Method for joining components at narrow and uniform brazed joints

Abstract

A method of joining a first component and a second component includes providing the first component including a first surface; providing a second component comprising a second surface; forming a brazed joint between the first surface and the second surface using a settling electrical discharge machining (EDM) apparatus wherein the first component functions as an electrode of the settling EDM apparatus and generates a voltage between the first component and the second component such that the brazed joint is formed by electrical discharge corrosion of at least one of the first component and the second component; and securely coupling the first component and the second component together along the brazed joint.

Description

Background Art

[0001] The field of the present disclosure relates generally to joining components at a brazed joint, and more particularly to a method of joining components that includes forming a narrow and uniform joint between surfaces of the components with a small gap tolerance. In one embodiment, the joint is formed using a sinker-type electro-discharge machining apparatus in which one of the components is used as an electrode that works against a surface of the other component to enable complementary surface profiles to be machined in the components.

[0002] For at least some known components that are made in whole or in part from metal alloys, cracks or defects may occur in the components during normal operation or use. For example, at least some known rotating machines use stainless steel and nickel-based, cobalt-based, and iron-based superalloys for components that are exposed to the heat flow path of the rotating machine during operation. The heat flow path may subject the components to thermal and / or mechanical loads, stresses, and strains, which over time may cause cracks or other defects to form in the components. When cracks or defects occur in such components, the damaged components are typically remedied by repairing the damaged area with a filler component made from a similar metal alloy material that is capable of withstanding the high temperatures, stresses, and / or strains from exposure to the heat flow path.

[0003] Some known methods of repairing such rotating machine components require removing the damaged area from the component (e.g., via machining), forming a cutout area in the component, and then inserting a filler insert or coupon that is connected (e.g., via brazing) to the component within the cutout area. For those components that are exposed to a heat flow path and are made of superalloys, brazing is a common technique for connecting the insert within the component. In a typical brazing process, a brazing material is applied within a gap or joint defined between the insert and the cutout area of ​​the component. The brazing material is then melted so that the liquid or molten brazing material can fill the joint via capillary action. The molten brazing material is then cooled as it solidifies, firmly connecting the insert within the component along the joint.

[0004] High-quality brazed connections between inserts and components help to mitigate or eliminate the tendency of inserts to detach from components in response to mechanical and thermal loads imposed on components during operation of rotating machines. A key factor in achieving high-quality brazed connections is a tight, well-fitting brazed joint formed between inserts and components. In fact, the narrow and uniform gap along the brazed joint promotes the capillary action of the molten brazing material to completely fill the joint and solidify with little or no porosity in the completed brazing. To this end, the surface profiles of the inserts and components defining the brazed joint must be substantially matched to enable the formation of a narrow gap with a tight gap tolerance. A higher degree of surface profile mismatch between the cutouts of the inserts and components forms a wider gap and / or a local wide gap zone along the brazed joint, which can limit the capillary action of the molten brazing material to completely fill the brazed joint, thereby resulting in a higher porosity in the solidified brazing material and a lower quality of the brazed connection.

[0005] Inserts and / or components are typically machined using milling or wire-cut electrical discharge machining (EDM) so that the surface profiles of the insert and component can be substantially matched and a brazed joint is formed. However, conventional machining techniques are limited and may often fail to achieve a narrow brazed joint with a desired gap tolerance. For example, heat flow path components typically have complex three-dimensional geometric surface profiles that are difficult to match using conventional machining such as milling and wire-cut EDM, in which components and inserts are machined independently. In addition, machining elements (i.e., rotary cutters and / or wire electrodes) may be limited in their ability to reach certain areas on the insert and / or component that require machining to obtain a desired surface profile. Therefore, a method for joining components (such as for repairing heat flow path components) with a filler insert is needed, which includes a practical, cost-effective method for forming a narrow and uniform brazed joint to promote higher quality brazing between components. Summary of the invention

[0006] In one aspect, a method of joining a first component and a second component is provided. The method includes providing a first component including a first surface; providing a second component including a second surface; forming a brazed joint between the first surface and the second surface using a sinker electrical discharge machining (EDM) device, wherein the first component is used as an electrode of the sinker EDM device and a voltage is generated between the first component and the second component so that the brazed joint is formed by spark erosion of at least one of the first component and the second component; and firmly coupling the first component and the second component together along the brazed joint.

[0007] In another aspect, a method of repairing a component for use in a turbine engine is provided. The turbine engine component includes a first surface. The method includes providing a filler component including a second surface; forming a brazed joint between the first surface and the second surface using a sinker electrical discharge machining (EDM) device, wherein one of the turbine engine component and the filler component is used as an electrode of the sinker EDM device and a voltage is generated between the turbine engine component and the filler component to form the brazed joint by spark erosion of at least one of the turbine engine component and the filler component; and firmly coupling the turbine engine component and the filler component together along the brazed joint.

[0008] In another aspect, a method of joining a first component and a second component is provided. The method includes machining at least one of the first component and the second component to form a first joint between a first surface of the first component and a second surface of the second component; after machining, forming a second joint between the first surface and the second surface, wherein the second joint has a smaller gap tolerance than the first joint, and wherein the second joint is formed by spark eroding complementary surface profiles in the first surface and the second surface using one of the first component and the second component as an electro-discharge machining (EDM) electrode; and securely coupling the first component and the second component together along the second joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] These and other features, aspects and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters refer to like parts throughout the several views, and in which:

[0010] Figure 1 is a schematic diagram of an exemplary rotating machine;

[0011] Figure 2 is exposed to Figure 1 A perspective view of a portion of a heat flow path of a rotating machine and an exemplary component that has been repaired or refurbished;

[0012] Figure 3 is a schematic diagram of an exemplary sinker type electrical discharge machining apparatus for forming a brazed joint between two parts;

[0013] Figures 4 to 6 An exemplary process sequence is shown in which a narrow and uniform brazed joint is formed between two components; and

[0014] Figure 7 is a flow chart of an exemplary method of joining two components.

