening having an AM metal coupon therein. The coupon opening includes relatively inclined coupon sidewalls that cooperate with the coupon sidewalls, for example, to retain the metal coupon in the coupon opening. The brazing material couples the AM metal coupon in the coupon opening in the airfoil body and penetrates into at least one of the first porous region and the second porous region based on at least the characteristics of the first porosity and at least the characteristics of the second porosity. The method of coupling the metal coupon to the component can include additively manufacturing the metal coupon as noted, and positioning the metal coupon in the coupon opening in the airfoil body of the turbine component.

[0046] As noted, a metal coupon may be infiltrated with a brazing material to couple the metal coupon in a coupon opening in an airfoil body. The brazing material infiltrates 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. The porosity of the AM metal coupon is configured to direct the flow of one or more brazing materials in different ways to form physical properties different from those previously possible, 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 coupon does not suffer from the same disadvantages as the original part and / or cutout, and can be customized (with brazing material) to, for example, change: 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, such as by using less metal coupons of more expensive substrates. The inclined coupon sidewalls take advantage of operational loads (such as turbine aerodynamic loads from pressure differentials and drag) to hold the metal coupon within the component (such as a nozzle or blade trailing edge).

[0047] Figure 1 A schematic diagram of an exemplary industrial machine is shown, which may include components according to the teachings of the present disclosure. In this example, the machine includes a turbine 100 in the form of a gas 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, as well as 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.

[0048] 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.

[0049] 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 and a row 124 of axially adjacent rotating blades 132, the row of nozzles or buckets being coupled to the stationary housing 122 of the turbine 100. 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 blade rows 124 in the turbine assembly 110 include 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 (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 terms "component" or "turbine component" may collectively refer to the stationary 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.

[0050] Figure 3 and Figure 4 Illustrative turbine components, such as hot gas path components of a turbine, are shown in which the teachings of the present disclosure may be employed. 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 turbine assembly 110. 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 will be appreciated 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 an outboard tip 160, which may or may not include a tip shroud 136 ( Figure 2 ).

[0051] Figure 4 A perspective view of a stationary nozzle 126 of the type that may employ embodiments of the present disclosure is shown. 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 to a corresponding mounting member in the casing. The fixed nozzle 126 may also include a nozzle for positioning between the adjacent turbine rotor 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 it toward the turbine rotor blades 132 ( Figure 3 ) guides the flow of the working fluid. 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.

[0052] It should be appreciated that the bucket 132 or nozzle 126 may include internal cooling structures containing 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.

[0053] Embodiments of the present disclosure described herein may include aspects applicable to stationary nozzles 126 , turbine blades 132 , other forms of turbine components, and / or any other industrial component employing a coupon. Figure 3 and Figure 4 Also shown is an exemplary additively manufactured (AM) metal coupon 200 (hereinafter referred to as "metal coupon 200" or "AM metal coupon 200") in a turbine component 202 (hereinafter referred to as "component 202"). More specifically, the metal coupon 200 may be located in a coupon opening 204 in an airfoil 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 located 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 located in a coupon opening 204 in the leading edge 156, 182 of the blade 132 or the nozzle 126, respectively. However, it should be emphasized that the metal coupon 200 may be used in any coupon opening 204 in an airfoil body 206 of a component 202. The airfoil body 206 may include the pressure side outer wall 152, 178, suction side outer wall 154, 180 and trailing edge 158, 184 for a blade 132 or nozzle 126, respectively.

[0054] The additively manufactured metal coupon 200 including the sloped coupon sidewalls and / or sloped endwalls and one or more porous regions therein may be additively manufactured using any now known or later developed technique capable of forming the porous regions. 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 .

[0055] 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 coupon 200 using a plurality of melt beam sources 212, 214, 216, 218. In the illustrated example, the four melt beam sources may 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 as being implemented as a computer program code on a computer 236. To this extent, the computer 236 is shown to include 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 to communicate with an external I / O device / resource 250. Generally speaking, 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 component in computer 236, and I / O device 250 may include any device (e.g., 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 may include a single processing unit, or one or more processing units distributed across one or more locations (e.g., on a client and a server). Similarly, memory 238 and / or storage system 240 may reside at one or more physical locations. 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. 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, or the like.

[0056] 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.

[0057] 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, the latter being 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. As will be described, 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 regions. 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.

[0058] 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 illustrated, 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 respectively have a field including non-overlapping field regions in which each melting beam source may specifically melt metal powder, and may include at least one overlapping field region in which two or more sources may melt 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 FIG. 1 , melt beam source 212 is shown forming a layer of metal coupon 200 using melt beam 262 in one region, while melt beam source 214 is shown forming a layer of metal coupon 200 using melt beam 262′ in another region. 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 build platform 220 that is related to its actual position so as to provide individual position corrections (not shown) to ensure its individual 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 dimensions (e.g., shape and size in operation), power, and scanning speed.

[0059] Continue to refer Figure 5, the 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 the AM printer 232 can move to accommodate the addition of each new layer, for example, after each layer, the build platform 220 can be lowered and / or the chamber 260 and / or the coater 270 can be raised. The method can use different raw materials in the form of fine-grained metal powders, and the raw materials can be maintained in the chamber 260 accessible to the coater 270. In this case, the coupon 200 can be made of metal, which can include pure metals or alloys. In one example, the metal may 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) (for example, Haynes 282 available from Haynes International, Inc.) Other possibilities include, for example, René 108, CM 247LC, Mar M 247, and any precipitation hardenable (PH) nickel alloy.

