Method for providing brazing reservoir in metal part or sample block thereof

Abstract

The present disclosure relates to a method of providing a braze reservoir in a metal part or a sample block thereof. A metal sample block (200) for insertion into a component (202) includes an additive manufactured (AM) (210) metal component that includes a braze reservoir (292).

Description

Technical Field

[0001] The present disclosure relates generally to component repair and, more particularly, to component repair using a metal coupon with a braze reservoir or by using a braze reservoir in a component. Background Art

[0002] Industrial components sometimes need repair. For example, hot gas path components used in turbines to direct working fluid to create energy may need repair. Hot gas path components can take various forms, such as turbine rotor blades or stationary vanes, which include airfoils that direct working fluid to create energy. The rotor blades are coupled to the turbine rotor and are used to turn the turbine rotor, and the stationary vanes are coupled to the casing of the turbine to direct the working fluid toward the rotor 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 blade. For example, a portion of the leading edge of a turbine blade can be removed, leaving a cutout in the blade, and a new section (referred to herein as a "coupon") can be connected in the cutout. The coupon is additively manufactured to have a shape that at least roughly matches the shape of the cutout. The coupon can replace a worn section of a used turbine blade or be added as part of a new turbine blade. The coupon can replace only the internal cooling structure of the turbine blade, or additional or improved cooling structures that are not provided in the original turbine blade can be advantageously provided, for example, near the wall cooling channel.

[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 has some shortcomings identical with the original parts and / or the incision, and does not improve general performance characteristics, such as overall strength, stress resistance / strain resistance, ductility, wear resistance, thermal conductivity or electrical conductivity and / or quality degradation. 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 related to 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 also do not allow to reduce the high material cost of the replacement sample block. In addition, current brazing process only introduces brazing material from the outside of metal sample block and / or parts, thereby limits the ability of brazing material being guided to sample block and / or parts interior, for example to repair internal damage, ensure brazing penetration and / or otherwise improve brazing performance. Summary of the invention

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

[0006] Another aspect of the present disclosure includes a method that includes: additive manufacturing a metal specimen block in a specimen block opening of a body for an insert component, the metal specimen block including an additive manufacturing (AM) metal component having a brazing reservoir, the brazing reservoir including: a first cavity defined in the AM metal component; a second conduit defined in the AM metal component and fluidly coupling the first cavity to an outer surface of the AM metal component; a first conduit defined in the AM metal component and fluidly coupling the first cavity to a brazing region; and a blocking member extending across the first conduit to block fluid communication between the first cavity and the brazing region; inserting a first brazing material into the first cavity through the second conduit; separating the second conduit from the exterior of the AM metal component; positioning the metal specimen block in the specimen block opening; and heating the AM metal component to a predetermined temperature that exceeds the melting temperature of the first brazing material, thereby liquefying the first brazing material and opening the blocking member, and the liquefied first brazing material flowing through the first conduit to penetrate the brazing region.

[0007] Another aspect of the present disclosure includes any of the foregoing aspects, and the AM metal component includes a porous region having porosity, and the method further includes applying a second brazing material different from the first brazing material to at least the AM metal component, and wherein the heating causes the second brazing material to penetrate into at least the porous region based at least on the characteristics of the porosity of the porous region to couple the AM metal component in the specimen block opening.

[0008] Another aspect of the present disclosure includes any of the foregoing aspects, and the blocking member includes a eutectic mixture of the metal material of the AM metal component and the first brazing material, wherein the predetermined temperature exceeds the melting temperature of the first brazing material.

[0009] Another aspect of the present disclosure includes any of the foregoing aspects, and the additive manufacturing further includes additive manufacturing a second cavity between the first cavity and the brazing region in the AM metal component and the first conduit, and filling the second cavity with a second brazing material, wherein the liquefied first brazing material flows through the first conduit and liquefies the second brazing material, and wherein the liquefied first brazing material and the liquefied second brazing material penetrate the brazing region.

[0010] Another aspect of the present disclosure includes any of the foregoing aspects, and the brazing region includes at least one of the following: a porous region in the AM metal component, a contact interface between the metal specimen block and the specimen block opening in the body of the component in which the metal specimen block is located, and a portion or outer surface of the body of the component in which the metal specimen block is located.

[0011] Another aspect of the present disclosure includes any of the foregoing aspects, and the porous region has a variable porosity, wherein two or more sub-porous regions have different porosities.

[0012] Another aspect of the present disclosure includes any of the foregoing aspects, and the method further includes removing the brazing reservoir from the metal specimen block after the heating.

[0013] Another aspect of the present disclosure includes a method that includes: additive manufacturing a body of a component, the body including a brazing reservoir that includes: a first cavity defined in the body; a second conduit defined in the body and fluidly coupling the first cavity to an outer surface of the body; a first conduit defined in the body and fluidly coupling the first cavity to a brazing region; and a blocking member that extends across the first conduit to block fluid communication between the first cavity and the brazing region; inserting a first brazing material into the first cavity through the second conduit; isolating the second conduit from the exterior of the body; and heating the body to a predetermined temperature that exceeds the melting temperature of the first brazing material, such that the first brazing material liquefies and the blocking member opens, and the liquefied first brazing material flows through the first conduit to penetrate the brazing region.

[0014] Another aspect of the present disclosure includes any of the foregoing aspects, and the blocking member includes a eutectic mixture of the metal material of the body and the first brazing material, wherein the predetermined temperature exceeds the melting temperature of the first brazing material.

[0015] Another aspect of the present disclosure includes any of the foregoing aspects, and the additive manufacturing further includes additive manufacturing a second cavity between the first cavity and the brazing region in the body and in the first conduit, and filling the second cavity with a second brazing material, wherein the liquefied first brazing material flows through the first conduit and liquefies the second brazing material, and wherein the liquefied first brazing material and the liquefied second brazing material penetrate the brazing region.

[0016] Another aspect of the present disclosure includes any one of the foregoing aspects, and the brazing region includes at least one of the following: a porous region in the body, a contact interface between the body and a metal specimen block in a specimen block opening in the body, at least one of a portion of the body and an outer surface, and a damaged region in the body.

[0017] Another aspect of the present disclosure includes any one of the foregoing aspects, and the porous region has a variable porosity, wherein two or more porous sub-regions have different porosities.

[0018] Another aspect of the present disclosure includes any one of the foregoing aspects, and the method further includes removing the brazing reservoir from the body after the heating.

[0019] Another aspect of the present disclosure includes any one of the foregoing aspects, and the heating occurs during use of the component.

[0020] Two or more aspects described in the present disclosure (including those described in this summary section) can be combined to form specific embodiments not specifically described herein. That is, all embodiments described herein can be combined with each other.

[0021] Details of one or more specific embodiments are set forth in the following drawings and description. Other features, objects, and advantages will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and other features of the present disclosure will be more readily understood from the following detailed description of the various aspects of the present disclosure in connection with the drawings depicting the embodiments of the present disclosure, in which:

[0023] Figure 1 A schematic diagram of an exemplary industrial machine in the form of a gas turbine system and including components according to an embodiment of the present disclosure is shown;

[0024] Figure 2 Is shown in connection with Figure 1 A cross-sectional view of an exemplary gas turbine assembly that can be used with the gas turbine system in and including components according to an embodiment of the present disclosure is shown;

[0025] Figure 3 A perspective view of a component in the form of a turbine rotating blade including a metal specimen block according to an embodiment of the present disclosure is shown;

[0026] Figure 4 A perspective view of a component in the form of a turbine nozzle including a metal specimen block according to an embodiment of the present disclosure is shown;

[0027] Figure 5A schematic block diagram of an exemplary additive manufacturing system for additive manufacturing of a metal specimen block according to an embodiment of the present disclosure is shown;

[0028] Figures 6A to 6D A top view of a sample metal specimen block including a porous region having different porosities according to an embodiment of the present disclosure is shown;

[0029] Figures 7A to 7D A cross-sectional view of a brazing reservoir in a body of a metal specimen block or component according to various embodiments of the present disclosure is shown;

[0030] Figures 8A to 8E A perspective view of a metal specimen block including a brazing reservoir according to an embodiment of the present disclosure is shown;

[0031] Figures 9A to 9G A perspective view or a cross-sectional view of a method according to various embodiments of the present disclosure is shown;

[0032] Figures 10A to 10E An enlarged cross-sectional view of a metal specimen block in an opening in a body of a component according to an embodiment of the present disclosure is shown; and

[0033] Figure 11 A perspective view of a component including a brazing reservoir according to an embodiment of the present disclosure is shown.

[0034] 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 should not therefore be considered as limiting the scope of the present disclosure. In the drawings, like numbers represent like elements between the drawings. Detailed Description

[0035] First, in order to clearly describe the present disclosure, when referring to and describing relevant machine components within an exemplary application of a turbine, it will be necessary to select certain terms. 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. Those of ordinary skill in the art will understand that several different or overlapping terms may typically be used to refer to a particular component. An object that may be described herein as a single part may include multiple components and be referred to in another context as being composed of multiple components. Alternatively, an object that may be described herein as including multiple components may be referred to elsewhere as a single part.

[0036] In addition, several descriptive terms may be regularly used herein, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise specified, these terms and their definitions are as follows. As used herein, "downstream" and "upstream" are terms indicating directions relative to the direction of fluid flow, such as the working fluid passing through a turbine, or for example the air flow through a burner or the 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, where "front" refers to the front end or compressor end of the turbine, and "rear" refers to the rear end or turbine end of the turbine.

[0037] In addition, several descriptive terms may be regularly used 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.

[0038] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the disclosure. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that when used in the specification, the terms "comprises" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. "Optional" or "optionally" means that the subsequent described event may or may not occur, or the subsequent described feature may or may not be present, and the description includes instances where the event occurs or the feature is present and instances where the event does not occur or the feature is not present.

[0039] When an element or layer is said to be "on another element or layer", "bonded 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 can be directly on, bonded to, connected to, coupled to, or mounted to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is said to be "directly on another element or layer", "directly bonded to another element or layer", "directly connected to another element or layer", or "directly coupled to another element or layer", no intervening elements or layers are present. Other words used to describe the relationship 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 "coupled" and "mounted" are used interchangeably herein.

[0040] As indicated above, the present disclosure provides a metal specimen block for insertion into a component. As used herein, a "specimen block" can include any portion located in a specimen block opening in the body of a component as part of the original manufacture of the component or, for example, as part of repairing the component after a damaged portion has been removed. The metal specimen block includes an additive manufacturing (AM) metal member that includes a brazing reservoir. The brazing reservoir includes: a first chamber located in the AM metal member; a second conduit fluidly coupling the first chamber to an outer surface of the AM metal member; a first conduit fluidly coupling the first chamber to a brazing area; a blocking member that blocks fluid communication through the first conduit between the first chamber and the brazing area; a brazing material located in the first chamber; and a sealing member that separates the second conduit from the exterior of the AM metal member. In another embodiment, a component can include a body that includes a brazing reservoir similar to the brazing reservoir just described. In any case, the brazing reservoir is thermally triggered by the metal specimen block and / or the component body reaching a predetermined temperature above the melting temperature of the brazing material, which may open the blocking member by pressure generated by the predetermined temperature, such as melting, dissolving the blocking member, or rupturing the blocking member. The brazing area that receives the liquefied brazing material can take various forms, such as but not limited to: a porous area in the AM metal member of the metal specimen block, an interface between the metal specimen block and the body of the component, or a crack in the component body. The use of a porous area in the metal specimen block allows for customization of the brazing process and the resulting structure and can also reduce material costs. In the case of repair, the customized metal specimen block does not exhibit the same drawbacks as the original component and / or the cutout and can be customized (utilizing the porous area and / or the brazing material) to, for example, change: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and / or mass. One or more brazing materials can be used to couple the replacement specimen block to the component in order to also improve performance characteristics related to the joint, such as joint adhesive bond strength and reliability, and to reduce the post-brazing processing / mixing required. Additionally, the brazing reservoir also provides liquefied brazing material to hard-to-reach areas and is capable of providing motive force to various brazing areas (e.g., porous areas, cracks, and interfaces between the specimen and the component body). The pressurized and liquefied brazing material from the brazing reservoir (pressurized by the heat in the first chamber) can penetrate various brazing areas that typically cannot receive liquefied brazing material entering by gravity and / or capillary action. When used in the body of a component, the brazing reservoir can provide self-repair, for example, for internal cracks, during use of the component or during heat treatment without additional processing.

