Braze joints for a component and methods of forming the same

A system for creating a braze joint within a component. The system includes an environment operable to reach a braze temperature sufficient to melt at least a portion of a braze material. The system also includes a component within the environment, the component including a base having a base surface, a recess depending from the base surface into the base to an inner edge, and a braze material within the recess and forming a cap above the base surface. The braze material fills the recess from the cap to the inner edge. The cap has an exposed braze surface. The system also includes an insulation layer that at least partially covers the exposed braze surface.

BACKGROUND

The field of the disclosure relates generally to braze joints for metal alloys, and more specifically, to thermal control of a braze process.

For at least some known components fabricated in whole or in part from metal alloys, cracks or defects in the alloy may occur during normal use of the component. For example, at least some known rotary machines use stainless steels and nickel-base, cobalt-base, and iron-base superalloys in components used in the hot flow path of the rotary machine during operation. The hot flow path subjects the components to thermal and/or mechanical stresses and strains. Accordingly, when a crack or defect occurs in the alloys of these components, the repaired crack or defect must be able to similarly withstand the high temperatures, stresses, and strains of the hot flow path.

One known method of repairing a crack or defect in an alloy is to create a braze joint using a braze process. For some known nickel-based superalloys, such as Rene' N5, Rene' 108, CMSX-4®, and CMSX-6® (registered trademarks of Cannon Muskegon Corporation), use of a braze is the typical technique to salvage a damaged part. In a conventional braze process, a braze material is used to repair a defect in an existing component by filling the gap with the liquid or partially liquid braze material, then allowing the braze material to solidify. At least one known brazing method includes cleaning the defect surfaces to be joined, placing the component with the defect in a vacuum braze furnace, and heating the furnace to a target temperature so that the braze material becomes molten or partially molten, allowing the braze material to flow into the spaces that form the defect. The braze process may be used to fill a gap between two components to join them together or the braze material may be used to form a new component.

In at least some of the known braze processes for forming braze joints described above, as the braze material begins to cool after the braze material has filled the defect in the component, solidification shrinkage occurs within the joint. Additionally, in at least some known braze joints, as the braze material cools, the braze material closer to the surface of the metal alloy cools faster than the braze material deeper into the defect. This differential cooling, when combined with the solidification shrinkage, can induce solidification defects, such as braze joints with a high degree of porosity and/or hot cracking. In at least some known braze processes, porosities are likely to form when the gap filled with braze material is greater than 0.1 mm and the braze material is a blend of a superalloy powder and a braze filler of a much lower melting point. In at least some known braze processes, hot cracking is likely to occur when the gap filled with braze material is less than 0.1 mm and the braze material is pure braze filler. These defects in the braze joint can reduce tensile strength and shorten creep life and fatigue life of the braze joint, leading to increased wear on the alloy-containing component, which can cause a forced outage of a turbine or additional wear on other internal components. These issues associated with defects in the braze joint can be especially problematic for components designed to be used in high stress areas, such as within the hot flow path of a rotary engine.

BRIEF DESCRIPTION

In one aspect, a system for creating a braze joint is provided. The system includes an environment operable to reach a braze temperature sufficient to melt at least a portion of a braze material. The system also includes a component within the environment, the component including a base having a base surface, a recess depending from the base surface into the base to an inner edge, and a braze material within the recess and forming a cap above the base surface. The braze material fills the recess from the cap to the inner edge. The cap has an exposed braze surface. The system also includes an insulation layer that at least partially covers the exposed braze surface.

In another aspect, a method for brazing a recess defined within a base is provided. The recess depends from a surface of the base into the base to an inner edge. The method includes creating a cap of braze material above the recess. The cap has an exposed braze surface. The method further includes positioning a thermal insulation layer over the exposed braze surface. The method also includes heating the braze material within an environment to create at least partially molten braze material. The method further includes cooling the at least partially molten braze material to form a solid braze joint within the recess.