[0060] 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 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 may be provided with or without the valve system 282. In the case of omitting the pump 280, the inert gas can only 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, for example, 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.

[0061] In operation, a build platform 220 having 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.

[0062] 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.

[0063] 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. 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 change in porosity 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 three-dimensional space that is empty (i.e., voids, gaps, empty spaces, and / or not filled with material) within a region or sub-region. As used herein, "different porosities" or "porosity differences" generally refer to any variety of characteristics, such as: open space volume as a percentage of 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 connecting coupon openings between pores 302 that 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 -11Cubic inches to 5.24×10 -7 In the drawings, the different porous regions or sub-regions are generally shown as continuous or in contact with each other, however, it should be emphasized that they can be isolated from each other in any manner, such as having solid areas between them. That is, a single metal coupon may include one or more isolated, non-contacting porous regions or sub-regions. Note that the terms "region" and / or "sub-region" can be used interchangeably to refer to changes in porosity. Due to differences in, for example, pore shape or pore connecting channels, it will be recognized that porosity differences may not be based solely on the percentage of open space volume to total volume. However, in cases where porosity differences are compared based on degree (e.g., higher or lower), the differences cited are only differences in volumetric properties, i.e., the percentage of open space volume to total volume.

[0064] A porous metal coupon 200 including different porous regions with different porosities (which may or may not include one or more porous sub-regions with different porosities) may be formed using an AM system 210 as described herein or any other metal additive manufacturing system or method capable of forming porous metal. In terms of operation of the AM system 210, the melting beam sources 212, 214, 216, 218 may be programmed to intermittently not sinter the metal, thereby leaving metal powder rather than solid material. The method may include overlapping the laser field regions 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, focus, and / or power may also be controlled to adjust the porosity. More specifically, additive manufacturing includes using an AM system 210 having one or more melting beam sources 212, 214, 216, 218 to fuse metal powder layers together, and adjusting parameters of the system to control the porosity of at least two porous regions. Adjusting the parameters may include at least one of the following: adjusting one or more melting beams 262, 262' (from sources 212, 214, 216, 218) Figure 5 ) of the melted areas; adjusting the system scan speed; or adjusting at least one of the melt beam spot size, focus, or power. When the unmelted metal powder is removed from the metal coupon 200, it leaves behind pores 302 with interconnecting channels therebetween and forming one or more porous regions in the metal coupon 200. In any case, the layered fabrication of the metal coupon 200 can 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.

[0065] FIG. 6A to FIG. 6D A schematic top view 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.6D A sample metal coupon 200 is shown having a first porosity of approximately 10% of the total volume of the sample with an open space volume (having a generally low amount of open space). Each porous region may have a porosity of 2% to 50% of the total volume of the porous region with an open space volume, i.e., 2% to 50% open space with other 50% to 98% solids. In other embodiments, each porosity may be 10% to 40% of the total volume of the porous region 300 with an open space volume, i.e., 10% to 40% open space with other 60% to 90% solids. In other embodiments, a porous region may be provided in the metal coupon 200 having a porous region in a range of less than 10%, in a range of less than 15%, in a range of less than 20%, in a range of less than 25%, in a range of less than 30%, in a range of less than 35%, in a range of less than 40%, in a range of less than 45%, in a range of 2% to 45%, in a range of 2% to 40%, in a range of 2% to 35%, in a range of 2% to 30%, in a range of 2% to 25%, in a range of 2% to 20%, in a range of 5% to 45%, in a range of 5% to 40%, in a range of 5% to 35%, in a range of 5% to 30%, in a range of 5% to 25%, in a range of 5% to 45%, in a range of 5% to 40%, in a range of 5% to 35%, in a range of 5% to 30%, in a range of 5% to 25%, or in a range of 5% to 25%. In some embodiments, the present invention relates to a porosity within a range of 5% to 20%, within a range of 10% to 45%, within a range of 10% to 40%, within a range of 10% to 35%, within a range of 10% to 30%, within a range of 10% to 25%, within a range of 10% to 20%, within a range of 15% to 45%, within a range of 15% to 40%, within a range of 15% to 35%, within a range of 15% to 30%, within a range of 15% to 25%, within a range of 15% to 20%, within a range of 10% to 50%, within a range of 20% to 50%, within a range of 25% to 50%, within a range of 30% to 50%, within a range of 35% to 50%, or within a range of 40% to 50%. Other ranges of porosity are also possible as will be described herein.