[0015] The corresponding reference numerals used in all the drawings represent corresponding parts. Unless otherwise specified, the drawings provided herein are intended to illustrate the features of the embodiments of the present disclosure. It is believed that these features are applicable to a variety of systems including one or more embodiments of the present disclosure. Therefore, the drawings are not intended to include all conventional features required for practicing the embodiments disclosed herein known to those of ordinary skill in the art. DETAILED DESCRIPTION

[0016] The exemplary embodiments described herein relate to a method for joining two parts together by forming a brazing joint between parts using sinker type electrical discharge machining (EDM). Specifically, in an exemplary embodiment, the first of the parts is used as an electrode of a sinker type EDM device and inserted into the surface of the second of the parts, wherein the second part is used as a workpiece of the sinker type EDM device. The EDM device is used to form complementary surface profiles between the first part and the second part with high precision. Therefore, a narrow and tightly fitting brazing joint with a small gap tolerance is formed between the parts. These parts can then be firmly connected together along the brazing joint via a brazing process and / or via another suitable technology (such as but not limited to welding or welding). The narrow and tightly fitting brazing joint enables high-quality brazing to be formed between the parts, which can withstand high temperatures, stresses and strains, such as those that may be experienced in the heat flow path of a rotating machine such as a gas turbine engine. Therefore, the exemplary method described herein can be appropriately implemented to join the parts in the heat flow path area for a turbine engine together. For example, in some embodiments, the exemplary methods described herein may be implemented to repair or refurbish a worn area of ​​a hot flow path component (eg, a rotor blade or nozzle wheel of a gas turbine engine) with a filler component (eg, an insert or coupon).

[0017] Using a sinker EDM to form a brazed joint according to an exemplary embodiment can overcome several disadvantages of machining techniques (such as milling or wire cutting EDM) that are commonly used to form brazed joints. In at least some conventional techniques, components are independently machined to form a surface profile that defines a brazed joint. However, using a separate machining operation to form a surface profile in a component increases the tendency of mismatching between surface profiles. The possibility that the surface profile will mismatch may be exacerbated by the complex three-dimensional geometry of one or both of the components. The sinker EDM process described herein overcomes these disadvantages by machining the surface profile together in a single machining operation, wherein the complex and / or precise features of the surface profile of one of the components or the complement of the profile are simultaneously and directly formed into another component via the EDM process. In addition, compared with conventional machining techniques, sinker EDM forms a narrow gap with a smaller gap tolerance along the brazed joint in a more reliable and / or more cost-effective manner.

[0018] Another disadvantage associated with conventional machining techniques may be the limited reach of the tool element (e.g., the rotary cutter of a mill and / or the wire electrode of a wire EDM device) because the size and shape of the component may make it difficult to access all areas of the component that require machining. As a result, improper braze joints and low-quality brazes may be formed when conventional machining is performed, which may result in component failure or higher material costs if the components cannot be remedied, and / or may result in higher manufacturing costs and lower efficiency if the components must be arranged in multiple different orientations within the machining equipment during the machining operation. Sinking EDM overcomes these disadvantages because the EDM electrode eliminates the disadvantage of having to use conventional machining tools to machine complex workpieces.

[0019] When introducing the elements of the various embodiments disclosed herein, the articles "one", "a", "the" and "said" are intended to mean one or more elements present in the elements and include plural references unless the context clearly indicates otherwise. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, and the description includes instances where the event occurs and instances where the event does not occur. In addition, reference to "an embodiment" is not intended to be interpreted as excluding the existence of additional embodiments that also include the listed features. In addition, unless there is a clear statement to the contrary, the terms "including", "comprising" and "having" are intended to be inclusive and mean that there may be additional elements in addition to the listed elements.

[0020] Unless otherwise indicated, approximate language as used herein, such as "substantially," "substantially," "approximately," and "about" indicate that, as one of ordinary skill in the art will recognize, the term so modified may apply only to an approximate degree, rather than an absolute or perfect degree. Thus, a value modified by one or more terms, such as "about," "approximately," and "substantially," is not limited to the precise value specified. In at least some cases, the approximate language may correspond to the precision of an instrument used to measure the value.

[0021] Unless otherwise indicated, the terms "first," "second," and the like are used herein merely as labels and are not intended to impose order, position, or hierarchical requirements on the items to which these terms refer. Furthermore, for example, reference to a "second" item does not require or preclude the existence of, for example, a "first" or lower numbered item or a "third" or higher numbered item.

[0022] Now referring to the accompanying drawings, Figure 11 is a schematic diagram of an exemplary rotary machine 100. The rotary machine 100 may be a turbine, and more specifically a turbine engine. In an exemplary embodiment, the rotary machine 100 is a gas turbine engine. In alternative embodiments, the rotary machine 100 may be any other turbine engine and / or rotary machine, including but not limited to a steam turbine engine, a gas turbofan aircraft engine, other aircraft engines, a wind turbine, a compressor, and a pump. The rotary machine 100 is interchangeably referred to herein as a turbine engine 100, but the embodiments are not limited to turbine engines.

[0023] In an exemplary embodiment, turbine engine 100 includes an intake section 102, a compressor section 104 downstream of intake section 102, a combustor section 106 downstream of compressor section 104, a turbine section 108 downstream of combustor section 106, and an exhaust section 110 downstream of turbine section 108. Turbine section 108 is coupled to compressor section 104 via rotor shaft 112. As used herein, the term "coupled" is not limited to direct mechanical, thermal, electrical, and / or fluid communication connections between components, but may also include indirect mechanical, thermal, electrical, and / or fluid communication connections between multiple components. In an exemplary embodiment, combustor section 106 includes a plurality of combustors 114. Combustor section 106 is coupled to compressor section 104 such that each combustor 114 is in fluid communication with compressor section 104. Rotor shaft 112 is also coupled to a load 116, such as, but not limited to, a generator and / or a mechanical drive application. In the exemplary embodiment, each of compressor section 104 and turbine section 108 includes at least one rotor assembly 118 coupled to rotor shaft 112. Each rotor assembly 118 of turbine section 108 includes a plurality of circumferentially arranged, radially extending turbine blades 119.

[0024] In operation, the intake section 102 delivers air 120 toward the compressor section 104. The compressor section 104 compresses the inlet air 120 to a higher pressure and then discharges the compressed air 122 toward the combustor section 106. The compressed air 122 is delivered to the combustor section 106 where it is mixed with fuel and combusted to generate high temperature combustion gases 124. The combustion gases 124 are delivered downstream toward the turbine section 108 and impinge on turbine blades 119, converting thermal energy into mechanical rotational energy for driving the rotor assembly 118 to rotate about the longitudinal axis 126. In general, the combustor section 106 and the turbine section 108 are referred to as the hot flow path section 109 or the hot gas section 109 of the turbine engine 100. The exhaust gas 128 is then discharged into the ambient atmosphere through the exhaust section 110.