[0041] Figure 1 FIG. 1 shows a schematic view of an exemplary industrial machine that may include components in accordance with the teachings of the present disclosure. In this example, the machine includes a turbine 100 in the form of a combustion or gas turbine (GT) system. Turbine 100 includes a compressor 102 and a combustor 104. Combustor 104 includes a combustion zone 106 and a fuel nozzle assembly 108. Turbine 100 also includes a turbine assembly 110 and a common compressor / turbine shaft or rotor 112. In one embodiment, turbine 100 is a 7HA.03 engine commercially available from GE Vernova. The present disclosure is not limited to any particular GT system and can be implemented in combination with other engines, including, for example, other HA, F, B, LM, GT, TM, and E-class engine models of GE Vernova and engine models of other companies. Additionally, the present disclosure is not limited to any particular turbine and can be applicable to, for example, steam turbines, jet engines, compressors, turbofans, etc. Further, the present disclosure is not limited to any particular turbine component and can be applicable to any industrial component that utilizes a specimen block during manufacturing or repair.

[0042] In operation, air flows through compressor 102 and compressed air is supplied to combustor 104. Specifically, the compressed air is supplied to fuel nozzle assembly 108, which is integral with combustor 104. Assembly 108 is in fluid communication with combustion zone 106. Fuel nozzle assembly 108 is also in fluid communication with a fuel source ( Figure 2 not shown in FIG. 1) and delivers fuel and air to combustion zone 106. Combustor 104 is ignited and the fuel is burned. Combustor 104 is in fluid communication with turbine assembly 110 so that the thermal energy of the gas flow is converted into mechanical rotational energy. Turbine assembly 110 includes a turbine 111 that is rotatably coupled to rotor 112 and drives the rotor. Compressor 102 is also rotatably coupled to rotor 112. In the exemplary embodiment, there are multiple combustors and fuel nozzle assemblies 108.

[0043] Figure 2 FIG. 2 shows a cross-sectional view of an exemplary turbine assembly 110 of turbine 100 ( Figure 1 ) which may be associated with Figure 1for use with a gas turbine system. The turbine 111 of the turbine assembly 110 includes a row of nozzles or vanes 120 coupled to a stationary housing 122 of the turbine 100 and an axially adjacent row 124 of rotating blades 132. The stationary vanes or nozzles 126 can be retained in the turbine assembly 110 by a radially outer platform 128 and a radially inner platform 130. The row 124 of blades in the turbine assembly 110 includes rotating blades 132 that are coupled to the rotor 112 and rotate therewith. The rotating blades 132 can include a radially inner platform 148 (at the root of the blade) coupled to the rotor 112 and an optional radially outer tip shroud 136 (at the tip of the blade). As used herein, the term "component" can collectively refer to the stationary nozzles 126, the rotating blades 132, or any other structure in which a metal specimen block including a porous region according to the present disclosure can be employed.

[0044] Figure 3 and Figure 4 illustrates exemplary components of a turbine in which the teachings of the present disclosure can be employed, such as hot gas path components. Figure 3 shows a perspective view of a turbine rotor blade 132 of the type in which embodiments of the present disclosure can be employed. The turbine rotor blade 132 includes a root 140 through which the rotor blade 132 is attached to the rotor 112 ( Figure 2 ). The root 140 can include a dovetail 142 configured to be installed in a corresponding dovetail groove in the periphery of a rotor wheel 144 ( Figure 2 ) of the rotor 112 ( Figure 2 ). The root 140 can also include a shank 146 extending between the dovetail 142 and the platform 148, the platform being disposed at the junction of the airfoil 150 and the root 140 and defining a part of the inner boundary of the flow path through the turbine assembly 110. It should be understood that the airfoil 150 is the active part of the rotor blade 132 that intercepts the flow of the working fluid 151 ( Figure 2 ) (i.e., hot combustion gases) and causes the rotor disk to rotate. It can be seen that the airfoil 150 of the rotor blade 132 includes a concave pressure side (PS) outer wall 152 and a circumferentially or laterally opposite convex suction side (SS) outer wall 154, which axially extend 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 outer tip 160, which may or may not include a tip shroud 136 ( Figure 2 ).

[0045] Figure 4 shows a perspective view of a stationary nozzle 126 of the type in which embodiments of the present disclosure can be employed. The stationary nozzle 126 includes an outer platform 170 through which the stationary nozzle 126 is attached to the stationary housing 122 of the turbineFigure 2 )。The outer platform 170 may include any presently known or later developed mounting configuration for mounting in corresponding mountings in the housing. The stationary nozzle 126 may also include an inner platform 174 for positioning between adjacent turbine rotor blades 132( Figure 3 ) and the platform 148( Figure 3 ). The platforms 170, 174 define respective portions of the outer and inner boundaries of the flow path through the turbine assembly 110. It will be appreciated that the airfoil 176 is a movable part of the stationary nozzle 126 that intercepts the flow of the working fluid and directs that flow towards the turbine rotor blades 132( Figure 3 ). As can be seen, the airfoil 176 of the stationary nozzle 126 includes a concave pressure side (PS) outer wall 178 and a circumferentially or laterally opposed convex suction side (SS) outer wall 180 that axially extend 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.

[0046] It should be understood that the blades 132 or nozzles 126 may include internal cooling structures that include a coolant source, such as channels, conduits, and other structures that deliver coolant to their surfaces for film cooling. The coolant may include, for example, air from the compressor 102.

[0047] The embodiments of the present disclosure described herein may include aspects applicable to the stationary nozzle 126, the turbine rotor blades 132, and / or any other industrial components employing specimen blocks. Figure 3 and Figure 4 An exemplary additive manufacturing (AM) metal specimen block 200 (hereinafter simply referred to as "metal specimen block 200" or "AM metal specimen block 200") in the component 202 is also shown. More specifically, the metal specimen block 200 may be located in a specimen block opening 204 in a body 206 of the component 202. The "specimen block opening 204 in the body 206" may be any sized void in the body 206 up to and including a removed section (e.g., tip shroud) of the body 206. For example, the metal specimen block 200 may be located in the openings 204 in the trailing edges 158, 184 of the blades 132 or nozzles 126, respectively. Alternatively, the metal specimen block 200 may be located in the openings 204 in the leading edges 156, 182 of the blades 132 or nozzles 126, respectively. The metal specimen block 200 may also be located in any tip (not shown) of the blade 132 or in the platforms 170 (shown in Figure 4 ), 174 of the nozzle 126. However, it should be emphasized that the metal specimen block 200 may be used in any specimen block opening 204 in the body 206 of the component 202. The body 206 may be any part or all of the component 202.

[0048] The additive manufacturing (AM) metal specimen block 200 and / or the additive manufacturing (AM) component 202 that includes a brazing reservoir and / or one or more porous regions can be manufactured using any currently known or later developed technique capable of forming porous regions. Figure 5 FIG. shows a schematic / block diagram of an exemplary computerized metal powder additive manufacturing system 210 (hereinafter referred to as "AM system 210") for generating the metal specimen block 200, the component 202, multiple metal specimen blocks 200A, 200B (shown), or multiple components 202, with only a single layer shown. The teachings of the present disclosure will be described with respect to constructing the metal specimen block 200 or the component 202 using multiple 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 constructing multiple specimen blocks 200A, 200B and / or components 202 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., other than metal powder applications). The specimen blocks 200A, 200B are illustrated as rectangular elements; however, it should be understood that the additive manufacturing method can be readily adjusted to manufacture specimen blocks or components of any shape, a variety of different specimen blocks or components, and a large number of specimen blocks or components on the build platform 220.

[0049] 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 set of computer-executable instructions or code 234 to use a plurality of melt beam sources 212, 214, 216, 218 to generate a specimen block 200 or a component 202. In the example shown, the four melt beam sources can include four lasers. However, the teachings of the present disclosure apply to any melt beam source, such as an electron beam, a laser, etc. The control system 230 is shown as being implemented as computer program code on a computer 236. To that extent, the computer 236 is shown as including a memory 238 and / or a storage system 240, a processor unit (PU) 244, an input / output (I / O) interface 246, and a bus 248. In addition, the computer 236 is shown as communicating with an external I / O device / resource 250. 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 the computer program code 234, the processor unit (PU) 244 can read from and / or write to the memory 238, the storage system 240, the I / O device 250, and / or the AM printer 232. The bus 248 provides a communication link between each of the components in the computer 236, and the I / O device 250 can include any device that enables a user to interact with the computer 236 (e.g., a keyboard, a pointing device, a display, etc.). The computer 236 represents only various possible combinations of hardware and software. For example, the processor unit (PU) 244 can include a single processing unit or be distributed across one or more processing units at one or more locations (e.g., on a client and a server). Similarly, the memory 238 and / or the storage system 240 can reside at one or more physical locations. The memory 238 and / or the storage system 240 can include any combination of various types of non-transitory computer-readable storage media, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), etc. The computer 236 can include any type of computing device, such as an industrial controller, a network server, a desktop computer, a laptop computer, a handheld device, etc.

[0050] As noted, the AM system 210 and specifically the control system 230 execute code 234 to produce the metal specimen block 200 or component 202. Among other things, the code 234 can include a set of computer-executable instructions 234S (also referred to herein as "code 234S") for operating the AM printer 232, and a set of computer-executable instructions 234O (also referred to herein as "code 234O") that define the metal specimen block 200 or component 202 to be physically produced by the AM printer 232. As described herein, the additive manufacturing method begins with storing the code 234 in a non-transitory computer-readable storage medium (such as the memory 238, the storage system 240, etc.). The set of computer-executable instructions 234S for operating the AM printer 232 can include any currently known or later-developed software code capable of operating the AM printer 232.

[0051] The set of computer-executable instructions 234O that define the metal specimen block 200 or component 202 can include a precisely defined 3D model of the specimen block and can be generated by any of a variety of well-known computer-aided design (CAD) software systems (such as DesignCAD 3D Max, etc.). In this regard, the code 234O can include any currently known or later-developed file format. Additionally, the code 234O representing the metal specimen block 200 or component 202 can be transformed between different formats. For example, the code 234O can include a Standard Tessellation Language (STL) file created for a stereolithography CAD program for 3D systems or an Additive Manufacturing File (AMF) as an American Society of Mechanical Engineers (ASME) standard, which is an Extensible Markup Language (XML)-based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be manufactured on any AM printer. The code 234O representing the metal specimen block 200 or component 202 can also be converted into a set of data signals as needed and transmitted, received, and converted back into code, stored, etc. The code 234O can be configured according to the embodiments of the present disclosure to allow the formation of boundaries and internal sections in the overlapping field regions, as will be described. In any case, the code 234O can be an input to the AM system 210 and can come from a parts designer, an intellectual property (IP) provider, a design company, an operator or owner of the AM system 210, or other sources. In any case, the control system 230 executes the code 234S and 234O to divide the metal specimen block 200 or component 202 into a series of thin slices that are assembled using the AM printer 232 in successive layers of material.