[0066] FIG. 7A to FIG. 7B , FIG. 8A to FIG. 8B , FIG. 9A to FIG. 9B , FIG. 10A to FIG. 10B as well as FIG. 11A to FIG. 11B A perspective view and a cross-sectional view of an exemplary additively manufactured (AM) metal coupon 200 are shown according to various embodiments. 7A to 11B , the figure labeled "A" shows a perspective view, and the figure labeled "B" shows a cross-sectional view along the line BB in the corresponding figure labeled "A", but the corresponding metal coupon 200 is located in the coupon opening 204 of the component 202. The figure labeled "B" also shows the metal coupon 200 and the component 202, wherein the turbine axis A extends into and out of the page of the figure. The metal coupon 200 includes an additively manufactured (AM) component 290, which has at least one inclined coupon sidewall that is less than 90° with the outer surface of the AM component 290 (i.e., the surface that will become the outer surface when the metal coupon 200 is located in the component 202). The AM metal component 290 also includes one or more porous regions 300 (having holes 302). FIG. 7A to FIG. 7B A metal coupon 200 is shown including a single porous region 300 having a first porosity (the entire coupon 200 having the first porosity); FIG. 8A to FIG. 8B A metal coupon 200 is shown comprising more than one (layered) porous regions 300A-300B of different porosities; FIG. 9A to FIG. 9B A metal coupon 200 is shown including one or more porous regions 300A-300B having different porosities and a solid region 304; FIG. 10A to FIG. 10B A metal coupon 200 is shown having a variable porosity region 300D located between (and possibly including at least a portion of) a first porous region 300A and a second porous region 300B having different porosities; and FIG. 11A to FIG. 11B A metal coupon 200 is shown including more than one (relatively) porous regions 300A-300B having different porosities. 7A to 11B In the figure, the metal sample block 200 is shown as having Figure 3 and Figure 4 126 is configured to be positioned in a coupon opening 204 in the trailing edge 158 or 184 of the blade 132 or nozzle 126, respectively. However, the coupon opening 204 may be located in the leading edge 156 or 182 of the blade 132 or nozzle 126, respectively. The metal coupon 200 may also be located in any tip (not shown) or airfoil section of the blade 132 or in the platform 170 (shown), 174 or airfoil section of the nozzle 126.

[0067] like FIG. 7A to FIG. 7B As shown in , the metal coupon 200 may include a first porous region 300 having a first porosity. FIG. 7A to FIG. 7B In FIG. 1 , the metal coupon 200 includes a single porous region 300 having a single first porosity. FIG. 7A to FIG. 7B In the embodiment, the entire metal sample block 200 has a first porosity. Therefore, each layer of the metal sample block 200 has the same porosity. FIG. 8A to FIG. 8B , FIG. 9A to FIG. 9B , FIG. 10A to FIG. 10B and FIG. 11A to FIG. 11B In FIG. 1 , the metal coupon 200 includes two porous regions 300A to 300B each having a different porosity. FIG. 8A to FIG. 8B In the embodiment, the two different porous regions 300A, 300B are a layered inner region and an outer region, one of which is closer to the inside of the metal coupon than the other, and FIG. 11A to FIG. 11B In the embodiment of the present invention, two different porous regions 300A, 300B are located in different sides (e.g., the upper side and the lower side as illustrated) of the metal coupon 200. The region within the layer of the metal coupon 200 defining the porous regions 300A to 300B may be formed to include pores 302. FIG. 9A to FIG. 9B In the embodiment, metal coupon 200 includes porous regions 300A-300B and solid region 304, each of which may have the same or different porosities (shown later). Here, the area within the layer of metal coupon 200 that defines regions 300A-300B may be formed to include pores 302, and the area within the layer of metal coupon 200 that defines solid region 304 may be formed without pores 302. FIG. 10A to FIG. 10B In the embodiment, the metal sample block 200 includes a variable porosity region 300D located between a first porous region 300A and a second porous region 300B having different porosities (and may include at least a portion of the first porous region and the second porous region). Here, the area within the layer of the metal sample block 200 defining the regions 300A to 300B or the variable porosity region 300D can be formed to include, for example, pores 302 of different sizes or numbers 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. 10A to FIG. 10B is shown as FIG. 8A to FIG. 8B As in the example, the variable porous region is located between the inner porous region 300A and the outer porous region 300B, but the variable porous region can also be applied to FIG. 11A to FIG. 11B. Each porous region 300 can have a porosity of 2% to 50% of the total volume of the porous region 300 (i.e., 2% to 50% of the open space and 50% to 98% of the other solids). In other embodiments, each porosity can be 10% to 40% of the total volume of the porous region 300, i.e., 10% to 40% of the open space and 60% to 90% of the other solids. Other ranges of porosity are also possible. For example, the porous region 300 can have any porosity described throughout the present disclosure.

[0068] The AM metal component 290 and the metal coupon 200 may include at least one inclined coupon sidewall 292 (and 294) each at an angle less than 90° to an outer surface 296 of the AM metal component 290. The inclined coupon sidewalls 292, 294 and outer surface 296 may be varied to provide different converging tapers that utilize operational loads from pressure differential and / or drag (such as turbine aerodynamic loads) to retain the metal coupon 200 within the component 202 (e.g., the nozzle 126 or the blade 132 trailing edge 158, 180).