[0025] In some embodiments, during operation of the turbine engine 100, components 204 of the hot gas section 109, such as but not limited to the turbine blades 119, stator impellers (not shown), and / or shrouds (not shown), may be exposed to temperatures up to, for example, 1250 degrees Celsius, thereby forming thermal stresses in the components. In the turbine section 108, the components 204 are also subjected to mechanical stresses during operation, such as stresses from high-speed rotation and from exposure to high-speed hot gases from the combustor 106. Such extreme operating conditions may cause cracks to form in the components 204 of the hot gas section 109 due to creep and / or fatigue and other defects, requiring repair. The components 204 may also be referred to herein as hot gas components 204 or hot flow path components 204.

[0026] Figure 2 2 is a perspective view of an exemplary repaired or refurbished hot flow path component 200 in which a filler insert 202 (also referred to as a filler component or coupon) is inserted into a cutout 224 formed in a hot gas component 204 and thereby replaces the cutout. The cutout 224 may be formed in a wear zone or area of ​​the component 204 in which a crack or other defect has formed during use in the turbine engine 100. In the illustrated example, the hot gas component 204 is a turbine blade that may be used as a turbine blade 119 in the turbine engine 100. The hot gas component 204 may alternatively be referred to as a turbine blade 204. However, the repaired hot gas component 200 is not limited to repaired or refurbished turbine blades. For example, other hot gas components of a turbine engine (e.g., stator impellers, shrouds, etc.) may be repaired with a filler component according to the methods described herein.

[0027] Turbine blade 204 includes a root 206 that enables turbine blade 204 to be coupled to rotor shaft 112 ( Figure 1). The root 206 may include a dovetail (not shown) configured to be mounted in a corresponding dovetail slot (not shown) formed in a periphery of a rotor disk (not shown) extending from the rotor shaft 112. The root 206 may also include a shank (not shown) extending between the dovetail and a platform 208 that extends at the connection of the airfoil 210 and the root 206 and defines a portion of the inner boundary of the heat flow path through the turbine section 108. The airfoil 210 is an active component of the turbine blade 204 that intercepts the flow of the combustion gases 124 and causes the rotor shaft 112 to rotate. The airfoil 210 includes a concave pressure side sidewall 212 and a circumferentially or laterally opposed convex suction side sidewall 214 that extends axially between a leading edge 216 and an opposed trailing edge 218 of the airfoil 210. The sidewalls 212 and 214 also extend radially from the platform 208 to an outboard tip 220 of the airfoil 210 . The turbine blade 204 may include a tip shroud 222 at the tip 220 of the airfoil 210 .

[0028] The turbine blades 204 may be fabricated from any suitable material capable of withstanding the operating conditions within the hot gas section 109. For example, the turbine blades 204 may be fabricated from nickel-based, cobalt-based, iron-based, nickel-iron-based superalloys, and / or combinations thereof. Such "superalloys" may contain about 50% or more nickel, cobalt, iron, or nickel-iron by weight, plus alloying elements added to improve the mechanical and physical properties of these alloys. For example, in some embodiments, the turbine blades 204 may be fabricated from a nickel-based superalloy, such as René N4 TM 、René N5 TM , René 108 TM , and IN-738. René N4 TM 、René N5 TM , René 108 TM , and Including γ' strengthened nickel-based superalloys. In some embodiments, turbine blade 204 can be made of a cobalt-based superalloy such as FSX-414. Although certain alloys have been presented herein for turbine blade 204, it should be understood that these alloys are merely exemplary and are not intended to be limiting. The materials used can vary depending on the intended application of component 204.

[0029] Repaired or refurbished turbine blade 200 includes coupon 202 positioned in cutout 224 formed in turbine blade 204. Cutout 224 may be formed by removing a worn area of ​​turbine blade 204, such as an area on the turbine blade where cracks or defects have formed during use in turbine engine 100. Suitable techniques for forming cutout 224 include, but are not limited to, milling, hand grinding, and electrical discharge machining (EDM) techniques. In an exemplary embodiment, cutout 224 is formed along leading edge 216 of airfoil 210 and extends from leading edge 216 into sidewalls 212 and 214. Airfoil 210 may be particularly susceptible to cracks or defects in an area adjacent leading edge 216 that intersects the flow of combustion gases 124 within hot gas section 109 of turbine engine 100. However, the location of cutout 224 is provided by way of example only, and other areas of airfoil 210 or turbine blade 204 may be replaced by coupon 202. For example, the cutout 224 may be formed at any area of ​​the component 204 where cracks, wear, or other defects may occur and require repair or refurbishment using the coupon 202 due to rotational stresses, exposure to forces from fast-flowing combustion gases, and / or cyclic thermomechanical strains on the component 204. In alternative embodiments, the defect may have been formed by any other process, such as, for example, intentionally or unintentionally during a casting or machining process of the component 204.

[0030] The coupon 202 may be made of a material similar to the turbine blade 204, such as the superalloys described above. In some embodiments, the coupon 202 may be made of a different superalloy than the turbine blade 204. For example, the coupon 202 may be made of a material that is more resistant to heat and / or mechanical loads than the material used to make the turbine blade 204. In some embodiments, the coupon 202 may be made of a nickel-chromium-based superalloy, a chromium-based superalloy, a tungsten-based alloy, a chromium carbide material, or a combination thereof. For example, the coupon 202 may be made of a chromium-based superalloy available from Special Metals Corporation, Huntington, W.Va. Nickel-chromium super alloy materials (including Alloy 600, Alloy 617 and Alloy 625). The coupon 202 may additionally and / or alternatively be made of a cobalt-chromium alloy such as Deloro Wear Solutions GmbH, Koblenz, Germany. One of a series of cobalt-chromium alloys, including 6) Manufacturing.