[0052] The AM printer 232 may include a processing chamber 260 that is sealed to provide a controlled atmosphere for printing the metal specimen block 200 or the component 202. The build platform 220 on which the metal specimen block 200 or the component 202 is built is positioned within the processing chamber 260. A plurality of melt beam sources 212, 214, 216, 218 are configured to melt a layer of metal powder on the build platform 220 to generate the specimen block 200 or the component 202. Although four melt beam sources 212, 214, 216, 218 are shown, it should be emphasized that the teachings of the present disclosure apply to systems employing any number of sources (e.g., 1, 2, 3, or 5 or more). As is understood in the art, each melt beam source 212, 214, 216, 218 may respectively have a field including non-overlapping field regions in which the melt beam source can exclusively melt the metal powder, and the melt beam source may include at least one overlapping field region in which two or more sources can melt the metal powder. In this regard, each melt beam source 212, 214, 216, 218 may respectively generate a melt beam that melts the particles of each slice, as defined by the code 234O. For example, in Figure 5 , the melt beam source 212 is shown using the melt beam 262 to form a layer of the metal specimen block 200 or the component 202 in one region, while the melt beam source 216 is shown using the melt beam 262' to form a layer of the metal specimen block 200 or the component 202 in another region. Each melt beam source 212, 214, 216, 218 is calibrated in any presently known or later developed manner. That is, each melt beam source 212, 214, 216, 218 already has an expected position of its laser or electron beam relative to the build platform 220 that is related to the actual position of the laser or electron beam, so as to provide individual position correction (not shown) to ensure its individual accuracy. In one embodiment, each of the plurality of melt beam sources 212, 214, 216, 218 may form a melt beam having the same cross-sectional dimensions (e.g., shape and size in operation), power, and scan speed, such as 262, 262'.

[0053] Continuing to refer to Figure 5, the coater (or recoater blade) 270 can form a thin layer of the raw material 272, which spreads out as a blank canvas on which each successive slice of the final specimen block will be formed. Various parts of the AM printer 232 can be moved 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 process can use different raw materials in the form of fine-grained metal powders, and the stocks of these raw materials can be kept in the chamber 260 accessible by the coater 270. In this case, the specimen block 200 or the component 202 can be made of a metal, which can include pure metals or alloys. In one example, the metal can include almost 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., X); or nickel-chromium-cobalt-molybdenum alloy (NiCrCoMo) (e.g., Haynes 282 available from Haynes International, Inc.). Other possibilities include, for example, René 108, CM 247LC, Mar M 247, and any precipitation-hardened (PH) nickel alloys.

[0054] 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 rate of the gas mixture 274 from the inert gas source 276 within the processing chamber 260. In this case, the control system 230 can control the pump 280 and / or the flow valve system 282 for the inert gas to control the content of the gas mixture 274. The flow valve system 282 can include one or more computer-controlled valves, flow sensors, temperature sensors, pressure sensors, etc. that can precisely control the flow rate of a specific gas. The pump 280 can be provided with or without a valve system 282. In the case where the pump 280 is omitted, the inert gas can simply enter the pipeline or manifold before being introduced into the processing chamber 260. The inert gas source 276 can take the form of any conventional source for the materials contained therein, such as a tank, reservoir, or other source. Any sensors (not shown) required to measure the gas mixture 274 can be provided. The gas mixture 274 can be filtered in a conventional manner using the filter 286.

[0055] In operation, a build platform 220 having metal powder thereon is disposed within a processing chamber 260, and a control system 230 controls the flow of a gas mixture 274 from an inert gas source 276 within the processing chamber 260. According to an embodiment of the present disclosure, the control system 230 also controls an AM printer 232, particularly a coater 270 and melting beam sources 212, 214, 216, 218, to sequentially melt a layer of metal powder on the build platform 220 to generate a metal specimen block 200 or a component 202.

[0056] Although a specific 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. Further, although the teachings of the present disclosure relate to additive manufacturing of a metal specimen block 200 or a component 202, it should be understood that in cases where the component 202 does not include a brazing reservoir or a porous region, the component 202 may be manufactured by any presently known or later developed means, such as casting or other methods. The component 202 may include any of the materials listed herein for the metal specimen block 200.

[0057] As noted, in certain embodiments of the present disclosure, the metal specimen block 200 includes an additive manufacturing (AM) metal member 290 that includes a brazing reservoir 292 located interiorly of the AM metal member 290. In other embodiments of the present invention, the component 202 includes a body 206 that includes a brazing reservoir 292. As will be further described, the brazing reservoir 292 may supply liquefied brazing material to a brazing region 294 that, in one instance, may include a porous region 300 located in the body 206 of the metal specimen block 200 and / or the component 202.

[0058] As used herein, "porosity" is the ratio of the volume of open space to the total volume of the structure (e.g., a porous region, a metal specimen block, etc.). In this regard, porosity is typically expressed as a percentage of the volume of open space to the total volume or overall volume of the structure. Open space is the empty area within a solid material and may be referred to herein as "pores" 302 and may include interconnected channels within the material of the stated structure. Thus, the "porous region" within the metal specimen block 200 is less than 100% solid and includes open space in the form of pores 302 and / or interconnected channels. The porous metal specimen block 200 may include solid regions but also includes one or more porous regions (as part of the brazing region 294) that are less than 100% solid. As used herein, the three-dimensional boundaries for a porous region or sub-region identifying its "total volume" may be identified by a change in porosity greater than 2% relative to an adjacent region or sub-region within the metal specimen block 200 and / or the presence of an edge of the metal specimen block 200. The "volume of open space" collectively refers to the empty three-dimensional space (i.e., voids, gaps, empty space) within a region or sub-region and / or unfilled material. As used herein, "different porosities" or "differences in porosity" generally refer to any kind of property, such as: the percentage of the volume of open space to the total volume, the number of pores 302 in a given volume, the volume (i.e., size) of the pores 302, the shape of the pores 302, and variations in the connecting openings between the pores 302 (referred to herein as "pore connection channels") which may not be considered actual discrete pores. The pore size may be in the range of, for example, 0.025 cubic millimeters to 0.381 cubic millimeters (0.0001 cubic inches to 0.015 cubic inches). In cases where there are differences such as in pore shape or pore connection channels, it will be recognized that the differences in porosity may not be based solely on the percentage of the volume of open space to the total volume. However, in cases where differences in porosity are compared in terms of degree (e.g., higher or lower), the differences referred to are solely differences in volume properties, i.e., the percentage of the volume of open space to the total volume. In the figures, different porous regions or sub-regions are typically shown as continuous or in contact with each other, however, it should be emphasized that these porous regions or sub-regions may be isolated from each other in any way, such as having solid regions between these porous regions or sub-regions. That is, a single metal specimen block may include one or more isolated, non-contact porous regions.

[0059] A porous metal specimen block 200 including different porous regions having different porosities (which may or may not include one or more sub-porous regions having different porosities) can be formed using the AM system 210 as described herein or any other metal additive manufacturing system or method capable of forming porous metal. In terms of the operation of the AM system 210, the melting beam sources 212, 214, 216, 218 can be programmed to intermittently not sinter the metal to leave metal powder instead of solid material. This process can include overlapping the laser field regions in different amounts and / or designing the holes 302 into the build file, i.e., the code 234O. Less overlap per laser scan forms a larger porosity, and more laser overlap between successive scans forms a smaller porosity. The laser spot size, scan speed, focal length, and power can also be controlled to adjust the porosity. When the un-melted metal powder is removed from the metal specimen block 200, it leaves holes 302 with interconnected channels therebetween and forms one or more porous regions in the metal specimen block 200. In any case, the layer-by-layer fabrication of the metal specimen block 200 can be controlled to form the desired porosity for any number, shape, and / or size of porous regions within any desired layer of the metal specimen block 200.

[0060] Figures 6A to 6D A top schematic view of a sample metal specimen block 200 having different porosities is shown. The holes 302 are shown as darker open spaces in the drawing. Figure 6A A sample metal specimen block 200 having a first porosity with an open space volume of approximately 40% of the total sample volume (having generally a low amount of open space and more or larger holes 302) is shown, Figure 6B A sample metal specimen block 200 having a first porosity with an open space volume of approximately 30% of the total sample volume is shown, Figure 6C A sample metal specimen block 200 having a first porosity with an open space volume of approximately 20% of the total sample volume is shown, Figure 6DA sample metal specimen block 200 (having a generally low amount of open space) with a first porosity of approximately 10% of the total volume of the sample where the open space volume is shown. Each porous region can have a porosity of 2% to 50% of the total volume of the porous region (i.e., 2% to 50% open space and the other 50% to 98% solid). In other embodiments, each porosity can be 10% to 40% of the total volume of the porous region 300 (i.e., 10% to 40% open space and the other 60% to 90% solid). In other embodiments, a porous region can be provided in the metal specimen block 200 having a porosity in the range of less than 10%, in the range of less than 15%, in the range of less than 20%, in the range of less than 25%, in the range of less than 30%, in the range of less than 35%, in the range of less than 40%, in the range of less than 45%, in the range of 2% to 45%, in the range of 2% to 40%, in the range of 2% to 35%, in the range of 2% to 30%, in the range of 2% to 25%, in the range of 2% to 20%, in the range of 5% to 45%, in the range of 5% to 40%, in the range of 5% to 35%, in the range of 5% to 30%, in the range of 5% to 25%, in the range of 5% to 20%, in the range of 10% to 45%, in the range of 10% to 40%, in the range of 10% to 35%, in the range of 10% to 30%, in the range of 10% to 25%, in the range of 10% to 20%, in the range of 15% to 45%, in the range of 15% to 40%, in the range of 15% to 35%, in the range of 15% to 30%, in the range of 15% to 25%, in the range of 15% to 20%, in the range of 10% to 50%, in the range of 20% to 50%, in the range of 25% to 50%, in the range of 30% to 50%, in the range of 35% to 50%, in the range of 40% to 50%. As will be described herein, other ranges of porosity are also possible.

[0061] Figures 7A to 7D A schematic cross-sectional view of an exemplary brazing reservoir 292 in a metal specimen block 200 or component 202 according to an embodiment of the present disclosure is shown. The metal specimen block 200 includes an AM metal member 290 having a brazing reservoir 292 therein. Here, the brazing reservoir 292 is located inside the AM metal member 290. The component 202 includes a body 206 having a brazing reservoir 292 therein. Here, the brazing reservoir 292 is located inside the body 206.

