Metallic porous region for component printed on replacement region or substrate region of component

Abstract

A component (202) includes a dense base region (204), a dense replacement region (206), and an additive manufactured (AM) porous region (200) between the dense base region (204) and the dense replacement region (206). The porosity of the porous zone (200) is from 2% to 50% of the open space volume of the AM porous zone (200): total volume. The porous region (200) can be printed onto the base region (204) or the replacement region (206). A braze material (310) couples the base region (204), the porous region (200), and the replacement region (206) together and infiltrates into the porous region (200) based at least on a characteristic of the porosity. The porous regions (200) reduce stress at the junctions (370, 372) between the dense regions (204, 206) and can be tailored to create physical properties that differ from physical properties of only the base and replacement regions (204, 206).

Description

Technical Field

[0001] The present disclosure relates generally to component repair, and more particularly, to repairing a component using a metallic porous region printed onto a replacement region for a component or onto a base region of 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 many forms, such as turbine rotating blades or fixed guide vanes including airfoils that direct working fluid to create energy. The rotating blades are coupled to the turbine rotor and are used to rotate the turbine rotor, and the fixed guide vanes are coupled to the casing of the turbine to direct the working fluid toward the rotating blades.

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

[0004] However, the replacement porous area is made of the same material and external structure as the removed portion of the component. Therefore, the replacement porous area will suffer from some of the same shortcomings as the original component and / or the incision, and general performance characteristics such as porous area strength, oxidation resistance, cyclic fatigue, stress resistance / strain resistance, ductility, wear resistance, thermal conductivity or electrical conductivity and / or reduced quality are not improved. Use a single brazing material to connect the replacement porous area to the component, which can prevent the improvement of the general performance characteristics listed above and the additional performance characteristics related to the joint, such as increasing the joint adhesive bonding strength and reliability and reducing the required brazing post-processing / mixing. Use the same porous area as the removal incision in material also does not allow the reduction of the higher material cost for replacing the porous area, and may produce higher stress at the joint between the replacement area and the rest of the component. Summary of the invention

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

[0006] One aspect of the present disclosure provides a component comprising: a dense first zone; a dense second zone; an additively manufactured (AM) porous zone, wherein the additively manufactured (AM) porous zone is located between the dense first zone and the dense second zone, and the porosity of the AM porous zone is 2% to 50% of the open space volume of the AM porous zone: the total volume; and a brazing material, which connects the dense first zone, the AM porous zone and the dense second zone together, and the brazing material infiltrates into the AM porous zone at least based on the characteristics of the porosity.

[0007] Another aspect of the present disclosure includes any of the foregoing aspects, and the porosity of the AM porous zone varies along at least one of the length, width, and thickness of the AM porous zone between the dense first zone and the dense second zone.

[0008] Another aspect of the present disclosure includes any of the foregoing aspects, and the porosity is 10% to 40% of the open space volume of the AM porous region:total volume.

[0009] Another aspect of the present disclosure includes any of the foregoing aspects, and the AM porous region includes cooling channels in the AM porous region.

[0010] Another aspect of the disclosure includes any of the foregoing aspects, and the dense first region and the dense second region are solid materials.

[0011] Another aspect of the present disclosure includes a method for repairing a component, the method comprising: removing a region to be replaced from a dense base region of the component to leave a first surface on the dense base region; additively manufacturing a porous region on one of the first surface of the dense base region and the second surface of the dense replacement region, the porous region having a porosity of 2% to 50% of the open space volume of the porous region: the total volume; positioning the dense replacement region and the dense base region together with the porous region located between the dense replacement region and the dense base region; and infiltrating the porous region with a brazing material to connect the dense base region, the dense replacement region, and the porous region together.

[0012] Another aspect of the disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a porous region on a first surface of the dense base region, and the positioning includes positioning the dense replacement region on the porous region.

[0013] Another aspect of the present disclosure includes any of the aforementioned aspects, and the additive manufacturing includes forming a higher porosity in a first position at or near a third surface of the porous region contacting the dense replacement region than at a second position in the porous region closer to the first surface of the dense base region, wherein the infiltration includes infiltrating more brazing material into the porous region at the first position than at the second position.

[0014] Another aspect of the present disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a porous zone having a first component, the first component being configured to be lockingly engaged with a second component of a dense replacement zone, wherein the positioning includes lockingly engaging the porous zone and the dense replacement zone with the first component and the second component.

[0015] Another aspect of the disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming the porous region on the second surface of the dense replacement region, and the positioning includes positioning the porous region on the first surface of the dense base region.

[0016] Another aspect of the present disclosure includes any of the foregoing aspects, and additive manufacturing includes forming a higher porosity in a first position at or near a third surface of the porous zone contacting a first surface of the dense base zone than at a second position in the porous zone closer to a second surface of the dense replacement zone, wherein the infiltration includes infiltrating more brazing material into the porous zone at the first position than at the second position.

[0017] Another aspect of the present disclosure includes any of the foregoing aspects, and the additive manufacturing includes forming a porous region having a first component, the first component being configured to be lockedly engaged with a second component of a dense base region, wherein the positioning includes lockingly engaging the porous region and the dense base region with the first component and the second component.

[0018] Another aspect of the present disclosure includes any of the foregoing aspects, and the porous region and the dense replacement region jointly have the shape and size of the region to be replaced.

[0019] Another aspect of the disclosure includes any of the foregoing aspects, and the porosity of the porous zone varies along at least one of the length, width, and thickness of the porous zone between the dense replacement zone and the dense base zone.

[0020] Another aspect of the present disclosure includes any of the foregoing aspects, and the dense base region and the dense replacement region are solid materials.

[0021] Another aspect of the present disclosure includes any of the preceding aspects, and the additive manufacturing includes forming cooling channels in the porous region.

[0022] Another aspect of the present disclosure includes any of the preceding aspects, and the infiltrating includes using vacuum brazing, induction brazing, or inert gas atmosphere heating.

[0023] Another aspect of the disclosure includes any of the foregoing aspects, and additively manufacturing the porous region includes using a system with one or more melting beam sources to fuse layers of metal powder together and further includes adjusting parameters of the system to control the porosity of the porous region.

[0024] Another aspect of the present disclosure includes any of the foregoing aspects, and the adjusting parameter step includes at least one of the following operations: adjusting the overlap amount of the melting areas of one or more melting beam sources; adjusting the scanning speed; and adjusting at least one of the melting beam spot size, focus or power.

[0025] Another aspect of the present disclosure includes a method for repairing a component, the method comprising: removing a region to be replaced from a dense base region of the component to leave a first surface on the dense base region; additively manufacturing a porous region on the first surface of the dense base region and additively manufacturing a dense replacement region on the porous region, the porosity of the porous region being 2% to 50% of the open space volume of the porous region: the total volume; and infiltrating the porous region with a brazing material to fix the dense base region, the dense replacement region and the porous region together.

[0026] Another aspect of the present disclosure includes any of the aforementioned aspects, and the additive manufacturing includes forming a higher porosity in at least one of the following: a first segment of the porous zone closest to the dense replacement zone and a second segment of the porous zone closest to the dense substrate zone, wherein the infiltration includes infiltrating more brazing material into at least one of the first segment and the second segment than in the third segment of the porous zone.

[0027] Another aspect of the present disclosure includes any of the foregoing aspects, and the porous region and the dense replacement region together have a shape and size for replacing the region to be replaced.

[0028] Another aspect of the disclosure includes any of the foregoing aspects, and the porosity of the porous zone varies along at least one of the length, width, and thickness of the porous zone between the dense replacement zone and the dense base zone.

[0029] Another aspect of the present disclosure includes any of the foregoing aspects, and the dense base region and the dense replacement region are solid materials.

[0030] Another aspect of the present disclosure includes any of the preceding aspects, and the additive manufacturing includes forming cooling channels in the porous region.

[0031] Another aspect of the present disclosure includes any of the preceding aspects, and the infiltrating includes using vacuum brazing, induction brazing, or inert gas atmosphere heating.