[0069] In a first option, the inclined coupon sidewalls 292, 294 are angled less than 90° from the outer surface 296 of the AM metal component 290 to provide a first portion or side 326 of the component 202 (such as the airfoil pressure side outer wall 152, 178 ( Figure 3 to Figure 4 )) to a second portion or side 328 of the component 202 (such as the suction side outer wall 154, 180 ( Figure 3 to Figure 4 That is, the relatively inclined coupon sidewalls 292, 294 extend from the pressure side outer wall 152, 178 of the airfoil body 206 to the suction side outer wall 154, 180. (For clarity, Figure 7B , Figure 8B , Fig. 9B , Fig. 10B , Fig. 11B Only the sides 326, 328 are shown). Here, the inclined coupon sidewalls utilize operational loads (e.g., turbine aerodynamic loads from pressure differentials) to hold the metal coupon 200 within the component 202 (e.g., the nozzle 126 or the blade 132 trailing edge 158, 184, respectively). In this regard, FIG. 7A to FIG. 7B An AM metal component 290 is shown having a single inclined coupon sidewall 292, while FIG. 8A to FIG. 8B , FIG. 9A to FIG. 9B , FIG. 10A to FIG. 10B and FIG. 11A to FIG. 11BAn AM metal component 290 is shown having a pair of relatively inclined coupon sidewalls 292, 294. Each inclined coupon sidewall 292, 294 is at an angle α of less than 90° with an outer surface 296 of the AM metal component 290 (such as a first portion or side 326 of the component 202, such as the (concave pressure) side outer wall 152, 178 of the airfoil 150, 176) and / or a second portion or side 328 of the component 202 (such as the second (convex suction) side outer wall 154, 180 of the airfoil 150, 176). In contrast, FIG. 7A to FIG. 7B The non-inclined coupon sidewall 293 in the AM metal component 290 is at an angle of about 90° to the outer surface 296 of the AM metal component 290. The outer surface 296 can be the outer surface of the metal coupon 200 that does not intersect the coupon opening 204 in the component 202. For example, as depicted in the "B" figure, in this option, the outer surface 296 can be the upper surface, the lower surface, or both the upper surface and the lower surface of the metal coupon 200 while being located in the coupon opening 204 of the component 202. That is, the outer surface 296 is the outer surface of the metal coupon 200 when it is located in the component 202. With the pair of inclined coupon sidewalls 292, 294 at an angle α, the two walls form a converging profile from a first portion or side 326 of the component 202 (such as the (concave pressure) side outer wall 152, 178 of the airfoil 150, 176) to a second portion or side 328 of the component 202 (such as the second (convex suction) side outer wall 154, 180 of the airfoil 150, 176). That is, a converging taper is provided from the airfoil pressure side outer wall 152, 178 to the suction side outer wall 154, 180. In this regard, the width W1 of the metal coupon 200 at or near the side 326 (pressure side outer wall 152, 178) is greater than the width W2 at or near the side 328 (suction side outer wall 154, 180). Regardless of the number of inclined coupon block side walls, the coupon block opening 204 has mating inner walls 298 , 299 to match the coupon block inclined side walls 292 , 294 .

[0070] The converging taper of the inclined coupon sidewalls 292, 294 from the airfoil pressure side outer wall 152, 178 to the suction side outer wall 154, 180 may take a variety of forms. FIG. 8A to FIG. 8B In FIG. 1 , the inclined coupon side walls 292, 294 are partially inclined along the height of each coupon side wall 292, 294. The inner walls 298, 299 are similarly partially inclined along their height. FIG. 9A to FIG. 9B In the embodiment, the inclined coupon sidewalls 292, 294 are inclined along the entire height of each coupon sidewall 292, 294 and may have a slight convex curvature. The inner walls 298, 299 are similarly inclined along their entire height and have a slight concave curvature that matches the curvature of the connecting sidewalls 292, 294. FIG. 9A to FIG. 9BAny radius of curvature can be used in the embodiments as long as the inner walls 298, 299 retain the metal coupon 200 within these inner walls. FIG. 10A to FIG. 10B In FIG. 1 , the inclined coupon side walls 292, 294 are inclined along the entire height of each coupon side wall 292, 294. The inner walls 298, 299 are similarly inclined along their entire height. FIG. 8A to FIG. 8B , FIG. 9A to FIG. 9B and FIG. 10A to FIG. 10B In FIG. 1 , the inclined coupon sidewalls 292, 294 are inclined at the same angle α relative to the outer surface 296 of the metal coupon 200 along the entire height of each coupon sidewall 292, 294. The inner walls 298, 299 are similarly inclined along their entire height. However, matching angles on both sidewalls of the metal coupon are not required. FIG. 11A to FIG. 11B , the inclined coupon sidewalls 292, 294 are inclined along the entire height of each coupon sidewall 292, 294, but the coupon sidewall 292 is angled at an angle α1 relative to the outer surface 296, which is different from the angle α2 of the coupon sidewall 294, i.e., α1≠α2. The inner walls 298, 299 are similarly inclined along their entire heights, with these sidewalls having angles that match their intersecting coupon sidewalls 292, 294, respectively.

[0071] FIG. 12A to FIG. 12B A side view of a metal coupon 200 in a component 202 in the form of an airfoil 150, 176 having a trailing edge 158, 184 is shown. FIG. 12A to FIG. 12B The arrow A of the turbine axis A in FIG. 1 points to the turbine 100 ( Figure 1 ). In a second option, the angled coupon sidewalls 292, 294 are at an angle β greater than 90° with an outer surface 296 of the AM metal component 290 at the trailing edge 158, 184 (not the sides 326, 328) of the airfoil 150, 176. In this option, the outer surface 296 is the trailing edge 158, 184 (not the sides 326, 328) of the airfoil 150, 176. Fig. 12A A single inclined coupon sidewall 292 is shown, and Fig. 12BA pair of relatively inclined coupon sidewalls 292, 294 are shown. A converging taper is provided from the upstream end 308 of the metal coupon 200 to the outer surface 296 at the trailing edge 158, 184. The relatively inclined coupon sidewalls 292, 294 (two of which are used) extend from the upstream end 308 of the metal coupon 200 to the trailing edge 158, 184 of the airfoil body 206. In other words, the coupon inclined walls 292, 294 (surfaces or faces) running parallel to the turbine axis A (of the rotor 112) are configured to have a converging taper from front to rear. The width W3 at the outer surface 296 (trailing edge 158, 184) of the metal coupon 200 is less than the width W4 at the upstream end 308 of the metal coupon 200. The inclined coupon sidewalls utilize operational loads (e.g., turbine aerodynamic drag) to retain the metal coupon 200 within the component 202 (e.g., nozzle or blade trailing edge). Where two coupon block sloping side walls 292, 294 are used, the angle β may be the same or may be different for both coupon block sloping side walls. In any case, the coupon block opening 204 has mating inner walls 298, 299 to match the coupon block sloping side walls 292, 294 in the second option.