[0031] like Figure 2 As shown, the coupon 202 is positioned within the cutout 224 formed in the airfoil 210 with a close tolerance. The coupon 202 can have any suitable shape and / or size that substantially matches the shape and / or size of the cutout 224. For example, the coupon 202 can be formed using casting, molding, powder metal manufacturing, additive manufacturing or 3D printing and / or computer machining (e.g., computer numerical control machining). In a particular embodiment, the coupon 202 can be additively manufactured as a single component having a shape and / or size that substantially matches the shape and / or size of the cutout 224. As used herein, the term "additively manufactured" or "additive manufacturing method" corresponds to, but is not limited to, various known 3D printing manufacturing methods, injection extrusion deposition, wire, granular material bonding, powder bed and inkjet 3D printing, lamination, and photopolymerization. Various technologies associated with various 3D printing methods include, but are not limited to (unless stated in the claims) fused deposition modeling (FDM), electron beam freeform fabrication (EBF), direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), selective heat sintering (SHS), selective laser sintering (SLS), plaster-based 3D printing (PP), laminated object manufacturing (LOM), stereolithography (SLA), and digital light processing (DLP). The shape (e.g., outer wall angle / shape), size (e.g., cutout size), and features (e.g., internal cooling structures) of the coupon 202 can be customized for the specific application of the hot gas component 204 and the area of ​​the hot gas component replaced by the coupon 202.

[0032] The coupon 202 is coupled within the cutout 224 using any suitable technique to join the turbine blade 204 and the coupon 202. In various embodiments, the coupon 202 is coupled to the cutout 224 of the airfoil 210 via welding or brazing, wherein a filler material (e.g., a filler metal alloy) is applied to a recessed surface 226 of the leading edge 210 defined by the cutout 224 and / or to a surface 228 of the coupon 202 to be coupled to the recessed surface 226. The surfaces 226 and 228 are joined together to form a joint 230 with the filler material therebetween. The filler material is heated and subsequently cured to securely secure the coupon 202 to the airfoil 210 along the joint 230.

[0033] In an exemplary embodiment, brazing is typically used to securely secure coupon 202 to airfoil 210 along joint 230. A suitable brazing process may be performed on coupon 202 and turbine blade 204 within a heated chamber (e.g., a vacuum furnace) that both supplies heat and induces a vacuum during the brazing process. For example, the heated chamber may provide a uniform temperature in the environment within the heated chamber while simultaneously creating a sufficient vacuum in the environment to remove at least some gases present in the environment, such as, for example, oxygen, nitrogen, carbon dioxide, water vapor, and / or methane.

[0034] The brazing process includes applying a brazing filler material to the recessed surface 226 and / or the surface 228 of the coupon 202 to be connected to the recessed surface 226. Suitable brazing filler materials include, for example, pure brazing filler alloys (e.g., DF-4B diffusion brazing alloys), or one or more of aluminum, silicon, copper, silver, germanium, gold, nickel, cobalt, and boron. In some embodiments, the brazing filler alloy is a multi-component eutectic with a relatively low melting point compared to the component 204 and the coupon 202. For example, the brazing filler alloy may have a melting temperature of less than about 1120°C, or between about 900°C and about 1100°C. The brazing filler material may be entirely or substantially composed of the brazing filler alloy, or may include other materials in addition to the brazing filler alloy, such as superalloy powder and / or a binder.

[0035] With a brazing filler material applied to one or both of the surfaces 226 and / or 228, the coupon 202 is positioned within the cutout 224 such that the brazing filler material is sandwiched between the coupon 202 and the airfoil 210 along a joint 230. The coupon 202 and the turbine blade 204 are positioned in a heating compartment, and the environment within the heating compartment is heated to a suitable brazing temperature. The brazing temperature may vary depending on the brazing filler material and the materials forming the coupon 202 and the component 204. Typically, the brazing temperature is below the melting temperature of the coupon 202 and the component 204, and is high enough to melt, or at least partially melt, the brazing filler material. The molten brazing filler material is applied by capillary action to a gap (e.g., molten brazing filler material) defined along the joint 230 (which may also be referred to as a brazed joint 230). Figure 6 228. The environment may be maintained at the brazing temperature for any suitable length of time to allow capillary action of the molten brazing filler material to occur. The temperature in the environment is then reduced to allow the molten brazing filler material to cool and solidify, thereby firmly securing the coupon 202 to the airfoil 210 along the joint 230 and producing a repaired or refurbished component 200.

[0036] A high quality brazed connection between the coupon 202 and the component 204 requires a narrow gap width (e.g., less than about 100 micrometers (μm)) along the brazed joint 230, and minimal variation in the gap width across the brazed joint 230. The variation in the gap width across the brazed joint 230 may be referred to herein as the gap tolerance of the brazed joint 230. When the gap width and / or the gap tolerance increases, the capillary action of the molten brazing filler material is limited, and the molten brazing filler material may not completely fill the gap along the brazed joint 230. Therefore, when the brazing filler material cools and solidifies, pores or voids may be formed therein, which may reduce the quality of the brazed connection and increase the tendency of the coupon 202 to detach from the component 204 when used in the rotating machine 100. The gap width along the brazed joint 230 and the corresponding gap tolerance may depend on the level of matching between the surface profiles of the recessed surface 226 and the surface 228 of the coupon 202. The surface profiles (including topography and other three-dimensional features) of surfaces 226 and 228 must complement each other with high precision to achieve the narrow gap width and small gap tolerance of the braze joint 230, and thereby promote the capillary action of the molten braze filler material to substantially completely fill the gap along the braze joint 230.

[0037] According to an exemplary embodiment, the coupon 202 and the component 204 are subjected to a sinker type electrical discharge machining (EDM) operation to form a brazed joint 230 having a narrow gap width and a small gap tolerance. Sinker type EDM (also known as insert type EDM or punch type EDM) is conducive to accurately machining features into a component or workpiece. Complex three-dimensional features, small precision features, and close tolerance features in a workpiece are examples of features that are appropriately implemented by sinker type EDM. The sinker type EDM process may include an electrode having a "positive" profile or shape, which is "sunk" (inserted or burned) into the surface of the workpiece. The electrode works against the workpiece by spark erosion achieved by a voltage generated between the electrode and the workpiece, thereby removing material from the workpiece to produce a "negative" profile or shape in a machined surface that is substantially complementary or matched to the positive profile of the electrode, including complex, small and / or close tolerance features with high precision. With sinker type EDM, no pressure is applied to the material machined by the electrode because the features are burned into their shape, rather than being ground. Thus, very complex, highly precise shapes and / or patterns may be machined into a workpiece using a sinker EDM process that are virtually impossible to reproduce by other machining techniques such as, for example, milling or wire EDM.

[0038] Figure 3is a schematic diagram of an exemplary sinker EDM apparatus 300 that can be used to form a narrow and uniform braze joint between surfaces of two parts 302 and 304 to be joined together by brazing. In some embodiments, parts 302 and 304 can be Figure 2 , wherein the first component 302 is one of the coupon 202 and the component 204, and the second component 304 is the other 202 or 204. The sinker EDM apparatus 300 may be used to form a brazed joint 230 having a narrow gap width and a small gap tolerance between the coupon 202 and the airfoil 210.