[0032] Two or more aspects described in this disclosure (including those described in this summary) can be combined to form a specific implementation not specifically described herein. That is, all embodiments described herein can be combined with each other.

[0033] The details of one or more implementations are set forth in the drawings and description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the present disclosure taken in conjunction with the accompanying drawings which depict various embodiments of the present disclosure, wherein:

[0035] Figure 1 shows a schematic diagram of an illustrative industrial machine in the form of a gas turbine system and including components according to embodiments of the present disclosure;

[0036] Figure 2 Shows that Figure 1 A cross-sectional view of an exemplary gas turbine assembly for use with a gas turbine system in and including components according to an embodiment of the present disclosure;

[0037] Figure 3 shows a perspective view of a component in the form of a turbine rotating blade including a metal porous region according to an embodiment of the present disclosure;

[0038] Figure 4 shows a perspective view of a component in the form of a turbine nozzle including a metallic porous region according to an embodiment of the present disclosure;

[0039] Figure 5 shows a schematic block diagram of an exemplary additive manufacturing system for additively manufacturing a metallic porous region according to an embodiment of the present disclosure;

[0040] FIG. 6A to FIG. 6D shows a top view of a sample metallic porous region having porous regions with different porosities according to an embodiment of the present disclosure;

[0041] FIG. 7A to FIG. 7B A side view showing the removal of a to-be-replaced area from a remaining component according to various embodiments of the present disclosure;

[0042] FIG. 8A to FIG. 8E shows a side view of a method according to various other embodiments of the present disclosure;

[0043] 9A to 9F shows a side view of a method according to various embodiments of the present disclosure;

[0044] FIG. 10A to FIG. 10E shows a side view of a method according to various embodiments of the present disclosure; and

[0045] FIG. 11A to FIG. 11B A top view and a schematic side view of a metal porous region according to an embodiment of the present disclosure are respectively shown.

[0046] It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered to limit the scope of the present disclosure. In the drawings, like numbers represent like elements between drawings. DETAILED DESCRIPTION

[0047] First, in order to clearly describe the present disclosure, it will be necessary to select certain terms when referring to and describing relevant machine components within the exemplary application of the turbine. In doing so, if possible, common industry terms will be used and adopted in a manner consistent with their accepted meanings. Unless otherwise stated, such terms should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. A person of ordinary skill in the art will understand that several different or overlapping terms may be used to refer to a particular component. An object that may be described as a single part in this article may include multiple parts and be referenced as consisting of multiple parts in another context. Alternatively, an object that may be described as including multiple parts in this article may be referred to as a single part elsewhere.

[0048] In addition, several descriptive terms may be used regularly throughout this document, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise indicated, these terms, along with their definitions, are as follows. As used herein, "downstream" and "upstream" are terms that indicate the direction relative to the flow of a fluid, such as a working fluid through a turbine, or, for example, an air flow through a combustor or a coolant through one of the component systems of a turbine. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite to the flow. In the absence of any additional particularity, the terms "front" and "rear" refer to directions, with "front" referring to the front end or compressor end of a turbine, and "rear" referring to the rear end or turbine end of a turbine.

[0049] In addition, several descriptive terms may be used regularly herein, as described below. The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0050] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "one", "a kind of" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in the specification, the terms "include" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. "Optional" or "optionally" means that the event described subsequently may or may not occur, or the feature described subsequently may or may not exist, and the description includes instances where the event occurs or the feature exists and instances where the event does not occur or the feature does not exist.

[0051] Where an element or layer is referred to as being "on another element or layer," "engaged to another element or layer," "connected to another element or layer," "coupled to another element or layer," or "mounted to another element or layer," it may be directly on, engaged to, connected to, coupled to, or mounted to another element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to," there are no intervening elements or layers. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The verb forms "couple" and "mount" are used interchangeably herein.

[0052] As noted above, the present disclosure provides a component comprising a dense substrate region, a dense replacement region, and an additively manufactured (AM) porous region located between the dense substrate region and the dense replacement region. The porosity of the porous region is between 2% and 50% of the open space volume of the porous region: the total volume. The porous region can be printed onto the substrate region or the replacement region. The brazing material connects the substrate region, the porous region, and the replacement region together and infiltrates into the porous region based at least on the characteristics of the porosity. The method for repairing a component may include: removing the region to be replaced from the dense substrate region of the component to leave a first surface on the dense substrate region, and additively manufacturing the porous region on one of the first surface of the substrate region and the second surface of the replacement region. After positioning the substrate region and the replacement region together, the brazing material infiltrates the porous region to connect the substrate region, the replacement region, and the porous region together. In other embodiments, the porous region and the replacement region may be printed sequentially on the substrate region, and then the porous region may be infiltrated with the brazing material. The one or more pores of the porous zone are configured to guide the flow of one or more brazing materials in different ways to form physical properties different from those previously possible, for example by guiding more brazing materials when needed, guiding the brazing materials into special shapes and / or allowing the use of more than one brazing material. Customized porous zones do not suffer the same disadvantages as the original parts and / or cutouts and can be customized (with brazing materials) to, for example, change: joint adhesive bond strength, stress resistance / strain resistance, ductility, wear resistance, oxidation resistance, cyclic fatigue, thermal conductivity, electrical conductivity, surface roughness, hardness and quality. The repair is stronger than traditional narrow gap brazing processes, does not require specific post-repair finishing, and also provides improved physical properties compared to current technologies (such as pre-sintered preforms (PSP)). One or more brazing materials can be used to connect the replacement zone to the base zone, thereby also improving the performance characteristics associated with the joint (such as joint adhesive bond strength and reliability) and reducing the required post-braze processing / mixing. It is worth noting that the porous zone reduces the stress at the joint between the base zone and the replacement zone. The use of porous regions may also reduce material costs, for example by using less of more expensive material in the joint.

[0053] Figure 1A schematic diagram of an exemplary industrial machine that may include components according to the teachings of the present disclosure is shown. In this example, the machine includes a turbine 100 in the form of a combustion or gas turbine (GT) system. The turbine 100 includes a compressor 102 and a combustor 104. The combustor 104 includes a combustion zone 106 and a fuel nozzle assembly 108. The turbine 100 also includes a turbine assembly 110 and a common compressor / turbine shaft or rotor 112. In one embodiment, the turbine 100 is a 7HA.03 engine commercially available from GE Vernova. The present disclosure is not limited to any particular GT system and can be implemented in conjunction with other engines, including, for example, other HA, F, B, LM, GT, TM and E-class engine models of GE Vernova and engine models of other companies. In addition, the present disclosure is not limited to any particular turbine and can be applied to, for example, steam turbines, jet engines, compressors, turbofans, etc. In addition, the present disclosure is not limited to any particular turbine component and can be applied to any industrial component using a porous zone during manufacturing or repair.

[0054] In operation, air flows through compressor 102 and the compressed air is supplied to combustor 104. Specifically, the compressed air is supplied to a 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 connected to a fuel source ( Figure 2 The compressor 102 is fluidly connected to the rotor 112 (not shown) and delivers fuel and air to the combustion zone 106. The burner 104 is ignited and the fuel is burned. The burner 104 is fluidly connected to the turbine assembly 110 so that the gas flow thermal energy is converted into mechanical rotational energy. The turbine assembly 110 includes a turbine 111, which is rotatably coupled to the rotor 112 and drives the rotor. The compressor 102 is also rotatably coupled to the rotor 112. In the exemplary embodiment, there are multiple burners and fuel nozzle assemblies 108.

[0055] Figure 2 A turbine 100 ( Figure 1 ) is a cross-sectional view of an exemplary turbine assembly 110, which may be Figure 1100 is used together with the gas turbine system in the turbine assembly 100. The turbine 111 of the turbine assembly 110 includes a row of nozzles or guide vanes 120 coupled to the stationary housing 122 of the turbine 100 and an axially adjacent row 124 of rotating blades 132. The stationary guide vanes or nozzles 126 can be retained in the turbine assembly 110 by a radially outer platform 128 and a radially inner platform 130. A row 124 of blades in the turbine assembly 110 includes rotating blades 132, which are coupled to the rotor 112 and rotate with the rotor. The rotating blades 132 may include a radially inward platform 148 (at the root of the blade) coupled to the rotor 112 and an optional radially outward tip shroud 136 (at the tip of the blade). As used herein, the term "component" may collectively refer to the stationary nozzle 126, the rotating blade 132, or any other structure in which a metal coupon including a porous region according to the present disclosure may be employed.