[0072] As is apparent from the figures, both options for coupon sloped sidewalls 292 , 294 can be used together to exploit operational loads in terms of both turbine aerodynamic loads from pressure differential and drag to retain metal coupon 200 within component 202 , such as a nozzle or blade trailing edge.

[0073] Fig.13 Shown along Figure 7B A cross-sectional view of line 13-13 in FIG. Fig.13 As shown in , the AM metal component 290 may also include an inclined end wall 340 that is at an angle γ less than 90° to the outer surface 296 of the AM metal component 290 (metal coupon 200). The coupon opening 204 has a mating inner wall 342 to match the coupon inclined end wall 340. The inclined end wall 340 and the mating inner wall 342 of the coupon opening 204 can be further used to guide the AM metal component 290 (metal coupon 200) into a desired position. The inclined end wall 340 and the mating inner wall 342 of the coupon opening 204 also utilize operational loads in terms of two turbine aerodynamic loads from pressure differential and drag to keep the metal coupon 200 within the component 202 (such as a nozzle or blade trailing edge). Although in Fig. 7A The embodiment of FIG. 1 shows the inclined end wall 340 and the cooperating inner wall 342 of the sample block opening 204, but the inclined end wall and the cooperating inner wall are applicable to any embodiment herein. Fig.13As shown in , the inclined end wall 340 can make the first length L1 of the AM metal component 290 (metal coupon 200) on the first side 326 (e.g., the pressure side) longer than the second length L2 of the AM metal component 290 (metal coupon 200) on the second side 328 (e.g., the suction side).

[0074] refer to Figure 3 , Figure 4 , Figure 5 , 7A to 11B Figure 12 Fig.13 and FIG. 14A to FIG. 14E , embodiments of a method according to the present disclosure will now be described. The method may include coupling a metal coupon in a turbine component 202 . FIG. 14A to FIG. 14F A perspective view of a method according to an embodiment of the present disclosure is shown.

[0075] Fig.14A A coupon opening 204 is shown formed in an airfoil body 206 of a component 202. The coupon opening 204 is configured to receive a metal coupon 200. The coupon opening 204 may have any desired shape. In certain applications, the coupon opening 204 is formed by removing a damaged portion of the airfoil body 206 of the component 202, but the coupon opening 204 may also be in the original form of the component 202, such as in 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.14A Also shown is the creation of a model of the coupon opening 204. The model creation may include using any now known or later developed three-dimensional scanner (not shown, see arrows) to scan and create a digital representation of the coupon opening 204 relative to the airfoil 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.

[0076] Figure 5 , FIG. 8A to FIG. 11B 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 to FIG. 7B Also shown is a metal coupon 200 formed to have a single porosity (not solid); and FIG. 10A to FIG. 10BAlso shown is a metal coupon 200 formed with a variable porosity region 300D, which is located between the first porous region 300A and the second porous region 300B and may include portions of the first porous region and the second porous region. The variable porosity region 300D may include a gradually changing porosity 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 may 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. The additive manufacturing may include any AM method described herein to manufacture a porous metal coupon 200 (or a dense or solid region). The additive manufacturing may include selectively forming a porous region 300 among the solid regions of the metal coupon 200 by controlling an AM printer 232. The additive manufacturing can include manufacturing the metal coupon 200 to approximately 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 has no or minimal additional processing (e.g., machining) at a specified stage of the manufacturing method within the desired manufacturing tolerances. Some additional texturing or polishing of the outer surface may be required. It should be recognized that additional coatings can be applied once the metal coupon 200 is located in the component. When formed into a near net shape, the metal coupon 200 can also have a surface required to couple the metal coupon 200 in the coupon opening 204 after manufacturing that is very close to the airfoil body 206 when positioned 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 coupons 200 accommodates larger joint gap size variations compared to solid coupons having narrow gaps for the braze material because the porous regions provide improved gripping and retention of the braze material despite the larger gap.

[0077] For the tilted specimen block sidewall option, 7A to 11B As shown in , the additive manufacturing may also include additive manufacturing, including forming a metal coupon 200 having relatively inclined coupon sidewalls 292, 294 extending from the pressure side outer wall 152, 178 to the suction side outer wall 154, 180 of the airfoil body 206. Additionally or alternatively, as FIG. 12A to FIG. 12BAs shown in , the additive manufacturing may also include additive manufacturing, including forming a metal coupon 200 having relatively inclined coupon sidewalls 292, 294 extending from the upstream end 308 of the metal coupon 200 to the trailing edge 158, 184 of the airfoil body 206. As another option, as Fig.13 As shown in , the additive manufacturing may also include forming a metal coupon 200 having an inclined end wall 340 that forms an angle γ less than 90° with an outer surface of the AM metal coupon, and wherein the coupon opening includes an inner wall that cooperates with the inclined end wall.

[0078] Although the metal coupon 200 is shown as FIG. 14B to FIG. 14C In Figure 7B Although additively manufactured as in the embodiments described herein, the metal coupon may take any of the forms described throughout this disclosure.