[0062] First with respect to the metal specimen block 200, as Figures 7A to 7DAs shown, the brazing reservoir 292 includes: a first cavity 320 located in the AM metal member 290; a second conduit 322 fluidly connecting the first cavity 320 to the outer surface 306 of the AM metal member 290; and a first conduit 324 fluidly connecting the first cavity 320 to the brazing area 294. As used herein, conduits 322, 324 are elongated channels or open spaces configured to direct unmelted metal powder brazing material or melted brazing material therethrough. Further, cavity 320 is not an elongated or less elongated open space configured to contain or store unmelted first brazing material 328 (but allows melted brazing material to flow out through conduits in fluid communication therewith). The cavity and conduits can be formed by programming the melt beam sources 212, 214, 216, 218 of the AM system 210 not to sinter metal in certain regions of the metal specimen block 200 or component 202, thereby leaving metal powder rather than solid material. Once the metal specimen block 200 or component 202 is complete, the unmelted metal powder can be removed, leaving the cavity and / or conduits. The brazing reservoir 292 further includes: a first brazing material 328 located in the first cavity 320; and a seal member 330 separating the second conduit 322 from the exterior of the AM metal member 290. After additive manufacturing of the metal specimen block 200, the first brazing material 328 is introduced (inserted) into the first cavity 320 through the second conduit 322. As will be further described herein, the first brazing material 328 can be introduced into the first cavity 320 in a controlled atmosphere, such as in a non-reactive gas (such as but not limited to argon and / or nitrogen). The first brazing material 328 can be in powder form or non-powder form, such as a paste made from powder and a binder (e.g., Braz-Binder Gel available from Vitta). The brazing material 328 (or any brazing material described herein, such as 360) can include any currently known or later developed brazing composition, such as but not limited to: GE (Alstom) B1P, Amdry TM D15, DF4B or BRB, some formulations of which are listed in the following table along with other brazing material formulations:

[0063]

[0064] Once the first brazing material 328 is located within the first cavity 320, a sealing member 330 is formed to seal the second conduit 322. The sealing member 330 can include any structure capable of closing the second conduit 322 at or near the outer surface 306 of the AM metal member 290, i.e., after the first brazing material 328 has been introduced into the first cavity 320 through the second conduit 322. For example, the sealing member 330 can include a plug or a weld in the second conduit 322 at or near the outer surface 306 of the AM metal member 290.

[0065] The brazing reservoir 292 can also include a blocking member 332 that blocks fluid communication through the first conduit 324 between the first cavity 320 and the brazing region 294. The blocking member 332 blocks fluid communication through the first conduit 324 between the first cavity 320 and the brazing region 294 until the blocking member 332 is exposed to a predetermined temperature that exceeds the melting temperature of the first brazing material 328. The blocking member 332 can include any material having a melting temperature lower than that of the AM metal member 290 and higher than or equal to that of the first brazing material 328. In certain embodiments, the blocking member 332 can include a eutectic mixture of at least one element of the metal material of the AM metal member 290 and the first brazing material 328. In such a case, the blocking member 332 can be formed by additive manufacturing using the AM metal member 290 (i.e., using the same material as the AM metal member 290), and then (once the first brazing material 328 is introduced into the first cavity 320) the absorption of elements in the first brazing material 328 changes the melting temperature of the blocking member compared to the remainder of the AM metal member 290.

[0066] In one example, the AM metal component 290 (specimen block 200) and the barrier component 332 can include superalloys (such as, In-738, In-738LC, MAR-M-247, Rene-108, GTD-111), or variants designed for additive manufacturing, or any other superalloys common to turbine components, and the first brazing material 328 can include any of the brazing materials listed herein. The barrier component 332 is a relatively thin layer of material compared to the remainder of the AM metal component 290, and thus absorbs a relatively large volume of elements (such as boron) in the first brazing material 328 compared to the remainder of the AM metal component 290 (e.g., around the first cavity 320 or conduits 322, 324), which reduces its melting temperature. That is, when the metallic material around the first cavity 320 or conduits 322, 324 absorbs elements in the first brazing material 328, they are too thick to allow these elements to change their physical properties. Instead, the barrier component 332 can become a eutectic, i.e., it is a mixture of substances that melts at a temperature below the melting points of its individual components. More specifically, the first brazing material 328 includes a "low melting point" brazing material commonly used to repair superalloy components, which contains an amount of elements (such as but not limited to boron and / or silicon) greater than that otherwise found in superalloys to reduce the melting temperature of the first brazing material 328. When the first brazing material 328 is held at an elevated temperature (e.g., near or above its melting temperature), the melting-inhibiting elements diffuse into the surrounding region. This elevated temperature can occur due to the insertion of the brazing material 328 into the first cavity 320, or a separate heat treatment can be performed to cause the diffusion. In any case, this diffusion reduces the local concentration of elements around the first brazing material 328 in the first cavity 320 and increases their concentration in the surrounding superalloy (including in the barrier component 332). The diffusion zone can be, for example, 50 microns to 254 microns (about 0.002 inches to 0.010 inches) into the superalloy (i.e., the barrier component 332), which significantly increases the temperature at which the barrier component 332 melts to melt the first brazing material 328 during subsequent thermal cycles.

[0067] As a result of the foregoing construction, the barrier member 332 can serve as a one-time (possibly eutectic) valve that can open at a predetermined temperature above the melting temperature of the first brazing material 328 (i.e., can melt, dissolve, or rupture to allow the liquefied brazing material 328 to flow therethrough). More specifically, the brazing reservoir 292 is thermally triggered (i.e., activated) by the metal specimen block 200 and / or the component body 206 reaching a predetermined temperature above the melting temperature of the first brazing material 328. This predetermined temperature may not need to be higher than the melting temperature of the barrier member 332 in order to open it. For example, the liquefied first brazing material 328 can combine with the increased pressure generated by the predetermined temperature in the first chamber 320 to open the barrier member 332, e.g., dissolve or forcefully rupture the barrier member 332. Alternatively, the liquefied first brazing material 328 can simply dissolve the barrier member 332 in such a way that the liquefied first brazing material 328 can flow into the first conduit 324. In another alternative, the predetermined temperature can be higher than the melting temperature of the barrier member 332 in order to melt it to open it. In any case, the barrier member 332 can be opened by any one of melting, dissolving, and / or rupturing.

[0068] The barrier member 332 can have any shape and / or profile to block the first conduit 324. The thickness of the barrier member 332 can depend on, for example, the materials of the first brazing material 328 and the metal specimen block 200. In one non-limiting example, the barrier member 332 can have a thickness of less than 1270 microns (about 0.050 inches), and in another example, can have a thickness between 50 microns and 254 microns (about 0.002 inches to 0.010 inches). The barrier member 332 can have a constant or varying thickness and / or surface finish.

[0069] Continuing to refer Figures 7A to 7D to component 202, the brazing reservoir 292 in component 202 is substantially similar to the brazing reservoir described with respect to the metal specimen block 200. Figure 3 、 Figure 4 and Figure 11The brazing reservoir 292 in the component 202 is shown. In this case, the brazing reservoir includes: a first chamber 320 that is located in the body 206 (not the AM metal member 290); a second conduit 322 that fluidly couples the first chamber 320 to the outer surface 334 of the body 206; and a first conduit 324 that fluidly couples the first chamber 320 to the brazing area 294. As noted, the chamber and conduits can be formed by programming the melt beam sources 212, 214, 216, 218 of the AM system 210 not to sinter the metal in certain regions of the component 202, thus leaving metal powder rather than solid material. Once the component 202 is complete, the unmelted metal powder can be removed, leaving the chamber and / or conduits. The brazing reservoir 292 further includes: a first brazing material 328 that is located in the first chamber 320; and a seal member 330 that separates the second conduit 320 from the exterior of the body 206. After the component 202 has been additively manufactured, the first brazing material 328 is introduced (inserted) into the first chamber 320 through the second conduit 322. As noted, the first brazing material 328 can be inserted into the first chamber 320 in a controlled atmosphere, such as in a non-reactive gas (such as but not limited to argon and / or nitrogen). As noted, the first brazing material 328 can be in powder form or non-powder form, such as a paste made from powder and a binder (e.g., Braz-Binder Gel available from Vitta). Once the first brazing material 328 is located in the first chamber 320, the seal member 330 is formed to seal the second conduit 322. The seal member 330 can include any structure capable of closing the second conduit 322 at or near the outer surface 334 of the body 206, i.e., after the first brazing material 328 has been introduced into the first chamber 320 through the second conduit 322. For example, the seal member 330 can include a plug or weld in the second conduit 322 at or near the outer surface 334 of the body 206.

[0070] The brazing reservoir 292 in the component 202 may further include a barrier member 332 that blocks fluid communication through the first conduit 324 between the first chamber 320 and the brazing region 294 before the metal specimen block 200 or the component body 206 (wherever it is located) is exposed to a predetermined temperature that exceeds the melting temperature of the first brazing material 328. Here, the barrier member 332 may include any material having a melting temperature that is lower than the material of the body 206 and higher than or equal to the melting temperature of the first brazing material 328. In some embodiments, the barrier member 332 becomes a eutectic mixture of at least one element of the metal material of the body 206 and the first brazing material 328. In such cases, the barrier member 332 may be formed by additive manufacturing using the body 206 (i.e., using the same material as the body 206) and then absorbing elements from the first brazing material 328 (once the first brazing material 328 is introduced into the first chamber 320 (and optionally a heat treatment is performed)), and the melting temperature of the barrier member 332 changes compared to the rest of the body 206. As noted, the barrier member 332 is a relatively thin layer of material compared to the rest of the body 206, and thus absorbs a relatively large volume of certain elements (e.g., boron) from the first brazing material 328 compared to the rest of the body 206 (e.g., around the first chamber 320 or conduits 322, 324), which reduces its melting temperature. That is, when the metal material around the first chamber 320 or conduits 322, 324 absorbs elements (e.g., boron) from the first brazing material 328, they are too thick for these elements to change their physical properties. Instead, the barrier member 332 becomes a eutectic. In this way, the barrier member 332 can be used as a disposable eutectic valve that can open (i.e., melt, dissolve, or break) at a predetermined temperature that exceeds the melting temperature of the first brazing material 328 to allow the liquefied brazing material 328 to flow therethrough).

[0071] Refer to Figure 7D, in an alternative embodiment applicable to a metal specimen block 200 or component 202 having a brazing reservoir 292, a second cavity 340 may be defined in the AM metal member 290 or body 206. The second cavity 340 may be an enlarged region of a first conduit 324 between the first cavity 320 and the brazing region 294. The second cavity 340 has a second brazing material 342 therein that is different from the first brazing material 328. In certain embodiments, the second brazing material 342 may have a melting temperature higher than that of the first brazing material 328, but low enough such that the liquefied first brazing material 328 can direct the second brazing material 342 in solid or molten form to the brazing region 294. The second brazing material 342 may include unmelted metal powder for forming the metal specimen block 200 or component 202, i.e., superalloy metal powder. Here, after additive manufacturing, the unmelted metal powder remains in the metal specimen block 200 or component 202 rather than being removed.

[0072] The brazing region 294 may take various forms, depending on the intended application of the metal specimen block 200, component 202, and / or brazing reservoir 292. Notably, the brazing region 294 may be any region or location where additional brazing material may be desired to, for example, ensure that all regions to be brazed are filled with brazing material, such as a joint 384 ( Figures 10A to 10E ) between parts or a porous region 300 for directing the liquefied brazing material in a desired manner, and / or to ensure filling / repair of potentially damaged regions (e.g., cracking or other high-stress damage). For example, the brazing region 294 may include at least one of the following: as Figure 7B and Figure 7D shown, a porous region 300 within the AM metal member 290 or body 206; or as Figure 7A shown, a contact interface 346 between the AM metal member 290 or body 206 and another member; or as Figure 7C shown, a damaged region 348, such as a crack, in a portion of the body 206 of the AM metal member 290 or component 202; or as Figure 7A shown, a portion of the body 206 of the component 202 (e.g., specimen block opening 204) in which the AM metal member 290 (metal specimen block 200) is located. As Figure 7A shown, the brazing region 294 may also be the outer surface 306 of the AM metal member 290 of the metal specimen block 200 or the outer surface 334 of the body 206 of the component 202, respectively. As will be further described, the porous region 300 may have a variable porosity, where two or more porous sub-regions 314 ( Figure 7B ) have different porosities, for example, to direct the brazing materials 328, 342, and other brazing materials in a desired manner.