[0056] Figure 3 and Figure 4 Illustrative components of a turbomachine in which the teachings of the present disclosure may be employed, such as hot gas path components, are shown. Figure 3 1 shows a perspective view of a turbine rotating blade 132 of the type in which embodiments of the present disclosure may be employed. The turbine rotating blade 132 includes a root 140 by which the rotating blade 132 is attached to the rotor 112 ( Figure 2 ). The root portion 140 may include a dovetail 142 configured to be mounted on the rotor 112 ( Figure 2 ) of the rotor wheel 144 ( Figure 2 ) in a corresponding dovetail groove in the periphery of the blade 132. The root 140 may also include a shank 146 extending between the dovetail 142 and a platform 148, which is disposed at the junction of the airfoil 150 and the root 140 and defines a portion of the inner boundary of the flow path through the turbine assembly 110. It will be appreciated that the airfoil 150 is a moving part of the rotating blade 132 that intercepts the working fluid 151 ( Figure 2 ) (i.e., hot combustion gases) and causes the rotor disk to rotate. It will be seen that the airfoil 150 of the rotating blade 132 includes a concave pressure side (PS) outer wall 152 and a circumferentially or laterally opposite convex suction side (SS) outer wall 154 extending axially between opposite leading edges 156 and trailing edges 158, respectively. The side outer walls 152 and 154 also extend in the radial direction from the platform 148 to the outboard tip 160, which may or may not include the tip shroud 136 ( Figure 2 ).

[0057] Figure 4 1 shows a perspective view of a stationary nozzle 126 of the type in which embodiments of the present disclosure may be employed. The stationary nozzle 126 includes an outer platform 170 by which the stationary nozzle 126 is attached to the stationary casing 122 ( Figure 2 The outer platform 170 may include any now known or later developed mounting configuration for mounting in a corresponding mounting in the casing. The fixed nozzle 126 may also include a nozzle for positioning between adjacent turbine rotor blades 132 ( Figure 3 ) and Platform 148( Figure 3 ) between the inner platform 174. The platforms 170, 174 define respective portions of the outboard and inboard boundaries of the flow path through the turbine assembly 110. It will be appreciated that the airfoil 176 is a movable component of the fixed nozzle 126 that intercepts the flow of the working fluid and directs the flow toward the turbine rotor blades 132 ( Figure 3 ) guide. It can be seen that the airfoil 176 of the fixed nozzle 126 includes a concave pressure side (PS) outer wall 178 and a circumferentially or laterally opposite convex suction side (SS) outer wall 180, which extend axially between opposite leading edges 182 and trailing edges 184, respectively. The side outer walls 178 and 180 also extend in the radial direction from the platform 170 to the platform 174.

[0058] It is understood that the bucket 132 or nozzle 126 may include internal cooling structures including a coolant source such as channels, ducts, and other structures that deliver coolant to its surface for film cooling. The coolant may include, for example, air from the compressor 102.

[0059] Embodiments of the present disclosure described herein may include aspects applicable to fixed nozzles 126, turbine blades 132, and / or any other industrial component that employs porous zones. The component may be, for example, a fixed nozzle 126, a blade 132, or any other industrial component that employs replacement zones. Figure 3 and Figure 4 Also shown is an exemplary additively manufactured (AM) porous region 200 (hereinafter referred to as "porous region 200" or "AM porous region 200") in the component 202. The porous region 200 is shown in dashed lines because, as will be explained, the porous region will be brazed by the brazing material 310 (in Figure 3 to Figure 4 The porous region 200 may be located between a dense base region 204 of the component 202 (i.e., the region remaining after the region to be replaced is removed) and a dense replacement region 206 of the component 202 (i.e., the region coupled to the base region 204 by the porous region 200 and the brazing material). In the example shown, the replacement region 206 includes Figure 3 At least a portion of the tip 160 of the rotating blade 132 or a corner of the tip 160 or Figure 4126 of the stationary nozzle 126. However, it should be emphasized that the porous region 200 can be used to couple any replacement region 206 of the component 202 to the base region 204 of the component 202. The replacement region 206 can be any portion of the component 202.

[0060] The additively manufactured porous region 200 can be additively manufactured using any now known or later developed technique capable of forming a porous metal on another part. In addition, the additively manufactured porous region 200 and the dense replacement region 206 can be additively manufactured using any now known or later developed technique capable of forming a porous metal on another part and forming a dense (e.g., solid) metal on the porous region 200. Figure 5 A schematic view / block diagram of an exemplary computerized metal powder additive manufacturing system 210 (hereinafter referred to as "AM system 210") for generating a porous region 200 or a plurality of porous regions 200A, 200B (a plurality is shown) and / or a dense replacement region 206 or a plurality of dense replacement regions 206A, 206B (a plurality is shown). Only a single layer of either region 200, 206 is shown. The teachings of the present disclosure will be described with respect to constructing a porous region 200 or replacement region 206 using a plurality of melt beam sources 212, 214, 216, 218, but it should be emphasized and will be readily appreciated that the teachings of the present disclosure are equally applicable to constructing a plurality of porous regions 200A, 200B (in a plurality) on a dense base region 204 using any number of melt beam sources. Figure 5 In the powder bed in the porous area 200) and / or constructing a plurality of replacement areas 206A, 206B (in Figure 5 204). 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 other forms of metal powder applications, such as selective laser melting (SLM) or metal cladding techniques (e.g., melting a metal source onto the surface of the dense base region 204). The porous regions 200A, 200B or replacement regions 206A, 206B are shown as rectangular elements; however, it should be understood that the additive manufacturing process can be easily adapted to manufacture porous or dense regions of any shape, a number of different porosity regions or sub-regions within a given porous region, or a number of different dense replacement regions or sub-regions within a given replacement region, and a large number of dense or porous regions on the build platform 220.

[0061] The AM system 210 generally includes an additive manufacturing control system 230 ("control system") and an AM printer 232. As will be described, the control system 230 executes a computer executable instruction set or code 234 to generate a dense area or a porous area using multiple melting beam sources 212, 214, 216, 218. In the example shown, the four melting beam sources may include four lasers. However, the teachings of the present disclosure are applicable to any melting beam source, such as an electron beam, a laser, etc. The control system 230 is shown as being implemented as a computer program code on a computer 236. To this extent, the computer 236 is shown to include a memory 238 and / or a storage system 240, a processor unit (PU) 244, an input / output (I / O) interface 246, and a bus 248. In addition, the computer 236 is shown to communicate with an external I / O device / resource 250. In general, the processor unit (PU) 244 executes the computer program code 234 stored in the memory 238 and / or the storage system 240. When executing computer program code 234, processor unit (PU) 244 can read and / or write data to / from memory 238, storage system 240, I / O device 250 and / or AM printer 232. Bus 248 provides a communication link between each of the components in computer 236, and I / O device 250 can include any device (such as keyboard, pointing device, display, etc.) that enables a user to interact with computer 236. Computer 236 only represents various possible combinations of hardware and software. For example, processor unit (PU) 244 can include a single processing unit or one or more processing units distributed across one or more locations (such as on a client and a server). Similarly, memory 238 and / or storage system 240 can reside at one or more physical locations. The memory 238 and / or storage system 240 may include any combination of various types of non-transitory computer-readable storage media, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), etc. The computer 236 may include any type of computing device, such as an industrial controller, a network server, a desktop computer, a laptop computer, a handheld device, etc.