[0079] According to an embodiment of the present disclosure, the porosity of one or more porous regions 300 in the metal coupon 200 is controlled (ie, customized) to provide a porous region 300 having a porous structure. Figure 3 , Figure 4 as well as Figure 7B , Figure 8B , Fig. 9B , Fig. 10B and Fig. 11B 204 in the airfoil body 206 of the component 202 as shown in FIG. 200. The flow of braze material in the metal coupon 200 is controlled during a subsequent brazing process in which the metal coupon 200 is coupled to the coupon opening 204 in the airfoil body 206 of the component 202. Each porous region 300 can be customized with respect 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 direct the braze material as desired. For example, in FIG. 7A to FIG. 7B In the embodiment, the entire metal sample block 200 includes the first porous region 300, so the brazing material will be evenly distributed in the metal sample block. FIG. 8A to FIG. 8B In the embodiment, the metal sample block 200 includes a porous region 300A near the edge 306 of the metal sample block 200 (in which the metal sample block will contact the sample block opening 204 ( Figure 3 to Figure 4) connection) and a different porous region 300B having a different porosity 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, thereby producing different physical properties of the metal coupon 200 in different regions thereof. More specifically, any number of porous regions 300 can be used to customize (shape) at least one physical property of 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 can have a higher porosity in one region 300 compared to other solid regions of the metal coupon 200 to guide more brazing material in the metal coupon by capillary action, thereby controlling at least one physical property of the component 202. In another embodiment, the metal coupon 200 may have a lower porosity in one region 300 compared to other solid regions of the metal coupon 200 to direct less braze material in the metal coupon by capillary action, 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 result in the desired braze material flow and penetration.

[0080] In certain embodiments, the additive manufacturing may also include forming any type of improvements to the component 202 in the metal coupon 200, including, for example, structures that did not previously exist in the component 202. The component 202 may be an original component that needs improvement or a component that includes removed or damaged portions. For example, Fig.9A As shown in , the additive manufacturing can optionally include forming a cooling channel 320 in the metal coupon 200. The cooling channel 320 can extend in the metal coupon 200 in any manner, such as extending in a serpentine path in the metal coupon or extending through an outer surface 322 of the metal coupon 200. Any advantageous internal structural changes can be made in the metal coupon 200. The metal coupon 200 can optionally be subjected to any now known or later developed post-additive manufacturing finishing process, such as grinding to smooth its surface. However, advantageously, the teachings of the present disclosure can eliminate the need for other finishing steps (such as shot peening, heat treatment, hot isostatic pressing (HIP), etc.) that are typically used to address residual stresses present in the material after additive manufacturing.

[0081] Fig. 14B and Fig. 14CThe metal coupon 200 is shown positioned in a coupon opening 204 in a body 206 (e.g., an airfoil) of a component 202. The metal coupon 200 may be positioned in the opening 204 in the body 206 in any now known or later developed manner, such as manually via a press fit or a slip fit. If necessary, the metal coupon 200 may be held in place in any desired manner, such as adhesives, clamps, nickel-chrome tack welds, ball tack welds, resistance welds, fusion tack welds, etc. The angled coupon sidewalls 292, 294 and / or the angled end wall 340 may be used to position the metal coupon 200 in the coupon opening 204 of the airfoil body 206 of the component 202.

[0082] FIG. 14D to FIG. 14E The brazing material 310 is shown to infiltrate the metal coupon 200 to couple the metal coupon in the coupon opening 204 in the airfoil 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 table below along with other brazing material formulations:

[0083]

[0084] 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.14D ) and applying heat ( Fig.14E ), thereby causing the brazing material to flow into, through, and around the metal sample block 200 by capillary action.

[0085] The infiltration injects the brazing material 310 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. 10A to FIG. 10B ), the penetration includes causing the brazing material 310 to travel through and penetrate the first porous region 300A based on the characteristics of the first porosity, travel through and penetrate the variable porosity region 300D based on the characteristics of the variable porosity region 300D (e.g., a porosity gradient, stepped porosity, etc.), and travel through and penetrate the second porous region 300B based on the characteristics of the second porosity.

[0086] The different porosities of the porous regions 300A, 300B and possibly the variable porosity region 300D produce different flows and penetrations of the brazing material 310. Due to the brazing process, the first porous region 300A and the second porous region 300B having the brazing material 310 therein have at least one different physical property. Where a variable porosity region 300D is present, the variable porosity region may have different physical properties than the first porous region 300A and the second porous region 300B. Therefore, due to the brazing process, the first porous region 300A and the second porous region 300B (and possibly the variable porosity region 300D) having the brazing material 310 therein in the component 202 have at least one different physical property. For example, more brazing materials 310 can produce stronger joint adhesive bond strength, higher ductility, higher thermal conductivity or conductivity or higher oxidation resistance, and less brazing materials 310 can produce less surface roughness, less hardness, lower joint adhesive bond strength, lower ductility, lower thermal conductivity or conductivity or lower oxidation resistance. In any case, the amount of controlling brazing materials and the porosity of different porous regions allow to control the physical properties of the final product. In one example, the first porosity of the first porous region 300A can be higher (that is, density is lower) than the second porosity of the second porous region 300B. In this case, infiltration includes utilizing the brazing material 310 more than the second porous region 300B to infiltrate the first porous region 300A. Depending on the braze material 310 used, different porosities allow for customization of at least one physical property of the component 202, such as, among other factors: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or quality. In addition, compared to conventional narrow gap fill brazing methods, and due to the tight manufacturing tolerances required for narrow gap brazing, multiple flow paths for the braze material 310 using the porous region 300 can reduce the likelihood of lack of fill and / or voids along the brazed joint. Therefore, despite using a metal coupon 200 with a porous region 300 in the component 202, the component can still be at least 98% solid.

