Products and methods

Abstract

To provide a heat-treated product which is formed at least partially by lamination molding, and a heat-treated product production method.SOLUTION: Provided is a product which is composed of a lamination molded component obtained by successively joining the layers of metal powder. A brazing material 110 is arranged on at least a part of an outer surface 105 of the component. The brazing material 110 is located at an estimated crack location 120 of the outer surface. One or more cracks which are formed at the outer surface 105 upon heat treatment are filled with the brazing material 110. The lamination molded component comprises a metallic material of a precipitation hardening nickel-base superalloy to form a γ' phase.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to heat-treated products formed at least in part by additive manufacturing and methods for making heat-treated products. More particularly, aspects of the invention relate to components and products, such as turbine components, that have been heat-treated to fill cracks formed during heat treatment, improve performance, extend part life, and reduce scrap. [Background technology]

[0002] Metal additive manufacturing allows manufacturers to create final metal products that often outperform those made using traditional machining and casting techniques. These methods can sometimes produce components that cannot be made using traditional methods. These methods also offer the advantage of significantly reducing manufacturing costs. These products contribute to cost savings in their end-use applications due to one or more of: light weight, high strength, superior functionality, and precision fit. With regard to turbines, particularly gas or steam turbines, a wide variety of components or portions thereof can be manufactured by additive manufacturing, including, for example, turbine components selected from the group consisting of hot gas path components, shrouds, blades (or buckets), nozzles (vanes), and seals. In some examples, combustor and hot gas path components can be manufactured by additive manufacturing processes to allow for the formation of complex geometries without the need for extensive post-processing, including, but not limited to, nozzle bars, micromixer plenums, combustion flex tips, and microchannel cooling shrouds.

[0003] While there are many advantages realized with additive manufacturing as opposed to some traditional manufacturing techniques, additively manufactured products can have complex surface features. These complex geometries can be prone to cracking during heat treatment. Therefore, while additive manufacturing can achieve many benefits, the resulting cracks can negatively impact performance in terms of mechanical integrity, fluid dynamics, and leakage, and in some cases, gaps and cracks can compromise flow integrity, rendering the part unusable. When repair measures are taken to avoid scrapping the product, the component typically must first undergo a fluoride ion cleaning, an advanced cleaning process to remove oxides from the cracks. Finally, a high-temperature vacuum brazing process may be used to repair surface cracks.

[0004] Thus, there is a need in the art for a treatment to reduce cracking in additively manufactured parts that must be heat treated after the building process. Summary of the Invention

[0005] In one aspect, the product comprises an additively manufactured part formed by sequentially joining layers of metal powder. A brazing material is disposed on at least a portion of an outer surface of the part. The brazing material is disposed on the outer surface at anticipated crack locations. One or more cracks formed in the outer surface during heat treatment are filled with the brazing material. The additively manufactured part includes a metallic material that is a precipitation-hardened nickel-based superalloy and forms the gamma prime phase.

[0006] In another aspect, a method for manufacturing a part is provided. The method includes a plurality of steps. A forming step is used to form an additively manufactured part by sequentially joining layers of metal powder using an additive manufacturing process. A identifying step is for identifying anticipated crack locations on the surface of the additively manufactured part. A applying step is for applying a brazing material to the anticipated crack locations. A heating step is for heating the additively manufactured part to one or more desired heating temperatures for one or more desired heating or dwell periods. A cooling step is for cooling the additively manufactured part to one or more desired cooling temperatures for one or more desired cooling or dwell periods. The brazing material fills cracks formed during one or more of the heating steps.

[0007] In yet another aspect, a method for manufacturing a part includes a plurality of steps. The forming step forms an additively manufactured part by sequentially joining layers of metal powder using an additive manufacturing process. The metal powder comprises a nickel-based superalloy, a cobalt-based superalloy, or an iron-based alloy, and the additive manufacturing process is selected from the group consisting of direct metal laser melting, direct metal laser sintering, selective laser melting, or electron beam melting. The identifying step identifies anticipated crack locations on the surface of the additively manufactured part. The applying step applies a brazing filler material to the anticipated crack locations. The brazing filler material (or paste) comprises a nickel-based superalloy material or a cobalt-based superalloy material and a binder. The heating step heats the additively manufactured part to one or more desired heating temperatures for one or more desired heating dwell periods. The cooling step cools the additively manufactured part to one or more desired cooling temperatures for one or more desired cooling dwell periods. The brazing filler material fills cracks formed in one or more of the heating steps, and the additively manufactured part is a gas turbine component or a steam turbine component. The metal powder comprises a precipitation hardened nickel-based superalloy, which forms the gamma prime phase.