[0062] As indicated, the AM system 210, and in particular the control system 230, executes code 234 to generate the porous region 200 or the dense replacement region 206. The code 234 may include, among other things, a computer executable instruction set 234S (also referred to herein as "code 234S") for operating the AM printer 232 and a computer executable instruction set 234O (also referred to herein as "code 234O") for defining the porous region 200 and / or replacement region 206 to be physically generated by the AM printer 232. As described herein, the additive manufacturing process begins with a non-transitory computer readable storage medium (e.g., memory 238, storage system 240, etc.) storing the code 234. The computer executable instruction set 234S for operating the AM printer 232 may include any now known or later developed software code capable of operating the AM printer 232.

[0063] The computer executable instruction set 2340 defining the porous region 200 and / or the replacement region 206 may include a precisely defined 3D model of the porous region and may be obtained from any of a number of well-known computer-aided design (CAD) software systems, such as DesignCAD 3D Max, etc.). In this regard, the code 234O may include any file format now known or developed later. In addition, the code 234O representing the porous area 200 and / or the replacement area 206 can be converted between different formats. For example, the code 234O may include a standard tessellation language (STL) file created for the stereolithography CAD program of the 3D system or an additive manufacturing file (AMF) as a standard of the American Society of Mechanical Engineers (ASME), which is 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 porous area 200 and / or the replacement area 206 can also be converted into a set of data signals as needed, and transmitted, received and converted into code, stored, etc. as a set of data signals. The code 234O can be configured according to the embodiments of the present disclosure to allow the formation of boundaries and internal sections in overlapping fields, as will be described. In any case, code 234O may be an input to AM system 210 and may come from a part designer, an intellectual property (IP) provider, a design company, an operator or owner of AM system 210, or from another source. In any case, control system 230 executes code 234S and 234O to divide porous region 200 and / or replacement region 206 into a series of thin slices that are assembled in successive layers of material using AM printer 232.

[0064] The AM printer 232 may include a process chamber 260 that is sealed to provide a controlled atmosphere for printing of the porous region 200. A build platform 220 on which the porous region 200 and / or the replacement region 206 may be built is positioned within the process 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 porous region 200 and / or the replacement region 206. Although four melt beam sources 212, 214, 216, 218 are shown, it should be emphasized that the teachings of the present disclosure are applicable to systems employing any number of sources (e.g., 1, 2, 3, or 5 or more). As is understood in the art, each melting beam source 212, 214, 216, 218 can have a field including a non-overlapping field region in which the melting beam source can exclusively melt the metal powder, and the melting beam source can include at least one overlapping field region in which two or more sources can melt the metal powder. In this regard, each melting beam source 212, 214, 216, 218 can generate a melting beam that fuses the particles for each slice, as defined by code 234O. For example, in Figure 5 In the figure, the melt beam source 212 is shown as forming a layer of the porous region 200 or the replacement region 206 using a melt beam 262 in one zone, while the melt beam source 216 is shown as forming a layer of the porous region 200 or the replacement region 206 using a melt beam 262' in another zone. Each melt beam source 212, 214, 216, 218 is calibrated in any manner now known or later developed. That is, each melt beam source 212, 214, 216, 218 has an expected position of its laser or electron beam relative to the build platform 220 related to the actual position of the laser or electron beam, so as to provide a separate position correction (not shown) to ensure its separate accuracy. In one embodiment, each of the plurality of melt beam sources 212, 214, 216, 218 can form a melt beam, such as 262, 262', having the same cross-sectional dimensions (e.g., shape and size in operation), power, and scanning speed.

[0065] Continue to refer Figure 5, the coater (or re-coater blade) 270 can form a thin layer of raw material 272 that is spread out as a blank canvas from which each successive slice of the porous region 200 or replacement region 206 will be formed. Various parts of the AM printer 232 can move to accommodate the addition of each new layer, for example, after each layer, the build platform 220 can be lowered and / or the chamber 260 and / or coater 270 can be raised. The process can use different raw materials in the form of fine-grained metal powders, and reserves of these raw materials can be maintained in the chamber 260 accessible by the coater 270. In the present case, the porous region 200 and / or the replacement region 206 can be made of metal, which can include pure metals or alloys. In one example, the metal may include nearly any non-reactive metal powder, i.e., non-explosive or non-conductive powder, such as, but not limited to: cobalt-chromium-molybdenum (CoCrMo) alloy; stainless steel; austenitic nickel-chromium based alloys, such as nickel-chromium-molybdenum-niobium alloy (NiCrMoNb) (e.g., Inconel 625 or Inconel 718); nickel-chromium-iron-molybdenum alloy (NiCrFeMo) (e.g., available from Haynes International, Inc. X); or a 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 alloy. The base region 204 may be made of the same or a different material and may be made by additive manufacturing or another process such as casting.

[0066] The processing chamber 260 is filled with an inert gas such as argon or nitrogen and is controlled to minimize or eliminate oxygen. The control system 230 is configured to control the flow of the gas mixture 274 from the inert gas source 276 in the processing chamber 260. In this case, the control system 230 can control the pump 280 and / or the flow valve system 282 for the inert gas to control the content of the gas mixture 274. The flow valve system 282 can include one or more computer-controllable valves, flow sensors, temperature sensors, pressure sensors, etc. that can accurately control the flow of a specific gas. The pump 280 may be provided with or without the valve system 282. In the case of omitting the pump 280, the inert gas can simply enter the conduit or manifold before being introduced into the processing chamber 260. The inert gas source 276 can be in the form of any conventional source for the material contained therein, such as a tank, a storage or other source. Any sensor (not shown) required for measuring the gas mixture 274 can be provided. The gas mixture 274 can be filtered in a conventional manner using a filter 286.

[0067] In operation, a build platform 220 having metal powder thereon is disposed within a process chamber 260, and a control system 230 controls the flow of a gas mixture 274 from an inert gas source 276 within the process chamber 260. As will be described herein, a base region 204 or a replacement region 206 is positioned within the metal powder, wherein the surface of the base region or replacement region is exposed to build a porous region 200 thereon. According to an embodiment of the present disclosure, the control system 230 also controls the AM printer 232, and in particular controls the coater 270 and the melting beam sources 212, 214, 216, 218 to sequentially melt the metal powder layers on the build platform 220, thereby generating a porous region 200 or a replacement region 206.

[0068] 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 specific additive manufacturing system or method. In addition, although the teachings of the present disclosure relate to the additively manufactured porous region 200 and / or replacement region 206, it will be appreciated that the component 202 (initial component) can be manufactured in any now known or later developed manner, such as by additive manufacturing (which may be similar to the additive manufacturing described for the porous region 200), casting, or other methods. The base region 204 and replacement region 206 for the component 202 can include any of the materials listed herein for the porous region 200.

[0069] As used herein, "porosity" is the ratio of the open space volume to the total volume of the structure being stated (e.g., porous zone 200). Typically, in this regard, porosity is stated as the volume of open space as a percentage of the overall volume or total volume of the structure being stated. Open space is an empty area in a solid material, and may be referred to herein as a "pore" 201, and may include interconnected channels in the material of the structure being stated. Therefore, a "porous zone" is an open space that is less than 100% solid and includes pores 201 and / or interconnected channels. As used herein, the three-dimensional boundary of a porous zone or sub-zone for the purpose of identifying its "total volume" can be determined by a porosity change greater than 2% within a porous zone 200 relative to an adjacent zone or sub-zone and / or the presence of an edge of a porous zone 200. "Open space volume" refers collectively to the empty three-dimensional space (i.e., voids, gaps, empty space) and / or unfilled material within a zone or sub-zone. As used herein, "different porosity" or "difference in porosity" generally refers to any kind of characteristics, such as: the percentage of open space volume to total volume, the number of pores 201 in a given volume, the volume (i.e., size) of pores 201, the shape of pores 201, and the variation of connecting channels between pores 201 (which may not be considered actual discrete pores) (referred to herein as "pore connecting channels"). As just one non-limiting example, the pore size may be, for example, 1.07×10 -6 to 8.58×10-3 Cubic millimeters (6.54×10 -11 to 5.24×10 -7 In the drawings, different porous zones or sub-zones are generally shown as continuous or in contact with each other, however, it should be emphasized that these porous zones or sub-zones can be isolated from each other in any manner, such as having solid areas between these porous zones or sub-zones. That is, a single metal specimen can include one or more isolated, non-contacting porous zones or sub-zones. It should be noted that the terms "zone" and / or "sub-zone" can be used interchangeably to represent changes in porosity. In the case of differences in, for example, pore shape or pore connecting channels, it will be recognized that the difference in porosity may not be based solely on the percentage of open space volume to total volume. However, in the case of comparing differences in porosity in terms of degree (e.g., higher or lower), the difference referred to is simply the difference in volumetric properties, i.e., the percentage of open space volume to total volume. As used herein, "dense" indicates that the material has a very low porosity (e.g., 1% or less) and can be a solid material, i.e., 0% porosity. Thus, a dense material has a porosity of less than 1% and does not allow the brazing material to penetrate the dense material. The base region 204 of the component 202 and the replacement region 206 for the component 202 are made of dense materials and can be solid materials. The material for the base region 204 or the replacement region 206 can be any of the materials listed herein for the porous region 200.