In another aspect, a method for brazing a recess defined within a base is provided. The recess depends from a base surface of the base into the base to an inner edge. The method includes supplying at least partially molten braze material from a cap into the recess to the inner edge. The method also includes extracting heat from a location on the base, the location being closer to the inner edge of the recess than to the cap.

DETAILED DESCRIPTION

Unless otherwise indicated, approximating language, such as “generally,” “substantially,” and “about,” as used herein indicates that the term so modified may apply to only an approximate degree, as would be recognized by one of ordinary skill in the art, rather than to an absolute or perfect degree. Accordingly, a value modified by a term or terms such as “about,” “approximately,” and “substantially” is not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be identified. Such ranges may be combined and/or interchanged, and include all the sub-ranges contained therein unless context or language indicates otherwise. Additionally, unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, for example, 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.

The systems and methods described herein relate to creating a braze joint within a component. Specifically, in an exemplary embodiment, the system includes an environment operable to reach a braze temperature sufficient to melt at least a portion of a braze material. The system also includes a component within the environment, the component including a base having a base surface, a recess depending from the base surface into the base to an inner edge, and a braze material within the recess and forming a cap above the base surface. The braze material fills the recess from the cap to the inner edge. The cap has an exposed braze surface. In some embodiments, the system also includes an insulation layer that at least partially covers the exposed braze surface of the cap. After the environment is heated to the brazing temperature, the system facilitates less rapid heat dissipation from the exposed braze surface of the cap, as compared to a system without the insulation layer. Additionally or alternatively, the system includes a cooling system operable to extract heat from the base at a location closer to the inner edge of the recess than to the cap, which facilitates more rapid cooling of the braze joint compared to the exposed braze surface of the cap. Accordingly, the system facilitates creating the braze joint having fewer or no solidification defects within the recess, relative to the cap extending above the base surface, during the braze process.

FIG.1is a schematic view of an exemplary rotary machine100, i.e., a turbomachine, and more specifically a turbine engine. In the exemplary embodiment, rotary machine100is a gas turbine engine. Alternatively, rotary machine may be any other turbine engine and/or rotary machine, including, without limitation, a steam turbine engine, a gas turbofan aircraft engine, other aircraft engine, a wind turbine, a compressor, and a pump. In the exemplary embodiment, turbine engine100includes an intake section102, a compressor section104that is coupled downstream from intake section102, a combustor section106that is coupled downstream from compressor section104, a turbine section108that is coupled downstream from combustor section106, and an exhaust section110that is coupled downstream from turbine section108. Turbine section108is coupled to compressor section104via a rotor shaft112. It should be noted that, as used herein, the term “couple” is not limited to a direct mechanical, thermal, electrical, and/or flow communication connection between components, but may also include an indirect mechanical, thermal, electrical, and/or flow communication connection between multiple components. In the exemplary embodiment, combustor section106includes a plurality of combustors114. Combustor section106is coupled to compressor section104such that each combustor114is in flow communication with the compressor section104. Rotor shaft112is further coupled to a load116such as, but not limited to, an electrical generator and/or a mechanical drive application. In the exemplary embodiment, each of compressor section104and turbine section108includes at least one rotor assembly118that is coupled to rotor shaft112. Each rotor assembly118of turbine section108includes a plurality of circumferentially arranged, radially extending turbine blades119.

In operation, intake section102channels air120towards compressor section104. Compressor section104compresses inlet air120to higher pressures prior to discharging compressed air122towards combustor section106. Compressed air122is channeled to combustor section106where it is mixed with fuel (not shown) and burned to generate high temperature combustion gases124. Combustion gases124are channeled downstream towards turbine section108and impinge upon turbine blades119, converting thermal energy to mechanical rotational energy that is used to drive rotor assembly118about a longitudinal axis126. Often, combustor section106and turbine section108are referred to as a hot gas section109of turbine engine100. Exhaust gases128then discharge through exhaust section110to ambient atmosphere.