[0087] 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 in the component 202 and the region of the component 202. For example, referring to FIGS. Fig. 11B , a first brazing material 310A may be used on a first portion or side 326 of the component 202, and another brazing material 310B different from the first brazing 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. 9B, 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.

[0088] Other embodiments of methods according to the present disclosure may include forming only the metal coupon 200 for the component 202. In this case, Fig.14A As shown in , the method includes creating a model of a coupon opening 204 in an airfoil body 206 of a component 202, and additively manufacturing a metal coupon 200 to at least closely fit the coupon opening 204, for example, in a near net shape of the coupon opening 204. As described herein and in FIG. 8A to FIG. 8B , FIG. 9A to FIG. 9B , FIG. 10A to FIG. 10B , FIG. 11A to FIG. 11B As shown in , the metal coupon 200 may include at least one inclined sidewall 292, 294 and / or an inclined end wall 340, 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 form different physical properties.

[0089] Fig.14F Exemplary optional finishing steps for component 202 are shown, such as but not limited to machining to smooth the outer surface and remove excess brazing material. As noted, the teachings of the present disclosure eliminate the need for other finishing steps such as shot peening, heat treatment, hot isostatic pressing (HIP), etc.

[0090] Figure 3 , Figure 4 , Figure 7B , Figure 8B , Fig. 9B , Fig. 10B , Fig. 11B , FIG. 12A to FIG. 12B and Fig.13 An embodiment of a turbine component 202 according to an embodiment of the present disclosure is shown. As noted, Figure 7B , Figure 8B , Fig. 9B , Fig. 10B , Fig. 11BAn enlarged cross-sectional view of a metal coupon 200 on a coupon opening 204 of an airfoil body 206 of a component 202 is shown. Figure 7B A component 202 is shown including a metal coupon 200 having a single porous region 300, Figure 8B A component 202 is shown including a metal coupon 200 having two or more porous regions 300A, 300B, Fig. 9B The invention shows a structure including two or more porous regions 300A, 300B and a solid region 304 ( Fig.9A ) of a metal sample block 200, Fig. 10B 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. 11B A component 202 is shown including a metal coupon 200 having two porous regions 300A, 300B and different brazing materials 310A, 310B located on different sides 326, 328 of the metal coupon 200. The component 202 includes an airfoil body 206 having a pressure side outer wall 152, 178, a suction side outer wall 154, 180, and a trailing edge 158, 184. In the example used herein, the airfoil 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 Figure 3 and Figure 4 132 and the nozzle 126, respectively, but the metal coupon 200 may be located in any portion of the airfoil body 206 of the component 202. The additively manufactured (AM) metal coupon 200 may include any of the options of relatively inclined coupon sidewalls 292, 294, each at an angle less than 90° to its outer surface 296, as described herein. FIG. 8A to FIG. 11B As described, the AM metal coupon 200 also includes 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 brazing material 310 couples the metal coupon 200 in the coupon opening 204 in the airfoil body 206. Figure 7B As shown in FIG. 3 , the brazing material 310 includes a first section 330 that penetrates into the first porous region 300A based at least on the characteristics of the first porosity. Figure 8B , Fig. 9B , Fig. 10B and Fig. 11BAs shown in , the metal sample block 200 also includes a second porous region 300B having a second porosity different from the first porosity. The first porosity may 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 airfoil body 206 may have a third porosity different from one or both of the first porosity and the second porosity. For example, the airfoil body 206 may have a third porosity that is denser than both the first porosity and the second porosity, for example, the airfoil body may be 100% solid. Optionally, the metal sample block 200 may include a (in) 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. 10B The variable porosity region 300D (shown by a dashed box in FIG. 1 ) may be a variable porosity region 300D. The variable porosity region 300D may gradually change porosity between a first porosity and a second porosity, for example, in a stepwise or incremental manner. Fig. 10B In FIG. 2 , different porous regions 300A, 300B are layered in the metal coupon 200, with one porous region inside another porous region. Fig. 11B In FIG. 2 , different porous regions 300A, 300B are located on opposite sides of the metal coupon 200 .

[0091] exist Fig. 10B and Fig. 11B , the brazing material 310B includes a second section 332 that penetrates into the second porous region 300B based at least on the characteristics of the second porosity. The "at least one characteristic" of the porosity indicates that the porosity can produce different penetration characteristics, such as brazing material volume, porosity intra-pattern, 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 (ie, less dense) than the second porous region 300B, and the first porous region 300A may contain more brazing material 310 therein than the second porous region 300B. Fig. 10B In another example shown in , the first porous region 300A is located in at least a portion of the edge 306 of the metal coupon 200 that is configured for bonding to the airfoil body 206, while the second porous region 300B is closer to the interior of the metal coupon 200. Fig. 11BIn another example shown in FIG. 1 , a first porous region 300A is located in one side 326 of the metal coupon 200 and a second porous region 300B is located in an 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. 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. 10B , 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 airfoil body 206, or the arrangement 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.

[0092] exist Fig. 11B In the embodiment, the brazing material 310B further includes a second section 332 that penetrates into the second porous region 300B based at least on the characteristics of the second porosity. Fig. 11B In the example, 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. Fig. 11B, this arrangement can advantageously place more braze material 310 on the side 326 near the braze joint 334 to enhance the joint adhesive bond strength of the metal coupon 200 in the coupon opening 204 in the airfoil body 206, or the arrangement 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.

[0093] As noted, the metal coupon 200 may have a near net shape of the coupon opening 204 in the airfoil body 206 of the component 202. Fig. 14C As shown in FIG, 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.