[0070] A porous metal coupon 200 having different porous regions with different porosities (which may or may not include one or more porous sub-regions with different porosities) may be formed using an AM system 210 as described herein or any other metal additive manufacturing system or method capable of forming porous metal. In terms of AM system 210 operation, the melting beam sources 212, 214, 216, 218 may be programmed to intermittently not sinter the metal to leave metal powder rather than solid material. This process may include overlapping the laser field regions by different amounts and / or designing the holes 302 into a build file, i.e., code 234O. Less overlap per laser scan forms a larger porosity, and more laser overlap between consecutive scans forms a smaller porosity. The laser spot size, scan speed, focal length, and power may also be controlled to adjust the porosity. More specifically, additive manufacturing includes using an AM system 210 having one or more melting beam sources 212, 214, 216, 218 to fuse together layers of metal powder, and adjusting parameters of the system to control the porosity of at least two porous regions. Adjusting the parameters may include at least one of the following operations: adjusting one or more melting beams 262, 262' (from sources 212, 214, 216, 218) Figure 5 ) of the melted regions; adjusting the system scan speed; and adjusting at least one of the melt beam spot size, focus, or power. When the unmelted metal powder is removed from the metal coupon 200, this leaves behind pores 302 with interconnecting channels between the pores 302 and forming one or more porous regions. In any case, the layered fabrication of the porous regions 200 can be controlled to form a desired porosity for any number, shape, and / or size of porous regions within any desired layer.

[0071] FIG. 6A to FIG. 6D A schematic top view of sample metal coupons 200 having different porosities is shown. Pores 302 are shown as darker open spaces in the figure. Fig. 6A The open space volume of a sample having a first porosity of approximately 40% is shown: the total volume of the sample porous region 200 (having a generally lower amount of open space and more or larger pores 302), Figure 6B The open space volume of a sample having a first porosity of about 30% is shown: the total volume of the sample porous area 200, Figure 6C The open space volume of a sample having a first porosity of about 20% is shown: the total volume of the sample porous area 200, Fig.6DA sample porous zone 200 (with a substantially lower amount of open space) is shown with a first porosity of approximately 10% of the sample's open space volume:total volume. Each porous zone may have a porosity of 2% to 50% of the porous zone's open space volume:total volume, with the porous zone being 2% to 50% open space and the other 50% to 98% solid. In other embodiments, each porous zone 300 may have a porosity of 10% to 40% of the open space volume:total volume, with the porous zone being 10% to 40% open space and the other 60% to 90% solid. In other embodiments, a porous region may be provided in the metal coupon 200 having a porous region in a range of less than 10%, in a range of less than 15%, in a range of less than 20%, in a range of less than 25%, in a range of less than 30%, in a range of less than 35%, in a range of less than 40%, in a range of less than 45%, in a range of 2% to 45%, in a range of 2% to 40%, in a range of 2% to 35%, in a range of 2% to 30%, in a range of 2% to 25%, in a range of 2% to 20%, in a range of 5% to 45%, in a range of 5% to 40%, in a range of 5% to 35%, in a range of 5% to 30%, in a range of 5% to 25%, In some embodiments, the present invention relates to a porosity within the range of 5% to 20%, within the range of 10% to 45%, within the range of 10% to 40%, within the range of 10% to 35%, within the range of 10% to 30%, within the range of 10% to 25%, within the range of 10% to 20%, within the range of 15% to 45%, within the range of 15% to 40%, within the range of 15% to 35%, within the range of 15% to 30%, within the range of 15% to 25%, within the range of 15% to 20%, within the range of 10% to 50%, within the range of 20% to 50%, within the range of 25% to 50%, within the range of 30% to 50%, within the range of 35% to 50%, within the range of 40% to 50%. Other ranges of porosity are also possible as will be described herein.

[0072] refer to Figure 3 , Figure 4 , FIG. 7A to FIG. 7B , FIG. 8A to FIG. 8E , 9A to 9F , FIG. 10A to FIG. 10E and FIG. 11A to FIG. 11B , embodiments of methods according to the present disclosure will now be described. The method may include repairing a component 202 . FIG. 7A to FIG. 7B , FIG. 8A to FIG. 8E , 9A to 9F and FIG. 10A to FIG. 10E Side views of various methods according to embodiments of the present disclosure are shown. Fig.11A and Fig. 11BA top view and a side view, respectively, of an exemplary porous zone 200 according to embodiments of the present disclosure are shown.

[0073] FIG. 7A to FIG. 7B The removal (i.e., cut) of a region 320 to be replaced from a dense base region 204 of a component (i.e., an initial component 202X to be repaired) is shown. The removal leaves a surface 322 on the dense base region 204. For uniformity of repair, particularly where multiple components 202X are undergoing similar types of damage repair, all base regions 204 may be cut to the same length. The region 320 to be replaced may have any form, but will typically include some form of defect 324 that will be corrected by replacing the region 320 with a new or undamaged replica. Figure 3 to Figure 4 In the example shown in , the area 320 may include a damaged tip 160 of a blade 132 or a damaged platform 174 of a nozzle 126. Alternatively, Figure 3 As shown in , the region 320 can be a smaller portion, such as the corner of the tip 160 of the blade 132. Defects 324 can take many forms, such as but not limited to: worn surfaces, pitting, oxidation, cracks and / or deformation. The region 320 can be removed using any now known or later developed removal process suitable for the material of the component 202 (i.e., the substrate region 204). For example, the region 320 can be removed by cutting, electrical discharge machining, grinding, etc. The surface 322 of the substrate region 204 is generally in a form such that the surface can have a porous region 200 that is easy to additively manufacture (i.e., print) thereon. In this regard, the surface 322 can be, for example, planar, so that the surface can be positioned in a powder bed in the AM system 210, and the porous region 200 (and possible replacement region 206) can be printed on the surface. In some embodiments, the surface 322 can also have a selected roughness for adhering the porous region 200 to the surface; however, this is not required in all cases.

[0074] In alternative embodiments, the area to be replaced 320 may not exist, and the teachings of the present disclosure are applied to the surface 322 of the substrate region 204 to add a new area to the surface (similar to the replacement area 206 described herein). For example, a new wear layer or area (not shown) may be added to the substrate region 204 without removing any previously existing area 320 of the substrate region.

[0075] like FIG. 8A to FIG. 8B As shown in , embodiments of the present disclosure may additively manufacture (i.e., form) a porous region 200 on a surface 322 of a dense base region 204 (possibly after removing the region to be replaced 320), and then the formed dense replacement region 206 is coupled to the porous region 200. Alternatively, as FIG. 9A to FIG. 9BAs shown in , embodiments of the present disclosure can additively manufacture (i.e., form) a porous region 200 on a surface 330 of a (formed) dense replacement region 206, and then couple the porous region 200 (having a replacement region 206 thereon) to a surface 322 of a dense base region 204. Thus, the porous region 200 can be additively manufactured on one of the surface 322 of a dense base region 204 (hereinafter referred to as “base region 204”) and the surface 330 of a dense replacement region 206 (hereinafter referred to as “replacement region 206”). More specifically, FIG. 8A to FIG. 8B The porous region 200 is shown additively manufactured on the surface 322 of the dense base region 204, while FIG. 9A to FIG. 9B The porous zone 200 is shown to be additively manufactured on the surface 330 of the replacement zone 206. In any case, the porosity of the porous zone 200 can be 2% to 50% of the open space volume of the porous zone: the total volume. In another embodiment, the porosity of the porous zone 200 can be 10% to 40% of the open space volume of the porous zone: the total volume. Alternatively, the porous zone 200 can have any porosity previously described herein. As will be further described herein, the porous zone 200 can have any number of sub-zones with different porosities.