[0008] Other features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a component according to one aspect of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram illustrating a portion of an additively manufactured part processed according to the present disclosure. [Figure 3] FIG. 1 illustrates an example heat treatment process for an additively manufactured part processed according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure provides a method for filling cracks that occur in a component during a heat treatment process. The component may be a gas or steam turbine component. In various aspects, the component is formed by one or more of a variety of additive manufacturing techniques, such as, for example, a component made by direct metal laser melting ("DMLM"). Representative examples of components include gas or steam turbine components manufactured by additive manufacturing (e.g., DMLM), including, but not limited to, combustors, combustion liners, transition pieces, hot gas path components, shrouds, blades (or buckets), nozzles (vanes), seals, and combinations thereof. In some examples, components include honeycombs, bucket tips, seals, and fins. In some specific examples, combustor and hot gas path components can be manufactured by additive manufacturing processes, and components with complex geometries, particularly those with microchannels or other complex internal passages for cooling, including, but not limited to, nozzle bars, micromixer plenums, combustion flex tips, and microchannel-cooled shrouds, can be formed without the need for extensive post-processing.

[0011] In the present disclosure, a part or portion thereof is formed by an additive manufacturing or "three-dimensional" (3D) printing process. The additively manufactured part or portion is further processed by application of a brazing material, which is provided at predetermined locations to fill cracks formed during subsequent heat treatment processes, particularly at locations on the part where cracks are anticipated or where cracks have previously occurred in similar parts. In this method, the brazing material is applied and brazed using an appropriate brazing technique as required by the particular brazing material and base material.

[0012] Additive manufacturing generally includes any manufacturing method for creating and / or forming net-shape or near-net-shape structures. As used herein, the term "near-net" refers to a structure, such as a part, being formed with a geometry and size that closely approximates the structure's final geometry and size, requiring little or no machining or processing after the additive manufacturing process. As used herein, the term "net" refers to a structure formed with a geometry and size that does not require machining or processing. Structures formed by additive manufacturing processes include any suitable geometry, such as, but not limited to, squares, rectangles, triangles, circles, semicircles, ellipses, trapezoids, octagons, pyramids, geometries with formed features, other geometries, or combinations thereof. For example, additive manufacturing processes may include forming cooling features.

[0013] Generally, additive manufacturing processes involve spraying material onto a support or substrate / base in a predetermined area and selectively melting or sintering the material with a process such as a laser or electron beam. A two-dimensional slice of a predetermined design file or three-dimensional file, for example, can be utilized from a computer-aided design program to form the part or portion. The material may also be in the form of an atomized powder. Examples of additive manufacturing or three-dimensional printing processes include, but are not limited to, direct metal laser melting ("DMLM"), direct metal laser sintering ("DMLS"), selective laser sintering ("SLS"), selective laser melting ("SLM"), electron beam melting ("EBM"), and processes known to those skilled in the art, such as "powder blown" additive manufacturing processes commonly known as laser cladding, laser powder welding ("LPF"), direct metal laser deposition ("DMLD"), laser metal deposition ("LMD"), or laser metal forming ("LMF"). As used herein, the term "three-dimensional printing process" refers to the processes described above as well as any suitable current or future-developed process that involves building up materials layer by layer. Materials suitable for three-dimensional printing processes include, but are not limited to, plastics, thermoplastics, metals, metallic materials, ceramic materials, other suitable materials, or combinations thereof. Specific examples of materials suitable for atomized powder include, but are not limited to, stainless steel, tool steel, cobalt chromium, titanium, nickel, aluminum, alloys thereof, and combinations thereof.

[0014] Thus, in various examples, methods for manufacturing a component or part according to the present disclosure include providing a metal powder to a substrate surface, heating the metal powder to a temperature sufficient to bond at least a portion of the metal powder to form an initial layer, and sequentially forming additional layers on the initial layer to form the component or part. Heating the metal powder may include any suitable method, such as, for example, controllably directing a focused energy source toward the metal powder. Suitable focused energy sources include, but are not limited to, a laser device, an electron beam device, or a combination thereof. The parameters of the focused energy source depend on the material of the metal powder used to form the component or part and / or the desired thickness of each layer of the build.