[0073] It should be noted that the damaged area 348 can be an area where damage is more likely but not necessarily to occur, such as a high stress area in the metal specimen block 200, in the body 206 of the component 202, or in the area between the two. For example, the damaged area 348 can be a location (e.g., a corner) in the metal specimen block 200, in the body 206 of the component 202, or in the area between the two, which is exposed to high stress and can be repaired by filling the brazing material 328 and / or 342. The contact interface 346 can be located between any parts that require the brazed joint 384 ( Figures 10A to 10E ). For example, as Figure 10B shown, the contact interface 346 can be located between the AM metal member 290 of the metal specimen block 200 and the specimen block opening 204 in the body 206 of the component 202 where the AM metal member 290 is located. Here, the brazing reservoir 292 can provide additional brazing to the brazing area 294 in the form of the joint between the metal specimen block 200 and the specimen block opening 204 of the body 206. For example, in the case where the brazing that is usually applied to the outer surfaces 306, 334 of the metal specimen block 200 and the body 206 does not penetrate deep enough into the contact interface 346 to ensure a sufficient brazed joint. The brazing reservoir 292 can be arranged to deliver the brazing materials 328, 342 to any form of brazing area 294 when a predetermined temperature is applied. The heat applied to the first chamber 320 raises the pressure therein, causing the liquefied brazing material 328 to be forced into the first conduit 324. Although each brazing reservoir 292 is illustrated as having a single first conduit 324 to deliver the liquefied brazing material 328 to a single brazing area 294, as Figure 7C and Figure 8D shown, it should be understood that in any of the illustrated embodiments, more than one first conduit 324 can be provided, and thus more than one brazing area 294 is provided with the liquefied brazing materials 328, 342. In Figure 7C and Figure 8D , the second brazing area 294X is illustrated as a porous area 300, but it can be any form of brazing area described herein.

[0074] Figures 8A to 8EA perspective view of an exemplary AM metal specimen block 200 is shown that includes an additive manufacturing (AM) component 290 having one or more porous regions 300 (with pores 302). The porous regions 300 are infiltrated with brazing material. The liquefied brazing material 328 (and possibly also brazing material 342) for the porous regions 292 can be supplied by a brazing reservoir 292 (such that these porous regions 300 become the "brazing regions" 294 of these brazing reservoirs 300). Alternatively, the porous regions 300 can be supplied with another (third) brazing material 360 by a different means than from the brazing reservoir 292, such as by applying the brazing material 360 to the exterior of the metal specimen block 200 and heating to cause flow by gravity and / or capillary action. In another embodiment, the porous regions 300 can be supplied with a third brazing material 360 and a first brazing material 328 (and possibly also a second brazing material 342) from the brazing reservoir 292.

[0075] As Figure 8A shown, the metal specimen block 200 can include a first porous region 300 having a first porosity. In Figure 8A this case, the metal specimen block 200 includes a single porous region 300 having a single first porosity. In Figure 8A this case, the entire metal specimen block 200 includes the first porosity. Thus, each layer of the metal specimen block 200 has the same porosity. In Figure 8B and Figure 8E this case, the metal specimen block 200 includes two porous regions 300A to 300B each having a different porosity. In Figure 8B this case, the two different porous regions 300A, 300B are a layered inner region and outer region, where one region is closer to the interior of the metal specimen than the other, and in Figure 8E this case, the two different porous regions 300A, 300B are different sides of the metal specimen block 200. The zones defining the regions 300A to 300B within the layers of the metal specimen block 200 can be formed to include pores 302. In Figure 8C this case, the metal specimen block 200 includes one or more porous regions 300C and solid regions 304, each porous region possibly having the same or different porosity. Here, the zones within the layers of the metal specimen block 200 defining the regions 300A to 300B can be formed to include pores 302, and the zones within the layers of the metal specimen block 200 defining the solid regions 304 are formed without pores 302. In Figure 8DIn this case, the metal specimen block 200 includes a variable porosity region 312 that is located between a first porous region 300A and a second porous region 300B (and may include portions of the first and second porous regions). Here, regions 300A to 300B or regions of the variable porous region 312 defined within the layer of the metal specimen block 200 can be formed to include, for example, different sizes or numbers of pores 302 to produce different porosities. The variable porosity region 312 can have any porosity that varies (e.g., increases, decreases, and / or both increases and decreases). The change in porosity can be gradual or stepped or incremental in some other way. Although the variable porous region 312 is shown in Figure 8D as being located between an outer porous region 300A and an inner porous region 300B, the variable porous region can also be applied to Figure 8E versions. Each porous region 300 can have a porosity of 2% to 50% open space volume of the total volume of the porous region 300 (i.e., 2% to 50% open space and the other 50% to 98% solid). In other embodiments, each porosity can be 10% to 40% open space volume of the total volume of the porous region 300 (i.e., 10% to 40% open space and the other 60% to 90% solid). Other ranges of porosity are possible. For example, the porous region 300 can have any porosity described herein.

[0076] As Figure 3 and Figure 4 shown, Figures 8A to 8E the metal specimen block 200 in

[0077] is shown as having a shape that is configured to be positioned in a specimen block opening 204 in the trailing edge 158 or 184 of a blade 132 or a nozzle 126, respectively, or in a specimen block opening 204 in the leading edge 156 or 182 of a blade 132 or a nozzle 126, respectively. The metal specimen block 200 can also be located in any tip (not shown) of a blade 132 or in the platform 170 (shown), 174 of a nozzle 126. However, it should be emphasized that the metal specimen block 200 can be used in any opening 204 in any part of the body 206 of any component 202. As noted, the "specimen block opening 204 in the body 206" can be any size void in the body 206 up to and including the removed section (e.g., tip shroud) of the body 206. Figures 8A to 8E shown, a brazing reservoir 292 can be located at any position within the metal specimen block 200 to deliver brazing materials 328, 342 when needed. In the case where the brazing reservoir 292 is defined within the porous metal, as Figure 8AAs shown, the cavities 320, 340 and / or conduits 322, 324 may be formed by a dense layer 364 (e.g., a braze barrier permeable layer) within the porous region 300 that surrounds the respective cavities 320, 340 and / or conduits 322, 324. Otherwise, a dense region (e.g., a solid region) may be defined within the porous metal to allow the cavities and conduits of the braze reservoir 292 to be defined therein.

[0078] Figure 8E An example of another embodiment in which the braze reservoir 292 can be removed from the AM metal component 290 is shown. In this case, the braze reservoir 292 can be formed in a section 370 of the AM metal component 290 of the metal coupon 200, which section can be removed later once the braze reservoir 292 has been used. That is, the section 370 is provided for the primary purpose of providing the braze reservoir 292, but it is not otherwise necessary to the component 202 or the metal coupon 200. Once the braze reservoir 292 is used, the section 370 of the AM metal component 290 in which the braze reservoir is located can be removed, for example, by grinding, electro-spark machining, etc. The remaining section 372 of the AM metal component 290 may not include any portion of the braze reservoir 292. For example, a similar approach may be used with the component 202 by forming the braze reservoir 292 in a section of the component 202 that is not needed for the finished component 202 and removing the section after the braze reservoir 292 is used.

[0079] As will be further described herein, and as Figure 3 , Figure 4 , Figures 9C to 9G , Figures 10A to 10E As shown, the brazing material 360 (outside the brazing reservoir 292) penetrates into the porous region 300 of the metal coupon 200 to couple the metal coupon 200 to the coupon opening 204 of the body 206 of the component 202. The different porosities and / or variable sub-regions differ from each other in at least one of the following characteristics: percentage of open space volume to total volume, pore shape, pore size, number of pores, and pore connectivity. Each porous region 300 or porous sub-region can have a porosity as previously described herein. The different porosities allow for controlled absorption of the brazing material 360, i.e., by capillary action, into the metal coupon 200. For illustration, with respect to Figure 8D The porous region 300 includes an outer porous region 300A adjacent to the outer surface 306 of the AM metal component 290, the outer porous region having a higher porosity than the inner porous region 300B. Therefore, the outer porous region 300A is configured to receive more brazing material 360 therein than the inner porous region 300B.

[0080] refer toFigure 3 , Figure 4 , Figures 8A to 8E , Figures 9A to 9G and Figures 10A to 10E , embodiments of a method according to the present disclosure will now be described. The method may include repairing component 202. Figures 9A to 9G A perspective view of a method according to an embodiment of the present disclosure is shown.

[0081] Figure 9A Forming a specimen block opening 204 in the body 206 of component 202 is shown. The specimen block opening 204 ultimately receives a metal specimen block 200. The specimen block opening 204 can have any desired shape. In some applications, the specimen block opening 204 is formed by removing a damaged portion of the body 206 of component 202, but the specimen block opening 204 can also be in the original form of component 202, e.g., at a challenging location where it is manufactured together with the rest of component 202. In the non-limiting example shown, the specimen block opening 204 is located in the trailing edge 184 of nozzle 126. Figure 9A A model for forming the specimen block opening 204 is also shown. Model formation may include using any currently known or later developed three-dimensional scanner (not shown, see arrow) to scan and form a digital representation of the specimen block opening 204 relative to the body 206 of component 202. Since methods for scanning and modeling parts are well known in the art, further details are omitted so that the reader can focus on the salient aspects of the present disclosure.

[0082] Figure 5 , Figures 7A to 7D and Figures 8A to 8E Additive manufacturing of a metal specimen block 200 for insertion into the specimen block opening 204 in the body 206 of component 202 is shown. Additive manufacturing includes forming an AM metal member 290 having a brazing reservoir 292 therein, as described herein. Generally speaking, the brazing reservoir 292 includes: a first chamber 320 located in the AM metal member 290; a second conduit 322 that fluidly couples the first chamber 320 to the outer surface 306 of the AM metal member 290; and a first conduit 324 that fluidly couples the first chamber 320 to a brazing region 294. The brazing reservoir 292 may further include a blocking member 332 that blocks fluid communication through the first conduit 324 between the first chamber 320 and the brazing region 294. The blocking member 332 blocks fluid communication through the first conduit 324 between the first chamber 320 and the brazing region 294 until the blocking member 332 is exposed to a predetermined temperature that exceeds the melting temperature of the first brazing material 328.

[0083] Additive manufacturing may include any of the AM processes described herein to fabricate the brazing reservoir 292 and, for example, the porous metal specimen block 200 (or component 202) having porous or dense metal. Additive manufacturing may include fabricating the metal specimen block 200 to generally match the shape of the specimen block opening 204, or to have a near-net shape of the specimen block opening 204 based on a model of the specimen block opening 204. As used herein, "near-net shape" indicates that the metal specimen block 200 has a certain external shape after fabrication that, when positioned in the specimen block opening 204, is very close to the surface required to couple the metal specimen block 200 in the specimen block opening 204 (e.g., using a selected brazing material and minimal required finishing methods such as machining or grinding) to the body 206. However, compared to a solid specimen block having a narrow gap for the brazing material, the use of the porous region 300 in the metal specimen block 200 accommodates greater variations in the joint gap size because, despite the larger gap, the porous region still provides improved brazing material grip and retention. Although the metal specimen block 200 is shown in Figures 9C to 9G as additively manufactured to have a shape from an embodiment such as Figures 8A to 8E , it may take any form described herein.