[0039] In an exemplary embodiment, the sinker EDM apparatus 300 includes a controller 306 and an actuator 308 communicatively coupled to the controller 306. Any suitable actuator may be used as the actuator 308, such as a rotary actuator, a linear actuator, a pneumatic actuator, a hydraulic actuator, an electric actuator, etc. The actuator 308 is coupled to a punch 310. The punch 310 is coupled to the first component 302 directly or through a mechanical linkage such as a handle or an arm. In an exemplary embodiment, the first component 302 is used as an electrode of the sinker EDM apparatus 300, and the second component 304 is positioned on a work platform 312. In other embodiments, either the first component 302 or the second component 304 may be used as an electrode of the sinker EDM apparatus 300. The actuator 308 is operable to move the punch 310 and the electrode (e.g., the first component 302) toward the workpiece (e.g., the second component 304) during the sinker EDM process.

[0040] The power source 314 is operable to provide current to the first component 302 and the second component 304 so that a voltage is generated between the first component 302 and the second component 304. Suitably, the components 302 and 304 are each made of a conductive material (such as a metal or a metal alloy) so that current can be provided to the components 302 and 304 and a voltage can be generated between them. In one of the components 302 and 304, the sample block 202 ( Figure 2 ) and the other of the components 302 and 304 is the hot gas component 204 ( Figure 2), components 302 and 304 may be made of any of the above-mentioned superalloys or any combination of superalloys. The polarity of the voltage or the direction of the current between the first component 302 and the second component 304 depends on the type of charge supplied to the first component 302 and the second component 304. The polarity of the voltage may be positive or negative. A positive polarity is generated by providing a positive charge to the electrode or the first component 302 and a negative charge to the second component 304 through the power supply 314. A negative polarity is generated by providing a negative charge to the electrode or the first component 302 and a positive charge to the second component 304 through the power supply 314. The polarity may be static or unchanged during the sedimentation EDM process, or may be changed during the sedimentation EDM process (e.g., from positive polarity to negative polarity). The polarity may be selected or controlled according to the operating conditions and desired effects of the sedimentation EDM process, including but not limited to the type of material of the components 302 and 304, the desired accuracy, the desired duration of the sedimentation EDM process, etc.

[0041] The second component 304 and the work platform 312 can be positioned in a dielectric fluid box or chamber 316, and a dielectric fluid supplier 318 is connected to the chamber 316 fluid communication. For example, a dielectric fluid pump (not shown) can be used to provide the flow of dielectric fluid from the dielectric fluid supplier 318 to the chamber 316. The dielectric fluid can also circulate between the dielectric fluid supplier 318 and the chamber 316. The dielectric fluid supplier 318 may include a filter (not shown) and / or a cooling device (not shown) for processing the dielectric fluid circulating between the dielectric fluid supplier 318 and the chamber 316. As further described below, the dielectric fluid promotes the generation of high-intensity sparks between the surface 320 of the component 302 and the surface 322 of the component 304 under the sufficient voltage generated by the charge provided to the components 302 and 304. The high-intensity spark works on one or both of the surfaces 320 and 322 to achieve the complementary surface profiles in the surfaces 320 and 322 with high precision.

[0042] In an exemplary embodiment, the sinker EDM device 300 includes a controller 306 that is communicatively connected to an actuator 308, a power supply 314, and a dielectric fluid supplier 318. The controller 306 can communicate with one or more of these components via a communication interface that is communicatively connected to one or more of these devices. The communication interface may include, but is not limited to, a wired network adapter, a wireless network adapter, a mobile telecommunications adapter, a serial communication adapter, or a parallel communication adapter. The communication interface can receive a data signal from one or more remote devices (such as an actuator 308, a power supply 314, and / or a dielectric fluid supplier 318) or transmit a data signal to it.

[0043] The controller 306 is operable to control remote devices (e.g., actuators 308, power supplies 314, and / or dielectric fluid suppliers 318) of the sinker EDM device 300 by executing instructions stored in a memory device 328 via a processor 326, which is communicatively connected to the processor 326. The processor 326 may include one or more processing units, such as, for example, a multi-core configuration. The memory device 328 is one or more devices that allow storage and retrieval of information such as executable instructions or other data. The memory device 328 may include one or more computer-readable media, such as and not limited to random access memory (RAM), dynamic RAM, static RAM, solid state disk, hard disk, read-only memory (ROM), erasable programmable ROM, electrically erasable programmable ROM, or non-volatile RAM memory. The above memory types are exemplary only and are therefore not limited to the types of memory that can be used to store computer programs.

[0044] The processor 326 can be programmed by encoding the operation as one or more executable instructions and providing the executable instructions in the memory device 328. In various embodiments, the processor 326 can be programmed to control the operating conditions of the sinker EDM process based on the desired duration and efficiency of the sinker EDM process and the precision level and finish of the machined parts 302 and 304. For example, the processor 326 can adjust the power settings of the power supply 314, including, for example, the intensity of the current provided by the power supply 314 to the parts 302 and 304 and the polarity of the voltage generated between the parts 302 and 304. The memory device 328 can store data associated with the sinker EDM process, including but not limited to real-time and historical operating parameter values ​​or any other type of data. The memory device 328 can store instructions that can be executed by the processor 326 to control the sinker EDM process based on, for example, the type of material used for the parts 302 and 304, the required features to be machined in one or both of the surfaces 320 and 322, etc. In some embodiments, the processor 326 removes or "clears" data in the memory device 328 based on the age of the data. For example, the processor 326 may overwrite previously recorded and stored data associated with a subsequent time or event. In addition, or alternatively, the processor 326 may remove data that exceeds a predetermined time interval. In addition, the memory device 328 includes, but is not limited to, sufficient data, algorithms, and commands to enable the processor 326 to control the sedimentation EDM process for causing the sedimentation EDM device 300 to function as described herein.

[0045] In some embodiments, the controller 306 includes a display interface 330 coupled to the processor 326. The display interface 330 presents information, such as a user interface, to an operator of the submersible EDM device 300. In one embodiment, the display interface 330 includes a display adapter (not shown) coupled to a display device (not shown), such as a cathode ray tube (CRT), a liquid crystal display (LCD), an organic LED (OLED) display, or an "electronic ink" display. In some embodiments, the display interface 330 includes one or more display devices. In addition, or alternatively, the display interface 330 includes an audio output device (not shown), such as, but not limited to, an audio adapter, a speaker, or a printer (not shown).