In some embodiments, during operation of turbine engine100, components204of hot gas section109, such as but not limited to turbine blades119, which may include stator vanes (not shown) and shrouds (not shown), can be exposed to temperatures as high as, for example, 1250 degrees Celsius, creating heat stresses. In turbine section108, components204are also subjected to mechanical stresses during operation, such as stresses from high speed rotation and the push of high-speed hot gases from combustor106. Such extreme operating conditions can cause cracks due to creep and/or fatigue and other defects to form within components204of hot gas section109, requiring repair.

FIG.2is a cross-sectional view of a system200for creating a braze joint202within one or more of components204. Although component204is described as a component of rotary machine100for purposes of illustration, it should be understood that system200is also contemplated for creating a braze joint in any suitable component204in a wide variety of applications, and is not limited to use with components of rotary machine100described herein.

In some embodiments, component204is formed from a metal alloy used within the hot gas section109or the combustor106of turbine engine100. In some such embodiments, component204is fabricated from a cobalt-base or a nickel-base superalloy. For example, component204may be fabricated from a single crystalline nickel-based superalloy, such as CMSX-4®. In alternative embodiments, component204is formed from any alloy that can be brazed using the systems and methods described herein.

System200includes an environment206for creating braze joint202. In some embodiments, environment206is a cavity defined within a heating compartment208. In the exemplary embodiment, heating compartment208is a vacuum furnace configured to supply both heat and vacuum to the cavity during the brazing process. For example, heating compartment208is configured to supply uniform temperatures across environment206, and to pull sufficient vacuum within environment206to remove at least some gases present in environment206. In an embodiment, such gases include oxygen, nitrogen, carbon dioxide, water vapor, and methane. In alternative embodiments, environment206is any suitable environment that allows the braze joint to be formed within component204as described herein.

Component204includes a base210having a base surface212and a recess214depending inwardly a recess depth216from base surface212to an inner edge224. In the exemplary embodiment, recess214represents a defect, such as a crack, in base210that may occur during normal use of component204. Inner edge224represents the innermost or deepest extent of the crack from base surface212. For example, in embodiments where component204is formed from a metal alloy used within the hot gas section109of turbine engine100, recess214may be formed due to the combination of rotational stress, force from rapidly flowing hot gas stream and/or cyclic thermomechanical strain on component204. In alternative embodiments, recess214may have been formed by another process, such as, intentionally or unintentionally during a casting or machining process for component204or a joint bonding two separately-formed components204together.

Braze joint202is formed from a braze material218. In one embodiment, braze material218includes a pure braze filler alloy, such as DF-4B diffusion braze alloy. The braze filler alloy may include one or more of aluminum, silicon, copper, silver, germanium, gold, nickel, cobalt and boron. In the exemplary embodiment, the braze alloy is a multi-component eutectic with relatively low melting point compared to the component204. For example, braze alloys used for components204formed from cobalt-base and nickel-base superalloys typically have a melting temperature less than 1120 degrees Celsius, and, more specifically, between 900 and 1100 degrees Celsius. In another embodiment, braze material218includes a blend of a braze powder and a braze filler alloy. The braze powder is typically a superalloy for component204and has a higher strength and a higher melting point compared to the braze filler alloy. As such, at certain temperatures, the braze alloy is molten while the braze powder is solid, creating a partially molten braze material218. In alternative embodiments, the braze material218may consist entirely or substantially of a braze filler alloy, or may comprise other material that allows the brazing joint202to form as described herein.

In an embodiment, braze material218comprises a braze filler alloy and a braze powder that are mixed with a binder to create a braze paste. For example, but not by way of limitation, the braze filler alloy and the braze powder are mixed with eight percent binder. The braze paste is semi-solid, which, in some embodiments, allows braze material218to be poured or injected into recess214. Such filling techniques are particularly suited for recesses214wider than 0.1 millimeter. In alternative embodiments, braze paste or pure braze filler alloy may be placed above recess214to create a cap220and braze material218is allowed to flow into recess by capillary effect. Such a filling technique is particularly suited for recesses214equal to or narrower than 0.1 millimeter.