[0015] In some particular embodiments, the material of the atomized powder includes metal alloys, including nickel- and cobalt-based superalloys, stainless and alloy steels, and titanium, aluminum, and vanadium alloys. A suitable example of a cobalt-based alloy may have the formula (in wt.%): Co0.39-0.41-Cr0.19-0.21-Ni0.14-0.16-Fe0.113-0.205-Mo0.06-0.08-Mn0.015-0.025 (commercially available as Co-Cr-Ni alloy). Suitable examples of nickel-based alloys may have the formula (in mass %) of Fe-0.50-0.55Ni-0.17-0.21Cr-0.028-0.033Mo-0.0475-0.055Nb-0.01Co-0.0035Mn-0.002-0.008Cu-0.0065-0.0115Al-0.003Ti (commercially available as Inconel 718) or the formula (in mass %) of Ni-0.20-0.23Cr-0.05Fe-0.08-0.10Mo-0.0315-0.0415Nb+Ta-0.01Co-0.005Mn-0.004Al-0.004Ti (commercially available as Inconel 625). Suitable examples of titanium-based alloys include those known by the trade names Ti-6Al-4Va and Aluminum 6061. In various non-limiting examples, the component may comprise any suitable material, such as stainless steel, a nickel-based alloy, an iron-based alloy, or other suitable metal or metal material. In one embodiment, the component, or portions thereof, are formed from stainless steel and / or a nickel-based alloy, such as Hastelloy® X, the foregoing materials being exemplary only and not limiting.In some exemplary embodiments, the printed part material is selected from CoCrMo (Co-28Cr-6Mo) and Haynes 282 (Ni-20Cr-10Co-8Mo-1.5Al-2Ti) or high strength precipitation hardened Ni superalloys such as Rene 108 (Ni-23Cr-11.5Fe-4.2P-6.4Si), Rene 80 (60Ni-14Cr-9.5Co-5Ti-4Mo-4W-3Al-0.17C-0.015B-0.03Zr), Inconel 738 (Ni-16Cr-8.5Co-1.7Mo-3.5Al-3.5Ti-1.7Ta-2.5W-0.05Zr-0.09C-0.01B-2Nb) and CM247 (Ni-0.07C-8.1Cr-9.2Co-9.5W-0.5Mo-3.2Ta-5.6Al-0.7Ti-1.4Hf-0.015B-0.015Zr). The metal powder may be a nickel-based superalloy, a cobalt-based superalloy, an iron-based superalloy, or a combination thereof.

[0016] Once a component or portion thereof is formed, it is further processed by application of a braze material. As used herein, the terms "braze," "brazing," "braze film," "braze material," "braze paste," and "braze coating" refer to the surface treatment of a component or part, such as a turbine component, where the process does not involve joining of workpieces, but rather involves applying a braze material directly to the surface of the component to achieve the benefits of the resulting braze layer or film.

[0017] In some embodiments of the present invention, vacuum brazing techniques are used. As used herein, vacuum brazing refers to a process that offers the advantages of producing clean, excellent flux-free brazed joints and surfaces of high integrity and strength. The process is carried out in a vacuum chamber vessel at a typical pressure of 8×10 torr or less for about 10 to 30 minutes, typically maintaining the workpieces at a uniform temperature ranging from about 1500°F to about 2370°F (815°C to 1300°C) under continuous heat, reducing or eliminating stresses that may otherwise be introduced by heating and cooling cycles.

[0018] Thus, in one non-limiting example, brazing is accomplished as a single-step vacuum braze at a pressure of 8×10 torr or less, with a brazing temperature of about 1500° F. to about 2370° F., about 1500° F. to about 1800° F., about 2000° F. to about 2370° F., about 1800° F. to about 2370° F., about 1800° F. to about 2100° F., or any suitable combination, subcombination, range, or subrange therein. In one non-limiting embodiment, the brazing duration is about 1 minute to about 4 hours, about 1 hour to about 4 hours, about 1 hour to about 3 hours, or any suitable combination, subcombination, range, or subrange therein.