[0084] According to an embodiment of the present disclosure, the porosity of the porous region 300 or a sub-region thereof in the metal specimen block 200 is controlled (i.e., customized) to control the flow of the brazing material 360 therein during a subsequent brazing process in the specimen block opening 204 ( Figures 3 to 4 , Figures 10A to 10E ) of the body 206 ( Figures 3 to 4 , Figures 9E to 9G ) of the component 202 ( Figures 3 to 4 , Figures 9E to 9G ). Each porous region 300 or sub-region may be customized according to any of the aforementioned properties that affect porosity. The shape and / or location of the porous region 300 or a sub-region thereof may be arranged to direct the brazing material as needed. For example, in Figures 8A to 8B , the entire metal specimen block 200 includes a uniform porous region 300, and thus the brazing material 360 will be uniformly distributed therein. In contrast, in, for example, Figure 8D , the metal specimen block 200 includes an outermost porous region 300A near the edge 308 of the metal specimen block 200, where it will interface with the specimen block opening 204 ( Figures 3 to 4)Connection) and different internal porous regions 300B with different porosities, for example, away from the edge 308. In this way, the brazing material 360 will be distributed in each porous region in a different manner, resulting in different physical properties of the metal specimen block 200 in its different regions. More specifically, any number of different porous regions and / or sub-regions can be used to form at least one different physical property in the component 202 including the metal specimen block 200, such as: joint adhesive bond strength, stress / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness, and mass. In a non-exhaustive list of possibilities, compared with other solid regions of the metal specimen block 200, the metal specimen block 200 can include a higher porosity in one porous region to guide more brazing material therein by capillary action, thereby controlling at least one physical property of the component 202. In another embodiment, compared with other solid regions of the metal specimen block 200, the metal specimen block 200 can include a lower porosity in one porous region to guide less brazing material therein by capillary action, thereby controlling at least one physical property of the component 202. In other embodiments, the metal specimen block 200 can include two or more porous regions that together constitute the entire metal specimen block 200. Any arrangement of the porous regions and / or sub-regions can result in the desired flow and penetration of the brazing material 360.

[0085] In certain embodiments, additive manufacturing may also include forming any kind of improvement to the component 202, including (for example) structures that did not previously exist in the removed damaged portion. For example, as Figure 8B shown, the additive manufacturing may optionally include forming cooling channels 380 in the metal specimen block 200. The cooling channels 380 can extend through the metal specimen block 200 in any way, such as extending in a meandering path in the metal specimen block or extending through the outer surface 306 of the metal specimen block 200. In another example, for example, as Figure 8B shown, the additive manufacturing may optionally include forming one or more support and / or cooling structures 382 (e.g., pins / fins) in the metal specimen block 200 (possibly with cooling channels (not shown) therein). Any advantageous internal structural changes can be made to the metal specimen block 200. Any currently known or later developed post-additive manufacturing finishing processes can optionally be performed on the metal specimen block 200, such as grinding to smooth its surface and blend its surface. Advantageously, the teachings of the present disclosure can eliminate the need for other finishing steps (e.g., shot peening, heat treatment, hot isostatic pressing (HIP), etc.) that are typically used to address residual stresses present in materials after additive manufacturing. Figure 9BIllustrated is the insertion of a first brazing material 328 into a first cavity 320 through a second conduit 322. The first brazing material 328 may be introduced into the first cavity 320 through the second conduit 322 in any presently known or later developed manner (after additive manufacturing of the metal specimen block 200), e.g., forced air flow, gravity feed, vibratory feed, etc. The first brazing material 328 may include any of the brazing materials listed below. The first brazing material 328 may be introduced into the first cavity 320 in a controlled atmosphere, e.g., in a non-reactive gas (such as but not limited to argon and / or nitrogen). As noted, the first brazing material 328 may be in powder form or non-powder form, such as a paste made from powder and a binder (e.g., Braz-Binder Gel available from Vitta). In any case, a barrier member 332 retains the brazing material 328 within the first cavity 320. The insertion may also include performing a heat treatment to diffuse elements that lower the melting temperature of the brazing material 328 into the barrier member 332, as described herein.

[0086] Figure 9C Illustrated is separating the second conduit 322 from the exterior of the AM metal member 290. That is, once the first brazing material 328 is located within the first cavity 320, a seal member 330 is formed to seal the second conduit 322. As noted, the seal member 330 may include any structure capable of closing the second conduit 322 at or near the outer surface 306 of the AM metal member 290, i.e., after the first brazing material 328 has been introduced into the first cavity 320 through the second conduit 322. For example, the seal member 330 may include a plug or weld in the second conduit 322 at or near the outer surface 306 of the AM metal member 290.

[0087] Figure 9D and Figure 9E Illustrated is positioning the metal specimen block 200 within a specimen block opening 204 in a body 206 of a component 202. The metal specimen block 200 may be positioned within the specimen block opening 204 in the body 206 in any presently known or later developed manner (e.g., using a robotic arm or manually). If necessary, the metal specimen block 200 may be held in place by any desired means, e.g., an adhesive, a male-female connector 354 ( Figure 7B ), clamps, etc. Figures 9E to 9G Also illustrated is infiltrating the metal specimen block 200 with a brazing material 360 to couple the metal specimen block within the specimen block opening 204 in the body 206, i.e., by performing a brazing process. Figures 10A to 10EShows an enlarged cross-sectional view of a metal specimen block 200 within a specimen block opening 204 of a body 206 of a component 202 according to an embodiment of the present disclosure and including a plurality of (used) brazing reservoirs 292. The brazing material 328 and / or 360 can include any currently known or later developed brazing composition, as described herein. The infiltration can include any currently 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 can include, for example, applying the brazing material 360 ( Figure 9D ) and applying heat ( Figure 9E ), thereby causing the brazing material to flow into, through, and around the metal specimen block 200 by capillary action.

[0088] The infiltration of the brazing material 360 is at least based on the characteristics of one or more porosities of the porous region 300. For example, as Figure 8B and Figure 10A shown, the infiltration can include causing the brazing material 360 to travel through and infiltrate the porous region 300. The porosity of the porous region 300 determines the flow pattern of the brazing material 360. For example, as Figure 8B and Figure 10B shown, the infiltration can include causing the brazing material 360 to travel through and infiltrate the external porous region 300A based on the characteristics of the first porosity of the external porous region 300A, and to travel through and infiltrate the second external porous region 300B based on the characteristics of the second porosity of the second external porous region. As Figure 8D and Figure 10B shown, in the case where a variable porosity sub-region 312 is present together with two or more porous regions 300A, 300B having different porosities, the brazing material 360 can travel through and infiltrate the variable porosity region 312 based on the characteristics of the variable porosity sub-region 312 (e.g., gradient of porosity, stepped porosity, etc.). As Figure 8D and Figure 10B shown, in the case where the variable porosity sub-region 312 includes an external porous region 300A and an internal porous region 300B and is located therebetween, the infiltration can include causing the brazing material 360 to travel through and infiltrate the external porous region 300A based on the characteristics of the first porosity of the external porous region 300A, to travel through and infiltrate the variable porosity sub-region 312 between regions 300A to 300B based on the characteristics of the variable porosity region 312 (e.g., gradient of porosity, stepped porosity, etc.), and to travel through and infiltrate the internal porous region 300B based on the characteristics of the second porosity of the internal porous region 300B.

[0089] Options for different porosities in the porous region 300 result in different flow and penetration of the brazing material 360. Due to the brazing process, the porous region 300 or sub-regions with different porosities in which the brazing material 360 is present can have at least one different physical property. In one example, as Figure 8D and Figure 10B shown, the porosity of the first outer porous region 300A can be higher (i.e., lower density) than the porosity of the second inner porous region 300B. In such a case, penetration includes penetrating the first outer porous region 300A with more brazing material 360 than the second inner porous region 300B. Depending on the brazing material 360 used, among other factors, different porosities allow customization of at least one physical property 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 mass. Additionally, compared to conventional narrow-gap fill brazing processes and due to the strict manufacturing tolerances required for narrow-gap brazing, the multiple flow paths of the brazing material using the porous region 300 can reduce the likelihood of lack of fill and / or voids along the brazed joint.

[0090] In certain embodiments, different brazing materials 360 can be used in different parts of the metal specimen block 200, thereby providing further customization of the connection of the metal specimen block 200 in the component 202. For example, referring to Figure 10C , the brazing material 360A can be used on the first metal part or side 326 of the component 202, and another brazing material 360B different from the brazing material 360A can be used on a different part or side 327 of the component 202. In one example, referring to Figure 3 , Figure 4 and Figures 10A to 10D , the first metal part or side 326 of the component 202 can be the first (concave pressure) side outer walls 152, 178 of the airfoils 150, 176, and the second or side 327 of the component 202 can be the second (convex suction) side outer walls 154, 180 of the airfoils 150, 176. In addition to the different porous regions 300, the different brazing materials 360A, 360B on the different parts or sides 326, 327 can be customized for the expected environment of the component 202 at those locations. As will be appreciated, the number of variations of the brazing material and / or porous region / sub-region is very large, making it possible to address a wide variety of difficult repair situations.

[0091] In addition to the penetration of the brazing material 360 described above to connect the metal specimen block 200 in the specimen block opening 204, the embodiments of the present disclosure also use a brazing reservoir 292 to provide additional brazing material 328(342) to the brazing region 294 in favorable circumstances. As noted,Figures 10A to 10E Some examples of the brazing reservoir 292 in the metal specimen block 200 are shown. Figure 11 A partial perspective view of an exemplary component 202 (e.g., an airfoil as in Figures 3 to 4 ) including the brazing reservoir 292 is shown. The brazing reservoir 292 can be used simultaneously with the penetration of the brazing material 360 described above to couple the metal specimen block 200 to the specimen block opening 204, or can be used later during the use of the component 202 having the metal specimen block 200 therein, e.g., to repair a damaged area 348. The brazing reservoir 292 is used by heating the AM metal member 290 to a predetermined temperature above the melting temperature of the first brazing material 328, thereby liquefying the first brazing material 328 and opening the barrier member 332, and the liquefied first brazing material 328 flows through the first conduit 324 to penetrate the brazing area 294. The liquefied first brazing material 328 flows under a pressure increased based on the pressure in the first chamber 320 generated by heating. The pressurized and liquefied first brazing material 328 can thus penetrate various brazing areas 294 that typically cannot receive the liquefied brazing material 360 entering by gravity and / or capillary action.