[0046] In some embodiments, the controller 306 includes a user input interface 332. In an exemplary embodiment, the user input interface 332 is coupled to the processor 326 and receives input from an operator. The user input interface 332 may include, for example and without limitation, a keyboard, a pointing device, a mouse, a stylus, a touch-sensitive control pad (such as, but not limited to, a touch pad or a touch screen), and / or an audio input interface (such as, but not limited to, a microphone). A single component, such as a touch screen, may serve as both a display device for the presentation interface 330 and a user input interface 332.

[0047] In the operation of the sinker EDM device 300, the first component 302 is coupled to the punch 310, and the second component 304 is positioned on the work platform 312 in the chamber 316. The dielectric fluid is supplied to the chamber 316 from the dielectric fluid supplier 318. The actuator 308 moves the punch 310 and the first component 302 toward the second component 304 positioned on the work platform 312, so that the first component 302 and the second component 304 are at least partially immersed in the dielectric fluid in the chamber 316. A small gap can exist between the surfaces 320 and 322 (respectively) of the components 302 and 304, and the dielectric fluid fills the gap. Electric current is provided to each component 302 and 304 via the power supply 314. The dielectric fluid acts as an insulator so that electric current and opposite charges can be established in the components 302 and 304. When enough voltage is generated between parts 302 and 304, the insulating properties of the dielectric fluid are destroyed, so that electric current can flow between parts 302 and 304, which forms a high temperature zone between surfaces 320 and 322. The dielectric fluid in the high temperature zone is ionized, and a high-intensity electric spark is formed between surfaces 320 and 322. The spark melts and evaporates the material from surface 320 and / or surface 322. The direction of the current and the spark depends on the polarity, which in turn determines which of the surfaces 320 and 322 has experienced greater material removal. The sedimentation EDM process can be circulated so that a cold dielectric fluid can replace the heated dielectric fluid, which can be circulated back to the dielectric fluid supplier 318. The dielectric fluid circulated back to the dielectric fluid supplier 318 is optionally cooled to reduce the temperature of the dielectric fluid and restore its insulating properties, and / or is filtered to remove the material entrained in the dielectric fluid removed from the surface 320 and / or 322.

[0048] like Figure 3 As shown, in an exemplary embodiment, the surface 320 of the first component 302 has a surface profile including a three-dimensional feature (e.g., a surface topography). The surface 322 of the second component 304, which may be substantially flat or may have a surface profile that is not complementary to the surface profile of the surface 320, may be machined by a sinker EDM process to form a surface profile that is substantially complementary to the surface profile of the surface 320, with high precision relative to the topography of the surface 320, and to enable a brazed joint (e.g., Figure 6 A narrow and uniform gap is defined at the brazed joint 334 shown in FIG. Figure 6). In particular, in one embodiment, the voltage generated between the first component 302 and the second component 304 can have a positive polarity so that material removal by spark erosion occurs substantially along the surface 322 of the second component 304 to form a surface profile substantially complementary to the surface profile of the surface 320 of the first component 302. Alternatively, the surface 320 of the first component 302 can be machined into a surface profile substantially complementary to the surface profile of the surface 322 of the second component 304, which surface profile may include three-dimensional features (e.g., surface contours). In particular, in some embodiments, the voltage generated between the first component 302 and the second component 304 can have a negative polarity so that material removal by spark erosion occurs substantially along the surface 320 of the first component 302 to form a surface profile substantially complementary to the surface profile of the surface 322 of the second component 304, so that a brazed joint (e.g., Figure 6 A narrow and uniform gap is defined at the brazed joint 334 shown in FIG. Figure 6 In other embodiments, the polarity of the voltage between the first component 302 and the second component 304 can be cycled between positive and negative to remove material from both surfaces 320 and 322 and enable a brazed joint (e.g., Figure 6 A narrow and uniform gap is defined at the brazed joint 334 shown in FIG. Figure 6 The gap G2 shown in FIG.

[0049] During the sinker EDM process, controller 306 may determine the type of material from which components 302 and 304 are made, the type of braze joint between surfaces 320 and 322 (e.g., Figure 6 334) of the brazed joint shown in the figure, the desired duration of the sinker EDM process, and / or other factors to selectively change various operating conditions. For example, the controller 306 can (for example) use programmed instructions stored in the memory device 328 and executed by the processor 326 to control the polarity during the sinker EDM process. In addition and / or alternatively, the operator can use the user input interface 332 to selectively adjust the polarity during the sinker EDM process. Other operating conditions (e.g., duration, current intensity, and other conditions) can be controlled by the controller 306 based on programmed instructions stored in the memory device 328 and / or based on operator input at the user input interface 332.

[0050] Figures 4 to 6 An exemplary process sequence is shown in which a narrow and uniform brazed joint 334 is formed between the surface 320 of the first component 302 and the surface 322 of the second component 304. Figure 6). Components 302 and 304 may each be a sample block 202 and / or a heat flow path component 204 ( Figure 2 ), and the solder joint 334 may represent the solder joint 230 defined between the coupon 202 and the heat flow path component 204. Figure 7 describe Figures 4 to 6 The process sequence is Figure 7 is a flow chart of an exemplary method 400 of joining the first component 302 and the second component 304 .

[0051] In the exemplary embodiment, method 400 includes providing 402 a first component 302 having a first surface 320 and providing 404 a second component 304 having a second surface 322. Figure 4 As shown, first surface 320 and second surface 322 are initially non-complementary in their respective surface profiles, such that surfaces 320 and 322 are not suitable for joining (e.g., by brazing) at this stage of manufacturing. Additionally, at this stage, method 400 optionally includes machining 406 at least one of first surface 320 and second surface 322 to form first joint 336 ( Figure 5 ), also referred to as an intermediate joint or a rough joint. Machining 406 may use conventional machining techniques (e.g., milling, hand grinding, or wire EDM), in which surfaces 320 and 322 are independently machined to form a first joint 336. At this stage, a gap width G1 is defined along the first joint 336. In addition, at this stage, the first joint 336 may not generally be suitable for coupling (e.g., brazing) the first component 302 to the second component 304. For example, the gap width G1 may not be within a suitable gap width threshold (e.g., less than about 100 microns (μm)), and / or the variation in the gap width G1 may vary and may exceed the desired gap tolerance. Typically, conventional machining techniques in which surfaces 320 and 322 are independently machined can only practically achieve a gap tolerance as low as + / -30 μm, however, smaller gap tolerances are desired (e.g., within + / -10 μm, or within + / -5 μm). The relatively large gap width G1 and / or the relatively high gap tolerance along the first joint 336 may result in limited capillary action of the molten brazing filler material, which inhibits the molten brazing filler material from substantially filling the gap between the surfaces 320 and 322 along the first joint 336. Therefore, when the first component 302 and the second component 304 are coupled along the first joint 336, an undesirable connection between the first component 302 and the second component 304 will generally result in this situation.