[0019] Referring now to the drawings, FIG. 1 is a schematic diagram illustrating a portion of an additively manufactured part 100 processed in accordance with the present disclosure. In this representative example, a brazing material 110 is applied or disposed on at least a portion of the part 100, such as the outer surface 105. The brazing material 110 is located at a predicted crack site 120 that may develop during heat treatment. Generally, the maximum process temperature is determined by the requirements of the base metal, although some compromises may be necessary from a brazing perspective. If the brazing alloy normally requires a low temperature, strong flow and spreading of the brazing alloy on the base metal can be expected. To limit this phenomenon, a flow stopper in the form of a spray can be used to completely cover the brazing paste and confine the brazing flow to areas affected by crack formation. The high cooling rates of direct metal laser melting (DMLM) produce fine grains. Therefore, parts or components made by DMLM typically exhibit reduced creep strength along with increased tensile strength, hardness, and low-cycle fatigue resistance. Subsequent annealing or recrystallization processes can achieve a good combination of ductility, strength, and creep strength in direct metal laser melted parts. However, this heat treatment (annealing / recrystallization) process can also lead to cracks in the AM part. This is particularly evident in DMLM components made from precipitation-hardened Ni superalloys such as Rene 80, Rene 108, CM247, or Inconel 738. Traditionally, these are cast alloys that are very strong at high operating temperatures due to the precipitation of a strengthening γ' phase. In contrast to traditional manufacturing by casting, AM by DMLM does not produce γ' precipitates in the as-built component or part. Instead, γ' precipitates only form during the first heat treatment after DMLM. The formation of this strengthening phase occurs in a temperature range where the component is brittle above room temperature. Furthermore, the phase transformation induces additional internal stresses, which, combined with embrittlement, can lead to severe cracking. The approach of the present invention is to selectively place brazing filler material 110 at these predicted crack locations, allowing the brazing filler to fill and bond the crack surfaces of the base material of the component 100 in situ. Therefore, cracks can be repaired during the same heat treatment cycle while the part is still in the high-temperature vacuum furnace. On the one hand, no oxide layer is formed when cracks occur, ensuring excellent brazing wetting.On the other hand, there is a significant economic benefit since the labor and cost of the fluoride ion cleaning process required to remove oxides from the cracks and subsequent braze repair cycles can be avoided.

[0020] Part 100, or a portion thereof, in some examples is characterized as having braze material 110 applied to one or more of the interior surfaces (as long as accessible for application of braze paste and braze stoppers) and exterior surfaces of a metal substrate, where the surfaces may include one or more of flat surfaces, corners, curves, and contours, and may further include surface cracks or other crevices that extend into the substrate of part 100. Referring again to FIG. 1 , part 100 has predicted crack locations 120, which may be in known crack-prone areas or areas of complex geometry. In this method, as shown in FIG. 1 , braze material 110 is applied after the additive manufacturing process of part 100.

[0021] In the present method, the braze material 110 includes known or novel low or high melting point materials, particularly for use with nickel-based superalloys, where the braze material is particularly metallurgically compatible with such nickel-based superalloys. For example, the braze material may include metal alloys and superalloys, including, but not limited to, nickel-based and cobalt-based superalloys, alloys, and combinations thereof. Suitable examples of nickel-based alloys may have the formula (by weight) of Ni-14Cr-10Co-3.5Al-2.5Ta-2.75B-0.05Y (commercially available as Amdry DF-4B from Oerlikon Metco, Inc., Westbury, New York, USA) or the formula (by weight) of Ni-19Cr-10Si (commercially available as BNi-5 from a number of sources, including Wall Colmonoy, Inc., Madison Heights, Michigan, USA). Of course, other base materials may be used to form additively manufactured parts, including other brazing materials of choice, and may be other than high melting point, low melting point, or high / low melting point.

[0022] The manufacturing method proposed in this application, including an adapted heat treatment, is designed to simultaneously fulfill two requirements: on the one hand, ensuring the microstructural requirements of the DMLM member or component through proper recrystallization (ReX), and, on the other hand, allowing simultaneous field braze repairs in case of crack formation in the predicted locations due to the temperature cycle.