[0092] Figures 10A to 10E and Figure 11 A view shows the liquefied first brazing material 328 flowing through the first conduit 324 (or partially solidifying in the first conduit 324). Some of the first brazing material in the first brazing material 328 can also remain in the first chamber 322, i.e., after its solidification. However, in response to the metal specimen block 200 or the body 206 exceeding a predetermined temperature, the first chamber 320 is at least a partially open space. In the case of using the second brazing material 342, this predetermined temperature can also exceed the melting temperature of the second brazing material. The predetermined temperature can be selected to be within the range of the heat used to couple the metal specimen block 200 in the specimen block opening 204 during the penetration step, or within the range experienced during the use of the component 202 (e.g., when a damaged area 348 is expected). The predetermined temperature can be controlled by controlling the composition of the first brazing material 328 and / or the barrier member 332 and the physical configuration of the barrier member 332 (e.g., thickness, width, chemical composition, etc.). When the predetermined temperature of the metal specimen block 200 or the component 202 (depending on which the brazing reservoir 292 is located in) exceeds the melting temperature of the first brazing material 328, the barrier member 332 opens the fluid communication through the first conduit 324. For example, as Figure 11 shown, in response to the body 206 exceeding this predetermined temperature, the first brazing material 328 liquefies, so that the liquefied first brazing material 328 (possibly with some material of the barrier member 332 therein) flows through the first conduit 324 to penetrate the brazing area 294, and this brazing area is in Figure 11The damaged area 348 is shown therein. When used in the body 206 of the component 202, the brazing reservoir 292 can provide self - repair for internal cracks, for example, during the use of the component or during heat treatment, without additional processing. As Figure 7D shown, in the case where the second cavity 340 is defined in the metal specimen block 200 or the body 206 (i.e., in the first conduit 324 between the first cavity 320 and the brazing area 294), the second brazing material 342 therein is different from the first brazing material 328. Here, the liquefied first brazing material 328 flows through the first conduit 324 and mixes with at least a part of the second brazing material 342, so that the mixed liquefied first brazing material 328 and the second brazing material 342 penetrate the brazing area 294. It should be noted that the second brazing material 342 may have a melting temperature higher than that of the first brazing material 328, so a temperature higher than the predetermined temperature is required to melt it. In this case, some of the second brazing material 342 will liquefy, some of the second brazing material 342 will be entrained into the brazing area 294 by flowing (mixing with the liquefied first brazing material 328), and some of the second brazing material 342 will be left.

[0093] As pointed out, the brazing area 294 can take various forms. Figures 10A to 10E and Figure 11 Some examples of the brazing area 294 are shown. For the component 202, for example, the brazing area 294 can include at least one of the following: the contact interface 346 between the specimen block opening 204 in the body 206 and the metal specimen block 200 in the specimen block opening 204, the porous area 300 at least partially located in at least one of the body 206 and the metal specimen block 200, and at least one of a part of the body 206 and the outer surface 334. For the metal specimen block 200, for example, the brazing area 294 can include at least one of the following: the porous area 300 in the AM metal member 290, the contact interface 346 between the metal specimen block 200 and the specimen block opening 204 in the body 206 of the component 202 in which the metal specimen block 200 is located, and a part or the outer surface 334 of the body 206 of the component 202 in which the metal specimen block 200 is located. In the case where the brazing area 294 includes the porous area 300, the porous area can be the same as the porous area penetrated by the brazing material 360, or another porous area 300 separated from the porous area penetrated by the brazing material 360. Figure 10A An example where the porous area 300 is the same for two brazing processes is shown. In this example, one or more brazing reservoirs 292 can be used to provide additional brazing material 360 (and possibly also 342) to the porous area 300 that the brazing material 328 may not be able to reach.Figure 10D An embodiment is shown in which a brazing reservoir 292 is used to provide brazing material 328 to a porous region 300E, which is different from the porous regions 300A, 300B for joining the metal specimen block 200 to the specimen block opening 204. The porous region 300E may be located at a position where high stress may occur, for example, due to a predetermined temperature or other reasons. Here, when a predetermined temperature is reached, the first brazing material 328 may provide additional strength and / or stability during the use of the component 202. Any porous region 300 served by the brazing reservoir 294 may have a variable porosity, where two or more porous regions or sub-regions have different porosities, see, for example Figure 8D . It should be understood that the porous region 300E as Figure 10D shown may alternatively be a solid region where high stress may cause cracking, and the solid region may be filled and stabilized by the first brazing material 328. Figure 10B An example is shown in which the brazing region 294 is the contact interface 346 (joint 384) between the metal specimen block 200 and the specimen block opening 204 of the body 206 of the component 202, and the first brazing material 328 is located in the joint 384. Figure 10C The brazing region 294 is shown as a damaged region 348 (e.g., a crack) within the solid region of the metal specimen block 200. Although specific brazing regions 294 have been shown herein, it should be emphasized that the brazing region 294 may include other structures and / or features not described herein.

[0094] Certain embodiments of the method may include removing the brazing reservoir 292 from the metal specimen block 200 or the body 206 of the component 202 after heating (i.e., after its use). Referring to Figure 8E and Figure 10E , in certain embodiments, the brazing reservoir 292 may be disposed in a removable section 370 of the metal specimen block 200 or the body 206 of the component 202. Figure 8E and Figure 10E A metal specimen block 200 is shown that includes a section 370 of the AM metal member 290 of the metal specimen block 200, which can be removed later once the brazing reservoir 292 has been used. That is, the section 370 is provided for the primary purpose of setting the brazing reservoir 292, but otherwise it is not essential for the component 202 or the metal specimen block 200. As Figure 10E shown, once the brazing reservoir 292 has been used, the section 370 of the AM metal member 290 in which the brazing reservoir is located can be removed, for example, by grinding, electrical discharge machining, etc. In Figure 10EIn this case, the section 370 above the horizontal virtual line will be removed. The remaining section 372 of the AM metal component 290 may not include any part of the brazing reservoir 292. For example, by forming the brazing reservoir 292 in a section of the component 202 that is not required for the completed component 202 and removing that section after the brazing reservoir 292 has been used, a similar method can be applied to the component 202.

[0095] Other embodiments of the method according to the present disclosure may include forming only one or more metal specimen blocks 200 for repairing the component 202. In such a case, as Figure 9A shown, the method includes forming a model of the specimen block opening 204 in the body 206 of the component 202 and performing additive manufacturing on the metal specimen blocks 200 as described herein.

[0096] Optionally, any currently known or later developed post-manufacturing finishing processes may be performed on the metal specimen blocks 200, such as, for example, shot peening, heat treatment, hot isostatic pressing (HIP), etc. Figure 9G Illustrative optional finishing steps for the component 202 are shown, such as but not limited to machining, to provide a seamless transition of the surface of the component 202 at the location where the metal specimen blocks 200 are added. However, as noted, the teachings of the present disclosure may eliminate the need for other finishing steps (such as, for example, shot peening, heat treatment, hot isostatic pressing (HIP), etc.) that are typically used to address residual stresses present in the material after additive manufacturing.

[0097] Embodiments of the present disclosure also include methods of using a brazing reservoir 292 in a component 202. Here, the method may include performing additive manufacturing on the body 206 of the component 202 that includes the brazing reservoir 292. Figure 3 、 Figure 4 and Figure 11 An illustrative component 202 including the brazing reservoir 292 is shown (e.g., as Figures 3 to 4View of the airfoil). The brazing reservoir 292 may include the same structure as the metal specimen block 200 described herein. That is, the brazing reservoir 292 may include: a first cavity 320 located in the body 206 (not the AM metal member 290); a second conduit 322 fluidly connecting the first cavity 320 to the outer surface 334 of the body 206; and a first conduit 324 fluidly connecting the first cavity 320 to the brazing area 294. The brazing area 294 may include at least one of the following: a porous area 300 in the body 206 (which may optionally include a variable porosity area having two or more sub-porous areas with different porosities), a contact interface 346 between the body 206 and the metal specimen block 200 in the specimen block opening 204 in the body 206, at least one of a portion of the body 206 or the outer surface 334, and a damaged area 348 in the body 206. The brazing reservoir 292 further includes: a first brazing material 328 located in the first cavity 320; and a sealing member 330 that separates the second conduit 320 from the exterior of the body 206. After the component 202 is additively manufactured, the first brazing material 328 is introduced into the first cavity 320 through the second conduit 322. Once the first brazing material 328 is located in the first cavity 320, a sealing member 330 is formed to seal the second conduit 322. The brazing reservoir 292 in the component 202 may further include a blocking member 332 that blocks fluid communication through the first conduit 324 between the first cavity 320 and the brazing area 294 before the blocking member 332 is exposed to a predetermined temperature that exceeds the melting temperature of the first brazing material 328. As described herein, the blocking member 332 includes a eutectic mixture of the metal material of the body 206 and the first brazing material 328. As will be described, the predetermined temperature of the heating step exceeds the melting temperature of the first brazing material 328. The additive manufacturing may optionally further include forming a second cavity 340 ( Figure 7D ) in the body 206 and in the first conduit 324 between the first cavity 320 and the brazing area 294, and filling the second cavity 340 with a second brazing material 342.

[0098] The body 206 of the component 202 may be heated to a predetermined temperature that exceeds the melting temperature of the first brazing material 328, causing the first brazing material 328 to liquefy and the blocking member 332 to open, and the liquefied first brazing material 328 (and any residue of the blocking member 332) to flow through the first conduit 324 to penetrate the brazing area 294. The heating may be sent during the manufacture of the component 202 to, for example, provide the first brazing material 328 to the porous area 300, thereby providing customized physical properties at that location, as described herein. In this case, as Figure 8E and Figure 10EAs shown, the brazing reservoir 292 can be removed from the body 206 after heating (i.e., after providing brazing material to the brazing area 294 during manufacturing). In other embodiments, the heating occurs during use of the component 202, such as when the nozzle 126 or the blade 132 is used in the turbine 100 ( Figure 1 ). Here, the brazing reservoir 292 can be used to address damaged areas 348 that occur during use, such as areas of potential high stress, oxidation, etc. Penetrating the brazing area 294 with the first brazing material 328 can extend the life of the component 202. In the case where a second brazing material 342 is provided in the second chamber 340, when the liquefied first brazing material 328 flows through the first conduit 324, it mixes with at least a portion of the second brazing material 342, and the mixed liquefied first brazing material 328 and second brazing material 342 penetrate the brazing area 294. As noted, the second brazing material 342 can have a melting temperature higher than that of the first brazing material 328, such that a temperature higher than a predetermined temperature is required to melt it. In this case, some of the second brazing material in the second brazing material 342 will liquefy, some of the second brazing material in the second brazing material 342 will be entrained into the brazing area 294 by flowing (mixing with the liquefied first brazing material 328), and some of the second brazing material in the second brazing material 342 will be left.

[0099] Figure 3 、 Figure 4 、 Figures 10A to 10E and Figure 11 show embodiments of an additive manufacturing (AM) component 202 including a used brazing reservoir 292 according to embodiments of the present disclosure. In this case, the component 202 includes the solidified first brazing material 328 in the brazing area 294, regardless of the form the brazing area 294 takes. Figures 10A to 10E and Figure 11 show the liquefied first brazing material 328 flowing through the first conduit 324 (or partially solidifying in the first conduit 324). Some of the first brazing material in the first brazing material 328 can also remain in the first chamber 322, i.e., after its solidification. However, in response to the metal specimen block 200 or the body 206 exceeding a predetermined temperature, the first chamber 320 is at least partially open space, i.e., in the metal specimen block 200 in the specimen block opening 204 of the body 206 or in the body 206.

[0100] Referring Figures 10A to 10E , the component 202 includes a body 206. As noted herein, the body 206 can have any form for a particular industrial application in which the component 202 is used. In the example used herein, the body 206 is for a turbine rotating blade 132 ( Figure 3 ) or a turbine stationary nozzle 126 (Figure 4 )。 Although the metal specimen block 200 is shown in Figure 3 and Figure 4 as being in the airfoils 150, 176 of the vane 132 and the nozzle 126 respectively, the metal specimen block 200 can be in any part of the body 206 of the component 202. The component 202 also includes an additive manufacturing (AM) metal specimen block 200 having a used brazing reservoir 292. The brazing material 360 couples the metal specimen block 200 in the specimen block opening 204 in the body 206 and can penetrate the porous region 300.