[0076] More about FIG. 8B to FIG. 8E and FIG. 9B to FIG. 9F , alternative embodiments of the present disclosure may additively manufacture the porous region 200 wherein the first member 332 is configured to lockingly engage with the second member 334 of the replacement region 206 or the base region 204. Figure 8B In the embodiment, the additive manufacturing includes optionally forming the porous region 200, wherein the first member 332 is configured to be lockedly engaged with the second member 334 of the replacement region 206, such as FIG. 8C to FIG. 8E Here, the replacement area 206 is formed with or modified to include a second member 334. In contrast, in Fig. 9B In the embodiment, the additive manufacturing includes optionally forming the porous region 200, wherein the first member 332 is configured to be lockedly engaged with the second member 334 of the base region 204, such as FIG. 9C to FIG. 9F Here, the base region 204 is formed with or modified to include a second member 334, for example by adding the second member to the surface 322 of the base region 204 or machining the second member into the surface. FIG. 8B to FIG. 8E In, members 332, 334 include exemplary straight tongue and groove members, and in FIG. 9B to FIG. 9F , members 332, 334 include exemplary dovetail tongue and groove members. Any form of members 332, 334 that can align and / or limit movement between the porous region 200 and the replacement region 206 or the base region 204 can be used. Although one set of members 332, 334 is shown, more than one set can be used.

[0077] In certain embodiments, additive manufacturing may also include forming any type of improvement to the component 202 in the porous region 200, including, for example, structures that did not previously exist in the damaged portion that was removed. Fig.11A As shown in , additive manufacturing may optionally include forming cooling channels 336 in the porous region 200. The cooling channels 336 may extend in any manner in the porous region 200, such as in a serpentine path in the porous region or extending through the outer side surface of the porous region 200. Any advantageous internal structural changes may be made in the porous region 200.

[0078] refer to Figure 8C and FIG. 9C to FIG. 9D The method may further include positioning the replacement region 206 and the base region 204 together with the porous region 200 located between the replacement region and the base region. Figure 8C In the embodiment, since the porous region 200 is formed on the base region 204, the positioning can include positioning the replacement region 206 on the porous region 200, i.e., on the surface 352 of the porous region 200. This method is advantageous because any number and type of replacement regions 206 can be manufactured and used for repair work on the component 202. As an option, in the case of providing members 332, 334, such as Figure 8C As shown in , positioning may include lockingly engaging the porous region 200 and the replacement region 206 with the first member 332 and the second member 334. FIG. 9C to FIG. 9D In the embodiment, since the porous region 200 is formed on the replacement region 206, the positioning may include positioning the porous region 200 (with the replacement region 206 attached thereto) on the base region 204, i.e., the surface 352 of the porous region 200 is positioned on the surface 322 of the base region 204. As an option, in the case where members 332, 334 are provided, such as Fig. 9C As shown in , positioning can include lockingly engaging the porous zone 200 and the base zone 204 together with the first member 332 and the second member 334. Positioning can include any type of desired movement of the zones together, such as vertical and / or horizontal alignment, sliding engagement, etc. Any necessary techniques for temporarily holding the zones in place can be used, such as clamps, tape, etc.

[0079] Fig.8D and Fig.9E The porous region 200 is shown to be infiltrated with a brazing material 310 to join the base region 204, the replacement region 206, and the porous region 200 together. The brazing material 310 may include any brazing composition now known or later developed, such as, but not limited to: GE (Alstom) B1P, Amdry TMD15, DF4B or BRB, some of the formulations in these brazing compositions are listed in the following table together with other brazing material formulations:

[0080]

[0081] Infiltration can include any now known or later developed brazing process, such as using a vacuum brazing system, an induction brazing system, and / or an inert gas atmosphere heating system and related techniques. In a non-limiting example, brazing can include, for example, applying a brazing material and applying heat to liquefy the brazing material and cause the brazing material to flow into, through, and around the porous region 200 by capillary action.

[0082] The infiltration is based at least on the characteristics of the porosity of the porous zone 200 and the brazing material 310 is injected into the porous zone 200. As used herein, the infiltration that occurs "at least" in part based on the "characteristics" of the porosity indicates that the porosity can produce different infiltration characteristics, such as brazing material volume, pattern within the porosity, crystallization, chemical gradient and composition, and other characteristics. However, as understood in the art, other factors may also affect the infiltration characteristics, such as the type of brazing material and the characteristics of the brazing process, such as but not limited to: temperature, pressure, positioning of the component 202 and the porous zone 200. Different porosities within the sub-zones of the porous zone 200 with the same brazing material 310 may have at least one different physical property. In this way, the porosity can be customized to select those physical properties because the porosity may affect those physical properties. In one example, the porosity of a certain sub-region of the porous region 200 may be higher (i.e., less dense) than the porosity of other porous sub-regions of the porous region 200 and may include more brazing material 310 in the certain sub-region. In another example, the sub-regions of different porosities may be layers within the porous region 200 from its interior to the outer edge sub-region 340. Fig.11A In another example shown in FIG. 1 , different porosities may be used on different sides of the porous region 200, for example, sides 326 and 328 of the porous region 200 may have different porosities. In this way, the porous region 200 and different sides of the component 202 may have different physical properties. In the case of the airfoil 150, 176 of the nozzle 126 or the blade 132, as shown in FIG. Figure 3 and Figure 4As shown in , the pressure side outer wall 152, 178 of the airfoil can have different physical properties from the suction side outer wall 154, 180 of the airfoil, respectively. Any of the physical properties described herein can also be customized based on different porosities and / or different brazing materials. As noted, depending on the brazing material 310 used, different porosities can allow customization of the physical properties of the component 202, such as: joint adhesive bond strength, stress resistance / strain resistance, ductility, wear resistance, oxidation resistance, thermal conductivity, electrical conductivity, surface roughness, hardness and / or quality. In the presence of variable porosity, infiltration includes causing the brazing material 310 to travel through and infiltrate a varying porosity based on the properties of the brazing material 310 (e.g., a gradient of porosity, graded porosity, and other properties). In some examples, more brazing material 310 can produce stronger joint adhesive bond strength, higher ductility, higher thermal or electrical conductivity, or higher oxidation resistance, and less brazing material 310 can produce less surface roughness, less hardness, lower joint adhesive bond strength, lower ductility, lower thermal or electrical conductivity, or lower oxidation resistance. In any case, controlling the amount of brazing material and the porosity of the sub-regions of the porous zone 200 allows control of the physical properties of the final product. In addition, compared to conventional narrow gap filling brazing processes and due to the strict manufacturing tolerances required for narrow gap brazing, the multiple flow paths for the brazing material 310 using the porous zone 300 can reduce the possibility of lack of filling and / or voids along the brazed joint. Therefore, despite the use of the porous zone 200 in the component 202, the component can still be at least 98% solid.

[0083] In certain embodiments, different brazing materials 310 may be used in different portions of the porous region 200, thereby providing for further customization of the physical properties of the porous region 200 and the region of the component 202. Fig.11A , a first braze material 310A may be used on a first portion or side 326 of the component 202, and another braze material 310B different from the first braze material 310A may be used on a different portion or side 328 of the component 202. In one example, referring to Figure 3 , Figure 4 and Fig.11A, the first portion or side 326 of the component 202 may be the first (concave pressure) side outer wall 152, 178 of the airfoil 150, 176, and the second or side 328 of the component 202 may be the second (convex suction) side outer wall 154, 180 of the airfoil 150, 176. In addition to the different porosities of the sub-regions of the porous zone 200, the different braze materials 310A, 310B on the different portions or sides 326, 328 may also be tailored to the expected environment of the component 202 at those locations. As will be appreciated, the variations in braze materials and / or porous zones that may address different situations are enormous.