[0023] Figure 2 shows a schematic diagram of a portion of an additively manufactured part 100 processed using standard procedures. The part 100 has been heat treated and has a crack 122 formed at the expected crack location 120 (shown in Figure 1). Such crack formation during the first heat treatment cycle is highly likely in precipitation-hardened Ni superalloys processed by DMLM. The proposed in-situ repair method discloses a way to repair such cracks in situ during the same heat treatment cycle as they occur.

[0024] Referring to Figure 3, the heat treatment process involves heating the component to a first temperature (T1) and holding the component at that first temperature for a predetermined first period (t1), which must be long enough to ensure a uniform temperature profile throughout the component and evaporation of the binder contained in the brazing paste / material. If the component is made of a precipitation-hardened Ni superalloy, the first holding temperature (T1) should be approximately 20-100 K lower than the onset temperature of γ' formation, which is typically accompanied by a decrease in the thermal expansion coefficient of the DMLM material. Once the component reaches a uniform temperature after t1, the component 100 is rapidly heated to a second temperature (T2) at a high heating rate (v2) > 20 K / min. This high heating rate minimizes the formation of γ' phase in the intermediate, low-ductility temperature range, where the DMLM component is brittle and at high risk of severe cracking. Even with such a high heating rate (v2), the formation of macrocracks often cannot be completely avoided. Macrocracks form, especially where there is a significant amount of frozen-in internal stress from processing or where the component design is not optimized, resulting in localized stress peaks. Often, cracks requiring repair occur during the temperature increase from T1 to temperature T2. In a preferred embodiment, T2 is approximately 850°C or higher and is selected to be sufficiently high so that the high-strength DMLM material becomes ductile again and can relieve the residual internal stresses in the DMLM component. At the same time, T2 is kept below the solidus temperature of the given braze alloy material to avoid partial flow of braze material into cracks 122 that may form during the transition from T1 to T2. The heating or dwell time t2 at T2 again ensures a homogeneous temperature profile in the DMLM component before the initiation of the further temperature increase to T3. At the same time, the majority of the residual stresses are relieved after the hold or dwell time t2. The temperature is then increased at a rate v3 of about 15-30 K / min to a temperature level T3, which is held at T3 for a dwell time t3, which is set above the liquidus temperature of the brazing filler material 120. Ideally, the temperature level T3 is selected to be about 30-100 K lower than the final recrystallization temperature T4 of the DMLM alloy. As the temperature is increased from T3 to T4, the brazing filler material 120 becomes liquid. If cracks 122 have formed earlier in the same heat treatment cycle, the brazing filler material can flow into and fill the cracks 122 at this stage.The brazing filler material 120 remains in a liquid state during a dwell time at the recrystallization temperature T4. In contrast to the previous temperature increases, this increase is performed at a slow heating rate v4 < 5 K / min to avoid overheating, which could result in localized incipient melting. The part is held at T4 for the recrystallization dwell time t4, which must be long enough to achieve the desired recrystallized microstructure of the DMLM component. At the same time, the brazing filler material 120 completely fills the crack 122, allowing braze diffusion to occur and resulting in a more homogeneous elemental distribution in the crack-repair zone. In some cases, the recrystallization temperature T4 may exceed the typical temperature recommended by braze suppliers. A beneficial side effect of such a high temperature T4 is increased diffusivity, significantly reducing the formation of harmful brittle phases in the brazed joint. Following the recrystallization and crack-repair of the DMLM component at T4, the part is slowly cooled at a rate v5 < -5 K / min to another intermediate temperature T5 and held there for the dwell time t5, which is set at a level at which the brazing filler resolidifies. T5 should not be set more than 50 K below the solidus temperature of the braze, and slow cooling from T4 to T5 prevents the repair braze joint from failing due to rapid cooling of the still-ductile braze material. After T5 is reached, the cooling rate v6 to ambient temperature is increased to a value within the range of -15 K / min to -50 K / min, while continuing to meet other microstructural requirements of the part until ambient temperature is finally reached. In this example, the horizontal axis is time and the vertical axis is temperature, with the first temperature T1 being lower than the second temperature T2, the third temperature T3 being higher than the second temperature T2, and the final recrystallization temperature T4 being higher than T3. This five-stage heat treatment is only an example; fewer than three or more heating temperatures and one intermediate cooling temperature may be used depending on the specific part or material being used.