[0101] As Figure 10A shown, the brazing material 360 includes a first segment 390 that penetrates into the porous region based at least on the characteristics of the first porosity of the porous region 300. As Figure 10B shown, the brazing material 360 includes a first segment 390 that penetrates into the first porous region 300A, and the metal specimen block 200 also includes a second (internal) porous region 300B having a second porosity different from the first porosity. The first porosity can differ from the second porosity in at least one of the following characteristics: percentage of open space volume in the total volume, pore shape, pore size, pore number, and pore connectivity. The “at least one characteristic” of the porosity indicates that the porosity can result in different penetration characteristics, such as brazing material volume, in-porosity 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 format and arrangement of the metal specimen block 200. The body 206 can have a third porosity different from both the first porosity and the second porosity. For example, the body 206 can have a third porosity that is denser than both the first porosity and the second porosity, for example, it can be 100% solid. Optionally, the metal specimen block 200 can include a variable porosity region 312 having two or more porous sub-regions (for clarity, the sub-regions are only shown by the dashed boxes in Figure 10B ) located between the first outer porous region 300A and the second inner porous region 300B (and possibly including a part of them). The variable porosity region 312 can gradually change the porosity between the first porosity and the second porosity, for example, in a stepped or increasing manner. For example, as shown in, for example, Figure 8DAs shown, the porosity of the porous region 300 can increase in defined steps (via the porous sub-regions) from the inner region towards the outer surface 306 of the metal specimen block 200. As described herein, in some cases, the porosity of the porous region 300 can increase towards the outer surface 306 of the metal specimen block 200, such that, for example, more brazing material 360 is in the more outer porous regions (e.g., 300A) of the metal specimen block 200 in the component 202.

[0102] In Figure 10B it, the brazing material 360B includes a second section 392 that penetrates into the second porous region 300B based at least on the characteristics of the second porosity. As a result of the different porosities, the first porous region 300A and the second porous region 300B having the brazing material 360 therein have at least one different physical characteristic. Since the porosity can affect those physical characteristics, the porosity can be customized to select those physical characteristics. In one example, the first porosity of the first porous region 300A can be higher (i.e., lower density) than the second porosity of the second porous region 300B, and the first porous region 300A includes more brazing material 360 (328, 342) therein than the second porous region 300B. As Figure 10B shown, the first porous region 300A can be adjacent to the outer surface 306 of the metal specimen block 200 having a higher porosity than the second (inner) porous region 300B, and the porous region 300A includes more brazing material therein than the porous region 300B. In another example, as Figure 10B shown, the first porous region 300A is located in at least a portion of the edge 308 of the metal specimen block 200 that is configured to be joined to the body 206. As Figure 10B shown, such an arrangement can advantageously place more brazing material 360 (328, 342) near the brazed joint 384 to enhance the joint adhesive bond strength of the metal specimen block 200 in the specimen block opening 204 in the body 206 of the component 202, or it can allow less oxidation at the brazed joint 384 or greater thermal conductivity at the brazed joint 384. Any of the physical characteristics described herein can also be customized based on different porosities and / or different brazing materials. As noted, depending on the brazing material 360 (328, 342) used, different porosities can allow customization of the physical characteristics 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 mass. As noted, the metal specimen block 200 can have a near-net shape of the specimen block opening 204 in the body 206 of the component 202.

[0103] Although specific locations of different porous regions 300 and / or sub-regions have been illustrated herein, it should be emphasized that these different porous regions or sub-regions can be arranged in any manner to provide different braze material penetration characteristics and different physical characteristics of the component 202.

[0104] As Figures 1 to 2 shown, embodiments of the present disclosure may also include a turbine 100 that includes a turbine assembly 110 and at least one component 202, as described herein. The component 202 may take the form of a turbine stationary nozzle 126, a turbine rotating blade 132, or other components of the turbine 100. The metal specimen block 200 may be used in newly manufactured components or repaired components.

[0105] The present disclosure provides various technical and commercial advantages, examples of which are discussed herein. For repair, additive manufacturing allows for cost-effective generation of metal specimen blocks with custom-fitted shapes where only damaged material needs to be removed. The porous regions or sub-regions may provide a higher percentage of the base metal alloy (e.g., >60%) in certain zones, which can result in improved physical characteristics compared to, for example, pre-sintered preforms. The porous regions or sub-regions may also provide a welded / fused particle matrix filled with braze material (e.g., having a superalloy metal matrix) that is stronger compared to conventional metal particles surrounded by the material being brazed. The multiple flow paths of the braze material using multiple porous regions or sub-regions can also reduce the likelihood of lack of fill and / or voids along the braze joint compared to conventional narrow-gap fill brazing processes. The porous regions or sub-regions can be formed to have varying porosity / density across the metal specimen block to allow for highly customized braze material flow. The porous regions or sub-regions also accommodate larger joint gap size variations compared to machined solid specimen blocks with narrow gaps for the braze material. Additionally, the braze reservoir provides liquefied braze material to hard-to-reach zones and is capable of providing motive force to various braze regions (e.g., porous regions, cracks, and interfaces between the specimen and the component body). The pressurized and liquefied braze material from the braze reservoir can penetrate various braze regions that typically cannot admit liquefied braze material through gravity and / or capillary action. When used in the body of a component, the braze reservoir can also provide self-repair during use of the component or during heat treatment, for example, for internal cracks, without additional processing.

[0106] As used throughout the specification and claims, approximate language may be used to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function associated therewith. Accordingly, a value modified by a term or terms such as "about," "approximately," and "substantially" is not to be limited to the precise value specified. In at least some instances, the approximate language may correspond to the precision of the instrument used to measure the value. Herein and throughout the specification and claims, range limitations may be combined and / or interchanged; unless the context or language indicates otherwise, these ranges are recognized and include all the subranges contained therein. The use of "about" or "approximately" with respect to a particular value applied to a range applies to both end values thereof and may indicate, unless otherwise dependent on the precision of the instrument used to measure the value, + / - 10% of the stated value.

[0107] All structural, material, acts, and equivalents of the means or step plus function elements in the claims below are intended to include any structural, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or to limit the disclosure to the forms disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A method, the method comprising: additively manufacturing a metallic specimen block (200) in an opening (204) of a specimen block for inserting a component (202) into a body (206), the metallic specimen block (200) comprising an additively manufactured (AM) metallic component having a brazing reservoir (292), the brazing reservoir comprising: a first cavity (322) defined in the AM metallic component (290); a first conduit (324) defined in the AM metallic component (290) and fluidly coupling the first cavity (322) to a brazing region (294); and a blocking member (332) extending across the first conduit (324) to block fluid communication between the first cavity (322) and the brazing region (294); inserting a first brazing material (328) into the first cavity (322); isolating the first cavity (322) from the exterior of the AM metallic component (290); positioning the metallic specimen block (200) in the opening (204) of the specimen block (200); and heating the AM metallic component (290) to a predetermined temperature above the melting temperature of the first brazing material (328), such that the first brazing material (328) liquefies and the blocking member (332) opens, and the liquefied first brazing material (328) flows through the first conduit (324) to penetrate the brazing region (294).

2. The method according to claim 1, wherein the AM metallic component (290) comprises a porous region (300, 312) having a porosity, and the method further comprises applying a second brazing material (342) different from the first brazing material (328) to at least the AM metallic component (290), and wherein the heating causes the second brazing material (342) to penetrate into at least the porous region (300, 312) at least based on the characteristics of the porosity of the porous region (300, 312) to couple the AM metallic component (290) in the opening (204) of the specimen block (200).

3. The method according to claim 1, wherein the blocking member (332) comprises a eutectic mixture of the metallic material of the AM metallic component (290) and the first brazing material (328), and wherein the predetermined temperature exceeds the melting temperature of the first brazing material (328).

4. The method according to claim 1, wherein the additive manufacturing further comprises additive manufacturing a second cavity (340) in the AM metal component (290) and the first conduit (324) between the first cavity (320) and the brazing region (294), and filling the second cavity (340) with a second brazing material (342), wherein the liquefied first brazing material (328) flows through the first conduit (324) and liquefies the second brazing material (342), and wherein the liquefied first brazing material (328) and the liquefied second brazing material (342) penetrate the brazing region (294).

5. The method according to claim 1, wherein the brazing region (294) comprises at least one of the following: a porous region (300, 312) in the AM metal component (290), a contact interface (346) between the metal specimen block (200) and a specimen block opening (204) in the body (206) of the component (202) in which the metal specimen block (200) is located, and a part or outer surface (306, 334) of the body (206) of the component (202) in which the metal specimen block (200) is located.

6. The method according to claim 5, wherein the porous region (300, 312) has a variable porosity, and wherein two or more sub-porous regions have different porosities.

7. The method according to claim 1, the method further comprising removing the brazing reservoir (292) from the metal specimen block (200) after the heating.

8. The method according to claim 1, wherein the additive manufacturing comprises forming a second conduit (322) defined in the AM metal component (290) and fluidly coupling the first cavity (322) to an outer surface (306, 334) of the AM metal component (290), and separating the first cavity (322) from the exterior of the AM metal component (290) includes sealing the second conduit (322).

9. A method, the method comprising: additively manufacturing a body (206) of a component (202), the body (206) comprising a brazing reservoir (292), the brazing reservoir comprising: a first cavity (322) defined in the body (206); a first conduit (324) defined in the body (206) and fluidly coupling the first cavity (322) to a brazing region (294); and a blocking member (332) extending across the first conduit (324) to block fluid communication between the first cavity (322) and the brazing region (294); inserting a first brazing material (328) into the first cavity (322); separating the first cavity (322) from the exterior of the body (206); and Heat the body (206) to a predetermined temperature above the melting temperature of the first brazing material (328), so that the first brazing material (328) liquefies and the blocking member (332) opens, and the liquefied first brazing material (328) flows through the first conduit (324) to penetrate the brazing area (294).

10. The method according to claim 9, wherein the blocking member (332) comprises a eutectic mixture of the metallic material of the body (206) and the first brazing material (328), and wherein the predetermined temperature exceeds the melting temperature of the first brazing material (328).

11. The method according to claim 9, wherein the additive manufacturing further comprises additive manufacturing a second cavity (340) in the body (206) and the first conduit (324) between the first cavity (322) and the brazing area (294), and filling the second cavity (340) with a second brazing material (328), wherein the liquefied first brazing material (328) flows through the first conduit (324) and mixes with at least a portion of the second brazing material (342), and wherein the mixed liquefied first brazing material (328, 360, 360A, 360B) and the second brazing material (342) penetrate the brazing area (294).

12. The method according to claim 9, wherein the brazing area (294) comprises at least one of the following: a porous area (300, 312) in the body (206), a contact interface (346) between the body (206) and a metal specimen block (200) in an opening (204) of the specimen block (200) in the body (206), at least one of a portion of the body (206) and an outer surface (306, 334), and a damaged area (348) in the body (206).

13. The method according to claim 12, wherein the porous area (300, 312) has a variable porosity, and wherein two or more porous sub-areas have different porosities.

14. The method according to claim 9, wherein the heating occurs during use of the component (202).

15. The method according to claim 9, wherein the additive manufacturing comprises forming a second conduit (322) defined in the body (206) and fluidly coupling the first cavity (322) to an outer surface (306, 334) of the body (206), and separating the first cavity (322) from the exterior of the body (206) includes sealing the second conduit (322).

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