[0084] Fig. 8E and Fig.9F Also shown are exemplary optional finishing steps for component 202, such as, but not limited to, machining to smooth the outer surface and remove excess brazing material. As noted, the teachings of the present disclosure can eliminate the need for other finishing steps that are typically used to address residual stresses present in the material after additive manufacturing, such as shot peening, heat treatment, hot isostatic pressing (HIP), etc.

[0085] refer to FIG. 7A to FIG. 7B and FIG. 10A to FIG. 10E , another embodiment of the method according to the present disclosure will now be described. FIG. 7A to FIG. 7B , the method may include removing the region to be replaced 320 from the dense base region 204 of the component 202 to leave a surface 322 on the base region 204. The process may be as previously described herein.

[0086] FIG. 10A to FIG. 10C The additive manufacturing of the porous zone 200 on the surface 322 of the dense substrate zone 204 is shown, followed by the additive manufacturing of the dense replacement zone 206 on the porous zone 200. More specifically, the porous zone 200 is printed sequentially on the surface 322 of the substrate zone 204, followed by the printing of the replacement zone 206. While printing is in progress (i.e., in operation), the AM system 210 can be used to control the switching from printing a dense material for the substrate zone 204 or the replacement zone 206 and a porous material for the porous zone 200, and in particular, the operation of the melting beam sources 212, 214, 216, 218 can be used to control the switching. As noted, the porosity of the porous zone 200 can be 2% to 50% of the open space volume of the porous zone:total volume. Alternatively, the porous zone 200 can have any other porosity range described herein. Different porosities can be formed in the porous zone 200. As Fig. 10CAs shown in , additive manufacturing may include forming a higher porosity in at least one of the following: the first segment 390 of the porous zone 200 closest to the replacement zone 206 and the second segment 392 of the porous zone 200 closest to the base zone 204 than in the third segment 394 located between the first segment 390 and the second segment 392. That is, the segments 390 and / or 392 of the porous zone 200 that are closer to the replacement zone 206 and / or the base zone 204, respectively, are more porous than the central segment 394 of the porous zone 200. Other arrangements of different porosities are also possible. The porous zone 200 may also have any kind of internal structure, such as the cooling channel 336 ( Fig.11A ), as described herein.

[0087] Fig. 10D The porous region 200 is shown infiltrated with a brazing material 310 to secure the base region 204, the replacement region 206, and the porous region 200 together. The infiltration may include any brazing process described herein. Here, "secured" indicates a stronger connection between the regions than would be produced by additive manufacturing alone. In the case of having different porosities in different sections 390, 392, 394 of the porous region 200, as described with respect to Fig. 10C As described, more brazing material 310 penetrates into at least one of the first section 390 and the second section 392 compared to the third section 394 of the porous zone 200. In this way and depending on the brazing material 310, the portions of the joints 370, 372 between the porous zone 200 and the replacement zone 206 and between the porous zone 200 and the base zone 204 can have customized physical properties, such as stronger joint adhesive bond strength, oxidation resistance, stress resistance, respectively. As noted, different brazing materials 310 in different sections can also provide different physical properties.

[0088] Fig.10E Exemplary optional finishing steps for component 202 are shown, such as, but not limited to, machining to smooth the outer surface and remove excess braze material. As noted, the teachings of the present disclosure can eliminate the need for other finishing steps, such as shot peening, heat treatment, hot isostatic pressing (HIP), etc.

[0089] Further with respect to the porous region 200, in any of the embodiments described herein, the size of the porous region 200 may be selected by a user to form a joint 370 ( Fig. 8E , Fig.9F , Fig.10E ) or 372( Fig.10E). In most but not all cases, the porous region 200 has the horizontal shape and size of the surface 322 of the base region 204 or the surface 330 of the replacement region 206 on which the porous region is additively manufactured. The thickness T ( Figure 8C , Fig.9D , Fig. 10C ) can be selected to absorb as much brazing material 310 as necessary to form any desired physical properties for the joints 370, 372 between the replacement region 206 and the base region 204, such as better oxidation resistance or stress resistance. The thickness T can be increased by using the AM system 210 ( Figure 5 ) is controlled by the number of layers of the porous area 200 formed. The porous area 200 and the replacement area 206 together have a to-be-replaced area 320 ( FIG. 7A to FIG. 7B ) shape and size. In this way, once the replacement region 206 is coupled to the base region 204 using the porous region 200 and the brazing material 310, the final component 202 has the same shape and size as the initial component to be repaired 202X ( FIG. 7A to FIG. 7B ) of the same size.

[0090] Further regarding the porosity of the porous region 200, Fig.11A 200. The porosity of the porous region 200 can be tailored in many ways to direct the brazing material 310 ( FIG. 8D to FIG. 8E , FIG. 9E to FIG. 9F , FIG. 10D to FIG. 10E ) and form the desired physical properties of the porous zone 200 having the brazing material 310 infiltrated thereon. That is, the porosity of the porous zone 200 is controlled (i.e., customized) to control the flow of the brazing material in the porous zone during the brazing process that couples the base zone 204 and the replacement zone 206 with the porous zone 200. In this regard, the porosity of the porous zone 200 can be adjusted along the length L ( Fig.11A )、Width W( Fig.11A ) and thickness T( Figure 8C , Fig.9D , Fig. 10C ) changes. That is, the porous region 200 can have a variable porosity. The variable porosity change can be gradual, step-wise, or incremental. Subregions with different porosities can 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 connecting channels. Fig.11AAn example is shown in which an outer edge sub-region 340 of the porous region 200 has a higher porosity than one or more inner porous sub-regions 342 located inside the outer edge sub-region 340. In this way, more brazing material 310 can penetrate into the edge sub-region 340 where it meets the edge of the replacement region 206 and / or the base region 204 to form a stronger joint. In other embodiments, such as Fig. 11B As shown in the side view of FIG. 2 , a surface sub-region 344 or 346 of the porous region 200 that may contact the surface 322 of the base region 204 and / or the surface 330 of the replacement region 206 may have a higher porosity than one or more inner porous sub-regions 348 positioned inside the surface sub-regions 344, 346. In this way, more brazing material 310 may infiltrate the surface sub-regions 344, 346 where it meets the corresponding surface of the replacement region 206 and / or the base region 204 to form a stronger joint 370 ( Fig. 8E , Fig.9F , Fig.10E )、372( Fig.10E ). For example, Figure 8B As shown in FIG. 8A to FIG. 8E In an embodiment of the present invention, additive manufacturing may include forming a higher porosity in a location 350 at or near a surface 352 of the porous region 200 that contacts the replacement region 206 than in another location 354 of the porous region 200 that is closer to the surface 322 of the base region 204. Similarly, as Fig. 9B As shown in 9A to 9F In an embodiment of the present invention, additive manufacturing may include forming a higher porosity in a location 356 at or near the surface 352 of the porous region 200 that contacts the surface 322 of the base region 204 than in another location 360 in the porous region 200 that is closer to the surface 330 of the replacement region 206. In either case, during the infiltration step, more brazing material 310 infiltrates into the porous region 200 at the location with the higher porosity than at the location with the lower porosity. It will be appreciated that Figure 8B , Fig. 9B , Fig.11A and Fig. 11B The options shown in can be used together or separately. In other embodiments, only certain sections of the edge sub-region 340 and / or the surface sub-regions 344, 346 can have different porosities. Many options in terms of porosity within the porous region 200 are possible to provide the physical properties of the structure formed by the porous region 200 and the brazing material 310 to be infiltrated and formed.