[0025] In various embodiments, the methods described herein provide parts with crack-sealed properties compared to as-built and heat-treated AM parts. The methods disclosed herein can also seal surface cracks present on external and internal surfaces that are artifacts of the AM process. The treated parts exhibit improved surface properties that improve resistance to corrosion, oxidation, and erosion, as well as extended lifespan. At the same time, the proposed methods significantly improve AM DMLM production yields, especially for parts made from high-strength, precipitation-hardened Ni superalloys, which are difficult to manufacture without significant defects.

[0026] Thus, technical advantages of the present method and heat treatment include improved quality, higher yield, and longer life of AM parts. Another advantage is that no separate braze repair cycle is required, reducing costs associated with repairs. Furthermore, because the cracks are formed in a vacuum atmosphere and are not oxidized, costly and time-consuming crack cleaning processes are not required. Another advantage is the option to select high-strength powder materials for AM parts, including nickel-based superalloys with a high content of the strengthening γ' phase. These parts can be heat treated with braze material to seal cracks and other defects in accordance with the present disclosure.

[0027] While the present invention has been described with reference to preferred embodiments, it will be apparent to those skilled in the art that various modifications may be made within the scope of the invention, and that equivalents may be substituted for certain elements. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope of the invention. Therefore, it is not intended that the invention be limited to the particular embodiment contemplated as the best mode contemplated for carrying out this invention, but rather that the invention will include all embodiments falling within the scope of the appended claims. [Explanation of symbols]

[0028] 100 additively manufactured parts 105 Outer surface 110 Brazing materials 120 Expected crack location 122 Crack T1 First temperature T2 Second temperature T3 Third temperature T4 Final recrystallization temperature T5 intermediate temperature t1 First period t2 residence time t3 Residence time t4 Recrystallization residence time t5 residence time

Claims

1. A method for manufacturing a component (100), the method comprising: forming an additively manufactured part (100) by an additive manufacturing process in which successive layers of metal powder are bonded together; identifying predicted crack locations (120) on a surface (105) of the additively manufactured part (100); applying a brazing material (110) to the predicted crack location (120), the brazing material (110) being selectively disposed only at the predicted crack location (120); heating the additively manufactured part (100) to one or more desired heating temperatures (T1-T4) for one or more desired heating or dwell periods (t1-t4), wherein the heating comprises heating the additively manufactured part (100) to a first temperature (T1) and holding the additively manufactured part (100) at the first temperature (T1) for a first dwell period (t1), and then heating the additively manufactured part (100) to a second temperature (T2) and holding the additively manufactured part (100) at the second temperature (T2) for a second dwell period (t2), wherein the first temperature (T1) is lower than the second temperature (T2), and the second temperature (T2) is less than a solidus temperature of the brazing material (110); cooling the additively manufactured part (100) to a cooling temperature (T5) for a cooling dwell time (t5); It contains The method wherein the brazing material (110) fills cracks (122) formed during the heating step.

2. The method of claim 1 , wherein the metal powder is selected from the group consisting of nickel-based superalloys, cobalt-based superalloys, iron-based superalloys, and combinations thereof.

3. The method of claim 1, wherein the additively manufactured component comprises a precipitation hardened nickel-based superalloy and forms a gamma prime phase.

4. 4. The method of claim 3, wherein the first temperature (T1) is 20 to 100 K lower than the onset temperature of γ' formation.

5. The method of claim 1, wherein the braze material comprises a nickel-based alloy or a cobalt-based alloy.

6. 2. The method of claim 1, wherein the heating further comprises heating the additively manufactured part (100) to a second temperature (T2) and holding the additively manufactured part (100) at the second temperature (T2) for a second residence time (t2), followed by heating the additively manufactured part (100) to a third temperature (T3), wherein the second temperature (T2) is lower than the third temperature (T3), and the third temperature (T3) is 30 K to 100 K lower than a recrystallization temperature of the additively manufactured part.

7. 7. The method of claim 6, wherein the heating further comprises heating the additively manufactured part (100) to a third temperature (T3) followed by heating the additively manufactured part (100) to a fourth temperature (T4), wherein the third temperature (T3) is lower than the fourth temperature (T4) and the recrystallization temperature of the additively manufactured part occurs at the fourth temperature (T4).

8. The method of claim 7, wherein the braze material (110) remains in a liquid state during a fourth residence time (t4) at a fourth temperature (T4).

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