[0052] Thus, the method 400 includes forming 408 a desired brazed joint 334 ( Figure 6), which is also referred to as the second joint. The brazed joint 334 is made of, for example, Figure 3 The sinker EDM device 300 shown is formed. The first part 302 or the second part 304 is used as an electrode of the sinker EDM device, and a voltage is generated between the first part 302 and the second part 304 by supplying current to each of the first part 302 and the second part 304. The generated voltage is sufficient to form a high-intensity spark between the first surface 320 and the second surface 322. The high-intensity spark acts on at least one of the first surface 320 and the second surface 322 to form a complementary surface profile in the parts 302 and / or 304, thereby forming a narrow and uniform gap along the brazed joint 334. The polarity of the voltage can be positive, where spark erosion occurs substantially at the second surface 322, and / or the polarity of the voltage can be negative, where spark erosion occurs substantially at the first surface 320. In some embodiments, the polarity of the voltage can alternate or cycle between positive and negative, so that spark erosion occurs at both the first surface 320 and the second surface 322 to form a complementary surface profile.

[0053] The brazed joint 334 formed 408 by spark erosion using a sinker EDM device has a gap width G2, characterized by a gap tolerance that is less than the gap tolerance of the gap width G1 of the first joint 336. For example, the gap tolerance of the brazed joint 334 can be within + / -10 μm, or within + / -5 μm. The gap width G2 is also appropriately within the desired gap width threshold, such as less than 100 μm. Therefore, the brazed joint 334 has a suitable gap width G2 and gap tolerance, which enables a high-quality connection (e.g., a high-quality braze) to be achieved between the first component 302 and the second component 304.

[0054] The method 400 also includes coupling 410 the first component 302 and the second component 304 along the brazed joint 334. In an exemplary embodiment, the first component 302 and the second component 304 are coupled 410 along the brazed joint 334 by securely fixing the first component 302 and the second component 304 via a brazing process along the brazed joint 334. Brazing may be performed as described herein by applying a brazing filler material to at least one of the first surface 320 and the second surface 322 after a sinker EDM process and producing molten brazing filler material along the brazed joint 334. The narrow gap width G2 and small gap tolerance of the brazed joint 334 facilitate sufficient capillary action of the molten brazing filler material, thereby enabling the molten brazing material to substantially fill the entire gap G2 between the surfaces 320 and 322 along the brazed joint 334. When the brazing filler material is cured, high quality brazed joint surfaces 320 and 322 with few or no voids or pores help limit or prevent the tendency of the first component 302 and the second component 304 to separate from each other when the joined components are used. For example, the joined components 302 and 304 can each be one of the coupons 202 or the heat flow path components 204 that are joined together to form a repaired or refurbished heat flow path component 200 ( Figure 2 ), which may be used in the hot flow path portion 109 of the turbine engine 100 ( Figure 1 A high quality braze along braze joint 230 / 334 couples coupon 202 and heat flow path component 204 together in a manner that may facilitate limiting or preventing a tendency for coupon 202 to become detached from repaired heat flow path component 200 during operation of turbine engine 100 .

[0055] The above-described systems and methods facilitate forming a narrow and uniform braze joint between two components, which enables a high-quality braze to be formed between the components with fewer or no defects formed in the braze, thereby reducing the tendency of the joined components to separate from each other along the braze joint and increasing the life of the connection between the components. An exemplary embodiment includes forming a braze joint between two components by sinker EDM, wherein one of the components is used as a sinker EDM electrode to form complementary surface profiles in the components to be joined by spark erosion of one or both surfaces. The complementary surface profiles formed by the sinker EDM process define a braze joint with a narrow gap width and a small gap tolerance, which facilitates excellent capillary action of the molten braze filler material along the braze joint and reliable brazing when the molten braze material solidifies. These systems and methods may be particularly advantageous for components used in extremely hot and high mechanical stress environments, such as components subjected to high temperatures and rotational stresses in the hot gas section of a gas turbine.

[0056] In addition, exemplary technical effects of the systems and methods described herein include at least one of: (a) reducing defects within brazed joints due to limited capillary action of the brazing filler material; (b) reducing the amount of brazing material required to supply the brazed joint when a braze is formed in the components; and (c) extending the life of the brazed connection between the components.

[0057] Other aspects of the disclosure are provided by the subject matter of the following clauses:

[0058] Item 1. A method for joining a first component and a second component, the method comprising: providing a first component including a first surface; providing the second component including a second surface; forming a brazed joint between the first surface and the second surface using a sinker electrical discharge machining (EDM) device, wherein the first component is used as an electrode of the sinker EDM device and a voltage is generated between the first component and the second component so that the brazed joint is formed by spark erosion of at least one of the first component and the second component; and firmly connecting the first component and the second component together along the brazed joint.

[0059] Clause 2. The method of clause 1, wherein the first component and the second component are fixedly coupled together to form a repair component for use within a heat flow path defined within a turbine engine.

[0060] Clause 3. The method of any of the preceding clauses, wherein providing the first component comprises providing the first component fabricated from a superalloy comprising at least one of nickel, iron, and cobalt.

[0061] Clause 4. The method of any of the preceding clauses, wherein providing the first component comprises providing the first component comprising a wear area defining the first surface and providing the second component for repairing the wear area.

[0062] Clause 5. The method of any of the preceding clauses, wherein forming the braze joint comprises defining a gap along the braze joint between the first surface and the second surface, the gap having a gap tolerance within + / - 5 microns.

[0063] Clause 6. The method of any of the preceding clauses, wherein a rough joint is defined between the first surface and the second surface prior to forming the brazed joint, wherein a gap tolerance of the brazed joint is less than a gap tolerance of the rough joint.

[0064] Clause 7. The method of any of the preceding clauses, further comprising machining at least one of the first surface and the second surface to form the rough joint prior to forming the brazed joint.