[0091] Figure 3 , Figure 4 , Fig. 8E , Fig.9F and Fig.10EAn embodiment of a component 202 according to an embodiment is shown. The component 202 includes a dense substrate area 204, a dense replacement area 206, and an AM porous area 200 located between the substrate area 204 and the replacement area 206. As described herein, the substrate area 204 and the replacement area 206 can be dense materials and can be solid materials in one example, i.e., have a porosity of 0%. As noted, the porosity of the porous area 200 is 2% to 50% of the open space volume of the AM porous area: the total volume. The brazing material 310 infiltrates the porous area 200 at least based on the characteristics of the porosity, thereby making the porous area non-porous and connecting the substrate area 204, the porous area 200, and the replacement area 206 together. That is, the porous area 200 having the brazing material 310 forms a solid or nearly solid section, i.e., a dense section, that connects the substrate area 204 and the replacement area 206 together. As noted, the porosity of the porous region 200 may vary along at least one of the length, width, and thickness of the porous region between the base region 204 and the replacement region 206. It should also be noted that the base region 204 and the replacement region 206 need not have the same porosity or the same material. The porous region 200 may also include additional structures therein, such as cooling channels 336 ( Fig.11A ). Fig.11A As shown in , different brazing materials 310A, 310B may be used in different sub-regions of the porous region 200 to form different physical properties around or within the porous region 200. Although specific locations of different porosities of sub-regions in the porous region 200 have been shown herein, it should be emphasized that different porous sub-regions may be arranged in any manner to provide different brazing material infiltration characteristics and different physical properties to the component 202.

[0092] like Figure 1 to Figure 2 As shown in , embodiments of the present disclosure may also include a turbine 100 including a turbine assembly 110 and at least one component 202, as described herein. Component 202 may take the form of a turbine stationary nozzle 126, a turbine rotating blade 132, or other component of turbine 100. The porous region 200 may be used in a newly manufactured component or a repaired component.

[0093] The present disclosure provides various technical and commercial advantages, examples of which are discussed herein. For repair, the porous zone can provide a higher percentage of the base metal alloy (e.g., >60%) in certain areas, which can produce improved physical properties compared to, for example, pre-sintered preforms. The porous zone can also provide a weld / melt particle matrix (e.g., with a superalloy metal substrate) with a brazing material filler, which is stronger than conventional metal particles surrounded by the brazing material. Compared with conventional narrow gap filling brazing processes, the multiple flow paths for the brazing material using the porous zone can also reduce the possibility of lack of fillers and / or voids along the brazed joint. The porous zone can be formed to have a porosity difference to allow highly customized brazing material flow. Compared with a machined solid porous zone with a narrow gap for the brazing material, the porous zone also accommodates larger joint gap size changes. The repair using the teachings of the present disclosure is stronger than the traditional narrow gap brazing process, does not require specific post-repair finishing, and also provides improved physical properties compared to current technologies (such as pre-sintered preforms (PSP)). The porous regions reduce stress at the joints between dense regions and can be tailored to form physical properties that differ from those of the base and replacement regions alone. Additionally, additive manufacturing of metal coupons using porous regions (in addition to removing the need for post-processing such as shot peening, HIP, etc.) reduces or eliminates the potential for strain aging cracking, as opposed to direct printing of dense coupons.

[0094] As used throughout the specification and claims, approximate language can be used to modify any quantitative representation that can be permitted to vary without resulting in a change in the basic function to which it is associated. Therefore, values ​​modified by one or more terms (such as "about", "approximately" and "substantially") are not limited to the precise values ​​specified. In at least some cases, approximate language can correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range limitations can be combined and / or interchanged; unless the context or language indicates otherwise, these ranges are identified and include all subranges contained therein. "About" or "approximately" applied to a particular value of a range applies to both end values ​​and may indicate + / -10% of the value unless otherwise dependent on the precision of the instrument for measuring the value.

[0095] The corresponding structures, materials, actions and equivalents of all means or steps plus function elements in the following claims are intended to include any structure, material or action for performing functions in conjunction with other claimed elements specifically claimed. A description of the present disclosure has been given for the purpose of illustration and description, but it is not intended to be exhaustive or to limit the present disclosure to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and essence of the present disclosure. The embodiments are selected and described in order to best explain the principles and practical applications of the present disclosure, and to enable other persons of ordinary skill in the art to understand the various embodiments of the present disclosure and various modifications thereof suitable for the intended specific use.

Claims

1. A component (202), comprising: Dense first zone; Dense second zone; An additively manufactured (AM) porous zone (200), the additively manufactured (AM) porous zone being located between the dense first zone and the dense second zone, the porosity of the AM porous zone (200) being 2% to 50% of the open space volume of the AM porous zone (200): the total volume; and A brazing material (310) connects the dense first zone, the AM porous zone (200) and the dense second zone together, and the brazing material (310) infiltrates into the AM porous zone (200) at least based on the characteristics of the porosity.

2. The component (202) of claim 1, wherein the porosity of the AM porous zone (200) varies along at least one of a length, a width, and a thickness of the AM porous zone between the dense first zone and the dense second zone.

3. The component (202) according to claim 1, wherein the porosity is 10% to 40% of the open space volume of the AM porous zone (200):total volume.

4. The component (202) of claim 1, wherein the AM porous region (200) includes cooling channels (336) in the AM porous region.

5. The component (202) of claim 1, wherein the dense first region and the dense second region are solid materials.

6. A method for repairing a component (202), the method comprising: removing the region to be replaced (320) from the dense base region (204) of the component (202) to leave a first surface (322) on the dense base region (204); Additively manufacturing a porous region (200) on one of the first surface (322) of the dense base region (204) and the second surface (330) of the dense replacement region (206), wherein the porosity of the porous region (200) is 2% to 50% of the open space volume of the porous region (200): the total volume; positioning the dense replacement region (206) and the dense base region (204) together with the porous region (200) located between the dense replacement region and the dense base region; as well as A brazing material (310) is infiltrated into the porous region (200) to couple the dense base region (204), the dense replacement region (206), and the porous region (200) together.

7. The method of claim 6, wherein the additive manufacturing comprises forming the porous region (200) on the first surface (322) of the dense base region (204), and the positioning comprises positioning the dense replacement region (206) on the porous region (200).

8. A method according to claim 7, wherein the additive manufacturing includes forming a higher porosity in a first position at a third surface of the porous zone (200) contacting the dense replacement zone (206) or near the third surface than at a second position of the porous zone (200) closer to the first surface (322) of the dense base zone, and wherein the infiltration includes infiltrating more brazing material (310) into the porous zone (200) at the first position than at the second position.

9. A method according to claim 7, wherein the additive manufacturing includes forming the porous zone (200) having a first member (332), the first member being configured to be lockingly engaged with a second member (334) of the dense replacement zone (206), wherein the positioning includes lockingly engaging the porous zone (200) and the dense replacement zone (206) with the first member and the second member (332, 334).

10. The method of claim 6, wherein the additive manufacturing comprises forming the porous region (200) on the second surface of the dense replacement region (206), and the positioning comprises positioning the porous region (200) on the first surface of the dense base region (204).

11. A method according to claim 10, wherein the additive manufacturing includes forming a higher porosity in a first position at or near a third surface of the porous zone (200) contacting the first surface (322) of the dense base zone (204) than at a second position in the porous zone (200) closer to the second surface (330) of the dense replacement zone (206), wherein the infiltration includes infiltrating more brazing material (310) into the porous zone (200) at the first position than at the second position.

12. A method according to claim 10, wherein the additive manufacturing includes forming the porous zone (200) having a first member (332), the first member being configured to be lockedly engaged with a second member (334) of the dense base zone (204), wherein the positioning includes lockingly engaging the porous zone (200) and the dense base zone (204) with the first member and the second member (332, 334).

13. The method according to claim 6, wherein the porous area (200) and the dense replacement area (206) jointly have the shape and size of the area to be replaced (320).

14. The method of claim 6, wherein the porosity of the porous zone (200) varies along at least one of a length, a width, and a thickness of the porous zone between the dense replacement zone (206) and the dense base zone (320).

15. The method of claim 6, wherein the dense base region (320) and the dense replacement region (206) are solid materials.

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