In some embodiments, during the brazing process, environment206is heated to a brazing temperature. In some embodiments, the environment206is held at the brazing temperature for 10 minutes to 120 minutes. In some such embodiments, environment206is held at the brazing temperature for 20 minutes to 40 minutes, and in some such embodiments, for 30 minutes. Alternatively, environment206is kept at brazing temperature for any suitable length of time. The brazing temperature is lower than the melting temperature of component204and high enough to cause braze material218to become molten, or partially molten, as described above. In the exemplary embodiment, in which braze material218comprises a braze paste, at the brazing temperature, the braze alloy melts while the braze powder remains solid, creating a partially-molten braze material218. In some such embodiments, before environment206is heated to the brazing temperature, solid or paste braze material218is placed into recess214to fill recess from inner edge224to base surface212. In some such embodiments, additional braze material218is placed above base surface212to create cap220. Cap220is in fluid communication with braze material218in recess214. Braze material218is then heated to the brazing temperature, burning off most or all of any binder present and causing braze material218to become at least partially molten.

As described above, in alternative embodiments, braze paste or pure braze alloy may be placed above recess214to create a cap220and braze material218is allowed to flow into recess214by capillary effect. The loading of recess214may occur at room temperature or may occur by heating environment206to a brazing temperature. In an exemplary embodiment, braze material218is heated to the brazing temperature, creating an exposed braze surface222on at least partially-molten cap220and a contact angle219between the partially-molten braze material218and recess214. In some such embodiments, pure braze filler wets base surface212, inner edge224and the other surfaces of recess214and creates contact angle219of less than 90 degrees. In further embodiments, contact angle219is less than or equal to 30 degrees, allowing the braze material to spread over the inner edge224and other surfaces of recess214and drawing braze material218into recess214by capillary effect. In alternative embodiments, braze material218is completely melted at the braze temperature. In alternative or additional embodiments, braze material218is placed on base surface212over recess214in its partially-molten state, and is allowed to feed the recess214by capillary effect. In further embodiments, the braze material218may fill only a portion of recess214such that cap220is drawn into recess214once the braze material is heated to braze temperature in environment206.

In some embodiments, after braze material218reaches the brazing temperature, becomes at least partially molten, and fully fills the recess, the temperature in environment206is lowered and braze material218is allowed to cool to solidify braze material218, creating braze joint202within recess214. In some embodiments, solidification of braze material218causes braze material218to shrink, which can lead to solidification defects228in braze joint202. Some such solidification defects228include a high porosity (both in quantity and size) in the solid braze joint202, as illustrated by pores227inFIG.2. Other solidification defects228include linear indications, or cracks, as illustrated by linear indication229. In some embodiments, as base210and braze material218begin cool, a first portion230of braze material218located at or near exposed braze surface222decreases in temperature more rapidly than a second portion232of braze material218located at or near inner edge224. When one portion of braze material218cools faster than another portion, such as first portion230cooling faster in environment206than second portion232, the solidification shrinkage can cause defects228to form. In this exemplary embodiment, by first portion230cooling faster than second portion232, solidification defects228form within solidified braze material218near second portion232. When component204including braze joint202is returned to service, at least some such known solidification defects228result in reduced tensile strength and a shorter creep life and fatigue life of the braze joint202.