[0065] Clause 8. The method of any of the preceding clauses, wherein fixedly coupling the first component and the second component together further comprises fixedly securing the first component and the second component together via brazing along the brazed joint.

[0066] Clause 9. A method for repairing a component for use in a turbine engine, the turbine engine component including a first surface, the method comprising: providing a filler component including a second surface; forming a brazed joint between the first surface and the second surface using a sinker electrical discharge machining (EDM) device, wherein one of the turbine engine component and the filler component is used as an electrode of the sinker EDM device and a voltage is generated between the turbine engine component and the filler component to form the brazed joint by spark erosion of at least one of the turbine engine component and the filler component; and securely coupling the turbine engine component and the filler component together along the brazed joint.

[0067] Clause 10. The method of any preceding clause, further comprising machining a wear zone of the turbine engine component to define the first surface.

[0068] Clause 11. The method according to any of the preceding clauses, wherein the filler member is used as the electrode of the sedimentation EDM device.

[0069] Clause 12. The method according to any of the preceding clauses, wherein the turbine engine component is used as the electrode of the sedimentation EDM apparatus.

[0070] Clause 13. The method of any of the preceding clauses, wherein forming the braze joint comprises defining a gap along the braze joint between the first surface and the second surface, the gap having a gap tolerance within + / - 5 microns.

[0071] Clause 14. The method of any of the preceding clauses, wherein a rough joint is defined between the first surface and the second surface prior to forming the brazed joint, wherein a gap tolerance of the brazed joint is less than a gap tolerance of the rough joint.

[0072] Clause 15. The method of any of the preceding clauses, further comprising machining at least one of the first surface and the second surface to form the rough joint prior to forming the brazed joint.

[0073] Clause 16. The method of any of the preceding clauses, wherein fixedly coupling the turbine engine component and the filler component together further comprises fixedly securing the turbine engine component and the filler component together via brazing along the brazed joint.

[0074] Item 17. A method of joining a first component and a second component, the method comprising: machining at least one of the first component and the second component to form a first joint between a first surface of the first component and a second surface of the second component; forming a second joint between the first surface and the second surface after machining, wherein the second joint has a smaller gap tolerance than the first joint, and wherein the second joint is formed by using one of the first component and the second component as an electro-discharge machining (EDM) electrode to electro-spark erode complementary surface profiles in the first surface and the second surface; and securely connecting the first component and the second component together along the second joint.

[0075] Clause 18. The method of any of the preceding clauses, wherein the spark eroding comprises generating a voltage having a positive polarity between the EDM electrode and the other of the first component and the second component.

[0076] Clause 19. The method of any of the preceding clauses, wherein the spark eroding comprises generating a voltage having a negative polarity between the EDM electrode and the other of the first component and the second component.

[0077] Clause 20. The method of any of the preceding clauses, wherein fixedly coupling the first component and the second component together comprises fixedly coupling the first component and the second component via brazing along the second joint.

[0078] Exemplary embodiments of systems and methods for joining components at narrow and uniform brazing joints are described in detail above. The systems and methods are not limited to the specific embodiments described herein, but the components of the system and / or the steps of the method can be used independently and separately from other components and / or steps described herein. For example, these systems and methods can also be used in conjunction with many types of components, and are not limited to practicing only with components of rotating machines (e.g., gas turbine engines) as described herein. On the contrary, exemplary embodiments can be implemented and utilized in conjunction with many other brazing applications or applications involving joining components at joints defined by highly complementary surface features of components.

[0079] Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in others, this is for convenience only. Reference to "one embodiment" in the above description does not exclude the existence of additional embodiments that also include the described features. In accordance with the principles of the embodiments of the present disclosure, any feature of a drawing may be referenced and / or claimed in conjunction with any feature of any other drawing.

[0080] This written description uses examples to disclose embodiments of the present disclosure, including the best mode, and also enables any person skilled in the art to practice the embodiments of the present disclosure, including making and using any device or system and performing any combined method. The patentable scope of the embodiments described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A method of joining a first component and a second component, the method comprising: providing the first component including a first surface; providing the second component including a second surface; forming a brazed joint between the first surface and the second surface using a sinker electrical discharge machining (EDM) device, wherein the first component serves as an electrode of the sinker EDM device and a voltage is generated between the first component and the second component such that the brazed joint is formed by spark erosion of at least one of the first component and the second component; as well as The first component and the second component are securely coupled together along the brazed joint. 2 . The method of claim 1 , wherein the first component and the second component are fixedly coupled together to form a repair component for use within a heat flow path defined within a turbine engine.

3. The method of claim 1 or claim 2, wherein providing the first component comprises providing the first component fabricated from a superalloy comprising at least one of nickel, iron, and cobalt.

4. The method of any one of the preceding claims, wherein providing the first component comprises providing the first component comprising a wear zone defining the first surface and providing the second component for repairing the wear zone.

5. The method of any one of the preceding claims, wherein forming the brazed joint comprises defining a gap along the brazed joint between the first surface and the second surface, the gap having a gap tolerance within + / - 5 microns.

6. The method of any one of the preceding claims, wherein a rough joint is defined between the first surface and the second surface prior to forming the brazed joint, wherein a gap tolerance of the brazed joint is less than a gap tolerance of the rough joint.

7. The method of any one of the preceding claims, further comprising machining at least one of the first surface and the second surface to form the rough joint prior to forming the brazed joint.

8. The method of any one of the preceding claims, wherein fixedly coupling the first component and the second component together further comprises fixedly securing the first component and the second component together via brazing along the brazed joint.

9. The method of any one of the preceding claims, wherein providing the first component comprises providing a turbine engine component, and wherein providing the second component comprises providing a filler component.

10. The method of any one of claims 1 to 8, wherein providing the second component comprises providing a turbine engine component, and wherein providing the first component comprises providing a filler component.

11. A method according to claim 9 or claim 10, further comprising machining a wear zone of the turbine engine component to define the first surface.

12. The method according to any one of claims 9 to 11, wherein the filling member is used as the electrode of the sedimentation EDM apparatus.

13. The method according to any one of claims 9 to 12, wherein the turbine engine component is used as the electrode of the sedimentation EDM apparatus.

14. The method according to any one of the preceding claims, wherein the voltage generated between the first component and the second component has a positive polarity.

15. A method according to any one of the preceding claims, wherein the voltage generated between the first component and the second component has a negative polarity.

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