[0094] Although specific locations of the different porous regions 300 have been shown 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 .

[0095] like Figure 1 to Figure 2 As shown, 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. Component 202 may take the form of a turbine stationary nozzle 126, a turbine rotating blade 132, or other component of turbine 100. Metal coupon 200 may be used in a newly manufactured component or in a component that needs repair or improvement. It should be noted that although the method is shown as being applied to an airfoil, component 202 may be any industrial component.

[0096] 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 the cost-effective production of metal coupons with custom-fitted 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 area can also provide a welding / fusion 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 multiple flow paths for the brazing material using porous areas can also reduce the possibility of lack of filling and / or voids along the brazing joint. The porous area can be formed to have a porosity difference across the metal coupon to allow highly customized brazing material flow. Compared with a machined solid coupon with a narrow gap for the brazing material, the porous area also adapts to larger 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 provide improved physical properties compared to current technologies such as pre-sintered preforms (PSPs). Angled coupon sidewalls and / or angled endwalls utilize operational loads (e.g., turbine aerodynamic loads from pressure differential and drag) to hold the metal coupon within a component (e.g., a nozzle or blade trailing edge).

[0097] 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.

[0098] 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 metal sample block (200), comprising: An additively manufactured (AM) metal component (290), the additively manufactured (AM) metal component having: at least one inclined coupon sidewall (292, 294), the at least one inclined coupon sidewall being at an angle less than 90° to an outer surface (296) of the AM metal component (290); a first porous region (300A), the first porous region having a first porosity; as well as a second porous region (300B), the second porous region having a second porosity different from the first porosity, The first porosity and the second porosity are respectively 2% to 50% of the open space volume in the total volume of the first porous region (300A) and the second porous region (300B).

2. The metal coupon (200) of claim 1, wherein the AM metal component (290) includes a variable porosity region (300D) located between the first porous region (300A) and the second porous region (300B).

3. The metal coupon (200) of claim 1, wherein the AM metal component (290) further comprises an inclined end wall (340) that is at an angle less than 90° to the outer surface (296) of the AM metal component (290).

4. The metal coupon (200) according to claim 1, wherein the first porosity and the second porosity are open space volumes that account for 10% to 40% of the total volume of the corresponding porous region (300A, 300B).

5. The metal coupon (200) of claim 1, wherein the at least one sloped coupon sidewall (292, 294) comprises a pair of oppositely sloped coupon sidewalls (292, 294).

6. A turbine component (202), comprising: an airfoil body (206) having a pressure side (152, 178), a suction side (154, 180), and a trailing edge (158, 184); An additively manufactured (AM) metal coupon (200) comprising relatively inclined coupon sidewalls (292, 294), 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 relatively inclined coupon sidewalls each forming an angle less than 90° with an outer surface (296) of the AM metal coupon (200); as well as a brazing material (310) coupling the AM metal coupon (200) in a coupon opening (204) in the airfoil body (206), the brazing material (310) infiltrating 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, The sample block opening (204) includes relatively inclined sample block side walls (292, 294) that cooperate with the sample block side walls.

7. The turbine component (202) of claim 6, wherein the AM metal coupon (200) further comprises an inclined end wall (340) that is at an angle less than 90° to the outer surface (296) of the AM metal coupon (200), and the coupon opening (204) comprises an inner wall (342) that cooperates with the inclined end wall (340).

8. The turbine component (202) of claim 6, wherein the relatively inclined coupon sidewalls (292, 294) extend from the pressure side (152, 178) to the suction side (154, 180) of the airfoil body (206).

9. The turbine component (202) of claim 6, wherein the relatively inclined coupon sidewalls (292, 294) extend from an upstream end (308) of the metal coupon (200) to the trailing edge (158, 184) of the airfoil body (206).

10. The turbine component (202) of claim 9, wherein the relatively inclined coupon sidewalls (292, 294) extend from the pressure side (152, 178) to the suction side (154, 180) of the airfoil body (206).

11. The turbine component (202) of claim 6, wherein the AM metal coupon (200) includes a variable porosity region (300D) located between the first porous region (300A) and the second porous region (300B) and including the first porous region and the second porous region.

12. The turbine component (202) of claim 6, wherein the first porosity is higher than the second porosity, and the first porous region (300A) contains more brazing material (310) in the first porous region than the second porous region (300B).

13. The turbine component (202) of claim 6, wherein the first porous region (300A) is located in at least a portion of an edge (306) of the metal coupon (200) configured to be joined to the airfoil body (206), and the second porous region (300B) is adjacent to the at least a portion of the first porous region (300A).

14. The turbine component (202) of claim 6, wherein the first porosity and the second porosity are open space volumes of 2% to 50% of the total volume of the first porous region (300A) and the second porous region (300B), respectively.

15. A method of coupling a metal coupon (200) in a turbine component (202) having an airfoil body (206) having a pressure side (152, 178), a suction side (154, 180), and a trailing edge (158, 184), the method comprising: additively manufacturing the metal coupon (200), the metal coupon comprising relatively inclined coupon sidewalls (292, 294), 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 relatively inclined coupon sidewalls each forming an angle less than 90° with an outer surface (296) of the metal coupon (200); positioning the metal coupon (200) in a coupon opening (204) in an airfoil body (206) of the component (202), wherein the coupon opening (204) includes relatively inclined coupon sidewalls (292, 294) that mate with the coupon sidewalls; and The metal coupon (200) is infiltrated with a brazing material (310) to couple the metal coupon (200) to the coupon opening (204) in the airfoil 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.

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