In some embodiments, the size of cap220compared to the size of braze joint202can affect an ability of cap220to feed shrinkage of braze material218within recess214during cooling. In some such embodiments, a ratio of modulus of cap220to the modulus of braze joint202can be used to characterize how effectively cap220feeds braze joint202, where modulus is defined as volume of a geometrical body divided by the heat dissipation area of the geometrical body. For example, if the modulus ratio is less than 1.0, braze material218in cap220starts and completes solidification earlier than braze material218in recess214while cooling in environment206. In one embodiment, a ratio of the modulus of cap220to the modulus of braze joint202greater than 1.0 effectively feeds braze material218into recess214to at least partially compensate for shrinkage during cooling. In some embodiments, a ratio of the modulus of cap220to the modulus of braze joint202greater than 1.1 effectively feeds braze material218into recess214during cooling to at least partially compensate for shrinkage and decrease solidification defects228. In further embodiments, a ratio of the modulus of cap220to the modulus of braze joint202greater than 1.5 particularly effectively feeds braze material218into recess214during cooling to at least partially compensate for shrinkage and decrease solidification defects228. In alternative embodiments, a ratio of the modulus of cap220to the modulus of braze joint202greater than 1.5 feeds braze material218into recess214during cooling to completely compensate for shrinkage and eliminate solidification defects228in braze joint202. Additionally or alternatively, increasing contact angle219at base surface212effectively increases the modulus of cap220, increasing feeding of braze material218from cap220to recess214during cooling to at least partially compensate for shrinkage. In various embodiments, the size of cap220and contact angle219are varied to increase feeding capability of cap220into recess214during cooling.

FIG.3is a cross-sectional view of another exemplary embodiment of a system for creating braze joint202within component204, designated system300. System300is similar to system200, and, accordingly, like components are labeled the same as for system200. System300differs from system200in that system300includes a thermal insulation layer302that at least partially covers exposed braze surface222of cap220of braze material218. In the exemplary embodiment, thermal insulation layer302completely covers cap220and a portion of base surface212. Like system200, in system300braze joint202is created by heating braze material218to a brazing temperature, causing braze material218to become at least partially molten and allowing braze material218to enter recess214. In some embodiments of system300, before heating braze material218to the brazing temperature, or after braze material218is made at least partially molten, thermal insulation layer302is placed over exposed braze surface222such that thermal insulation layer302at least partially covers exposed braze surface222.

Thermal insulation layer302may include any material that allows the thermal insulation layer302to function as described herein. In some embodiments, the thermal insulation layer302is formed from one or more of ceramic material, ceramic fiber, mineral wool, polycrystalline fiber, silica cloth, and any combinations thereof.

Similar to system200, in the exemplary embodiment of system300, once component204has been heated in environment206for sufficient time to create at least partially molten braze material218, environment206is allowed to cool from the brazing temperature. As environment206cools, base210and braze material218also begin to cool, allowing braze material218to solidify forming braze joint202. Unlike system200, in some embodiments, thermal insulation layer302causes first portion230, located near cap220and braze surface222, to cool more slowly than second portion232, located near inner edge224. Because of the temperature differential between first portion230and second portion232, solidification of braze material218starts and completes earlier near second portion232than first portion230. Accordingly, as shrinkage occurs in braze material218during solidification, any solidification defects228that form in braze material218occur closer to first portion230than to second portion232. More specifically, in the exemplary embodiment, thermal insulation layer302causes solidification defects228to primarily form in cap220near exposed braze surface222. Before component204is returned to service, cap220is removed or is otherwise not designed to contribute to a strength of braze joint202. Accordingly, in some embodiments, solidification defects228in first portion230of braze material218do not significantly affect a performance of braze joint202.

Like with system200, in system300, varying the size of cap220compared to the size of braze joint202, in combination with applying thermal insulation layer302, can affect the ability of cap220to feed braze material218into recess214to at least partially compensate for shrinkage during cooling. In some such embodiments, the ratio of modulus of cap220to the modulus of braze joint202can be used to characterize how effectively cap220feeds braze joint202. In some further embodiments, thermal insulation layer302increases the modulus of cap220, and thus its ratio to the modulus of braze joint202, when compared to the corresponding ratio for caps220without an insulation layer, such as the cap220illustrated in system200. In some such embodiments, thermal insulation layer302allows for cap220having a smaller width to provide the same amount of feeding of braze joint202as cap220having a larger width but without an insulation layer.

FIG.4is a cross-sectional view of another exemplary embodiment of a system for creating braze joint202within component204, designated system400. System400is similar to system200, and accordingly, like components are labeled the same as system200. System400differs from system200in that system400includes a cooling device401operable to extract heat from a location403on base210. More specifically, location403is closer to inner edge224of recess214than to cap220.

In the exemplary embodiment, cooling device401includes a thermal conduction element402in contact with location403. Also in the exemplary embodiment, location403is a second base surface404of base210located opposite base surface212. However, it will be appreciated that location403may be any location that is closer to inner edge224of recess214than to cap220. In other words, location403is selected such that cooling device401enhances the heat extraction of second portion232of braze material218while having less effect on first portion230of braze material218.

Similar to system200, in the exemplary embodiment of system400, after component204has been heated in environment206for sufficient time to create at least partially molten braze material218, environment206is allowed to cool from the brazing temperature. In the exemplary embodiment, thermal conduction element402is configured to extract heat from location403of base210while environment206is cooling. In alternative embodiments, thermal conduction element402is configured to extract heat from location403of base210while environment206is actively heating environment206and then while environment206is cooling. Because thermal conduction element402is located closer to second portion232than to first portion230, braze material218reduces in temperature faster near second portion232than first portion230. Because of the temperature differential between first portion230and second portion232, solidification of braze material218occurs more rapidly near second portion232than first portion230. Accordingly, as shrinkage occurs in braze material218during solidification, solidification defects228that form in braze material218occur closer to first portion230than to second portion232. In the exemplary embodiment, solidification defects228primarily form in cap220near exposed braze surface222. Before component204is returned to service, cap220is removed or is otherwise not designed to contribute to a strength of braze joint202. Accordingly, solidification defects228in first portion230of braze material218do not significantly affect a performance of braze joint202.

Thermal conduction element402includes any thermal conductive material and/or system that allows thermal conduction element to function as described herein. In some embodiments, thermal conduction element402includes a heat exchanger. Thermal conduction element402may be, for example, a plate-fin heat exchanger, a plate heat exchanger, or a tube heat exchanger. In still further embodiments, thermal conductive element402includes a graphite plate with embedded cooling channels connected to a cooling media. In alternative embodiments, cooling device401includes any suitable structure that enables system400to function as described herein.

FIG.5is a cross-sectional view of another exemplary system for creating braze joint202within component204, designated system500. System500is similar to system400, and accordingly, like components are labeled the same as system400. System500differs from system400in that cooling device401is implemented as an impingement manifold502configured to direct a fluid504into impingement with base210at location403. As above, location403is selected such that fluid504impinges a portion of base210closer to inner edge224of recess214, and second portion232, than to cap220, exposed braze surface222, and first portion230. In the illustrated embodiment, location403is again second base surface404of base210located opposite base surface212. Alternatively, location403may be any location that is closer to inner edge224of recess214than to cap220.

Similar to system200, in the exemplary embodiment of system500, after component204has been heated in environment206for sufficient time to create at least partially molten braze material218, environment206is allowed to cool from the brazing temperature. Impingement manifold502is configured to direct fluid504to extract heat from location403of base210while environment206is cooling. Because fluid504impinges on base210at location403closer to second portion232than to first portion230, braze material218reduces in temperature faster near second portion232than first portion230. Because of the temperature differential between first portion230and second portion232, solidification of braze material218occurs more rapidly near second portion232than first portion230. Accordingly, as shrinkage occurs in braze material218during solidification, solidification defects228that form in braze material218occur closer to first portion230than to second portion232. In the exemplary embodiment, solidification defects228primarily form in cap220near exposed braze surface222. Before component204is returned to service, cap220is removed or is otherwise not designed to contribute to a strength of braze joint202. Accordingly, solidification defects228in first portion230of braze material218do not significantly affect a performance of braze joint202.

Impingement manifold502, and fluid504directed thereby, includes any thermal convective system and/or process that allows the cooling device401to function as described herein. In some embodiments, impingement manifold502comprises jet nozzles connected to a source of fluid504such as a pressurized gas. In some such embodiments, fluid504includes one or more of argon, helium, hydrogen, and/or nitrogen.

Although insulation layer302(shown inFIG.3) and cooling device401(shown inFIGS.4and5) are illustrated above as being implemented separately, in some embodiments additional advantages in reducing or eliminating solidification defects228from braze joint202are obtained by implementing insulation layer302and cooling device401concurrently. In other words, during the cool-down phase after environment206is heated to the brazing temperature, insulation layer302at least partially covers exposed braze surface222of cap220concurrently with cooling device401(e.g., thermal conduction element402or impingement manifold502) operating to extract heat from location403of base210, further facilitating more rapid solidification of braze material218near second portion232than first portion230.

FIG.6is a flow diagram of an exemplary method600of brazing a recess defined within a base, such as brazing recess214defined within base210(shown inFIGS.2-5). The recess depends from a base surface, such as base surface212, into the base to an inner edge, such as inner edge224. Method600includes creating602a cap, such as cap220, of braze material, such as braze material218, above the recess. The cap has an exposed braze surface, such as exposed braze surface222. Method600further includes positioning604a thermal insulation layer, such as thermal insulation layer302, over the exposed braze surface. Method600further includes heating606the braze material within an environment, such as environment206, to create at least partially molten braze material. Method600further includes cooling608the at least partially molten braze material to form a solid braze joint, such as braze joint202.

In some embodiments in which the braze material is a braze paste comprising a braze filler alloy, a braze powder, and a binder, creating602a cap of braze material above the recess further includes filling the recess from the surface to the inner edge with the braze paste such that the cap and braze paste in the recess are in fluid communication. In further embodiments, heating606the braze material within an environment to create at least partially molten braze material further includes filling the recess to the inner edge with at least partially molten braze material from the cap via capillary effect. In certain embodiments, cooling608the at least partially molten braze material to form the braze joint further comprises passively allowing the environment to cool.

In some embodiments, cooling608the at least partially molten braze material includes cooling a location on the base closer to the inner edge than to the cap. In particular embodiments, cooling608the at least partially molten braze material further includes solidifying the cap. In some such embodiments, the solid cap has greater porosity than the solid braze joint.

FIG.7is a flow diagram of another exemplary method700of brazing a recess defined within a base, such as brazing recess214within base210(shown inFIGS.2-5). The recess depends from a base surface, such as base surface212, into the base to an inner edge, such as inner edge224. Method700includes supplying702at least partially molten braze material, such as braze material218, from a cap, such as cap220, into the recess to the inner edge. Method700also includes extracting heat704from the base at a location on the base, the location situated closer to the inner edge of the base than to the base surface.

In some embodiments, extracting heat704from the base includes conductive cooling at the location using a heat exchanger. In other embodiments, extracting heat704from the base includes convective cooling at the location using impingement cooling.

In some embodiments, method700further includes positioning at least partially solid braze material above the recess within a environment, such as environment206. In some such embodiments, supplying602the at least partially molten braze material from the cap to the recess further includes heating the environment to a brazing temperature to create the at least partially molten braze material.

In particular embodiments, method700further includes positioning a thermal insulation layer, such as thermal insulation layer302, over an exposed braze surface, such as exposed braze surface222, on the cap before supplying the at least partially molten braze material and extracting heat from the base.

The above systems and methods for creating a braze joint within a component facilitates creating braze joints within a component having less or no defects formed within the joint during the braze process, thus decreasing the need to replace the braze joint and increasing the longevity of a component with the braze joint. The systems and methods produce a high degree of metallurgical integrity, which imparts superior and reliable mechanical capabilities to the braze joint. The systems and methods may be particularly advantageous for components used in extreme heat and high-mechanical stress environments, such as components subjected to the high temperatures and rotational stress in the hot gas section of gas turbines.

Additionally, an exemplary technical effect of the systems and methods described herein includes at least one of: (a) reducing defects within a braze joint due to solidification shrinkage; (b) reducing the amount of braze material needed to feed a recess when forming a braze joint in a component; and (c) increase the life of the braze joint.

Exemplary embodiments of systems and methods for brazing a joint within a component are described above in detail. The methods and systems are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the systems and methods may also be used in combination with many types of components, and are not limited to practice only with the gas turbine engine as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other joint-brazing applications.