A method of crack repair for an additively manufactured nickel-based superalloy component

Abstract

The application relates to a crack repairing method for additive manufacturing of a nickel-based high-temperature alloy piece, and relates to the technical field of high-temperature alloys. The main technical scheme is as follows: filler powder and solder powder are used to repair cracks of the additive manufacturing nickel-based high-temperature alloy piece; the chemical components of the solder powder include the following in percentage by weight: Cr 11.0-17.0wt%, W 5.0-9.0wt%, B 1-4wt%, C<=0.06wt%, Co<=0.1wt%, and Ni is the rest; the chemical components of the filler include the following in percentage by weight: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C<=0.2wt%, B<=0.1wt%, Hf<=2wt%, and Ni is the rest; and the chemical components of the additive manufacturing nickel-based high-temperature alloy include the following in percentage by weight: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C<=0.2wt%, B<=0.1wt%, Hf<=2wt%, and Ni is the rest. The application is mainly used for solving the problem of repairing and remanufacturing of cracks of the additive manufacturing nickel-based high-temperature alloy piece, and has important application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-temperature alloys, further relates to a welding material product for repairing cracks of a high-temperature alloy part and a crack repairing method, in particular to a crack repairing method for an additive manufacturing nickel-based high-temperature alloy part. BACKGROUND

[0002] Additive manufacturing high-temperature alloy is a kind of high-temperature alloy prepared by means of laser melting technology or synchronous powder feeding technology. Such alloy parts have the advantages of short manufacturing cycle and high shape adaptability.

[0003] However, when the content of γ' forming elements such as Al and Ti in the chemical composition of the additive manufacturing high-temperature alloy is high, a large amount of γ' precipitated phase in the alloy is easily precipitated, which can easily cause strain aging cracks during the manufacturing process, thereby greatly restricting the application of high Al and Ti content bottom strengthening additive manufacturing high-temperature alloy.

[0004] If the cracks in such parts can be repaired, the additive manufacturing high-temperature alloy crack repair remanufacturing can be realized, thereby greatly improving the qualified rate of part production and having a wide application prospect. SUMMARY

[0005] Therefore, the present application provides a crack repairing method for an additive manufacturing nickel-based high-temperature alloy part, which mainly aims to realize the crack repair of additive manufacturing high-temperature alloy.

[0006] To achieve the above-mentioned purpose, the present application mainly provides the following technical solutions:

[0007] On the one hand, the present application provides a crack repairing method for an additive manufacturing nickel-based high-temperature alloy part, wherein filler powder and solder powder are used to repair the cracks of the additive manufacturing nickel-based high-temperature alloy part;

[0008] wherein the chemical composition of the solder powder includes, in terms of weight percentage, Cr 11.0-17.0wt%, W 5.0-9.0wt%, B 1-4wt%, C≤0.06wt%, Co≤0.1wt%, and Ni as the balance;

[0009] wherein the chemical composition of the filler includes, in terms of weight percentage, Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C≤0.2wt%, B≤0.1wt%, Hf≤2wt%, and Ni as the balance;

[0010] The chemical composition of the additive manufacturing nickel-based superalloy is as follows in terms of weight percentage: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C≤0.2wt%, B≤0.1wt%, Hf≤2wt%, and Ni is the balance.

[0011] Preferably, in the solder powder: the content of B is 2-3.5wt%; and / or the chemical composition of the filler powder is the same as that of the additive manufacturing nickel-based superalloy part; and / or the solder powder is spherical and / or near-spherical, and the particle size is -325 mesh; and / or the filler powder is spherical and / or near-spherical, and the particle size is -140-+325 mesh.

[0012] Preferably, the preparation of the solder powder comprises:

[0013] The solder alloy is subjected to gas atomization treatment to obtain alloy powder; the alloy powder is subjected to sieving treatment, and the alloy powder of a set particle size is selected as the solder powder;

[0014] Preferably, the parameters of the gas atomization treatment are as follows: the smelting temperature is 1390-1590°C; the powder spraying temperature is 1410-1570°C; the atomization gas is an inert gas, preferably argon; and the atomization pressure is 2-10MPa.

[0015] Preferably, the preparation of the filler powder comprises:

[0016] The filler alloy is subjected to gas atomization treatment to obtain alloy powder; the alloy powder is subjected to sieving treatment, and the alloy powder of a set particle size is selected as the filler powder;

[0017] Preferably, the parameters of the gas atomization treatment are as follows: the smelting temperature is 1450-1620°C; the powder spraying temperature is 1440-1590°C; the atomization gas is an inert gas, preferably argon; and the atomization pressure is 2-10MPa.

[0018] Preferably, the crack repair method of the additive manufacturing nickel-based superalloy part comprises the following steps:

[0019] Step S1: press the first paste material into the crack of the additive manufacturing nickel-based superalloy part; wherein the first paste material comprises a filler powder, a solder powder, and a binder;

[0020] Step S2: apply the second paste material at the crack to cover the first paste material, and apply the second paste material at the area near the crack; wherein the second paste material comprises a solder powder and a binder;

[0021] Step S3: applying a flow inhibitor at a surrounding position of the second paste material on the additively manufactured nickel-based superalloy piece;

[0022] Step S4: drying treatment and crack repair treatment are performed on the additively manufactured nickel-based superalloy piece after the flow inhibitor is applied, to obtain the additively manufactured superalloy piece after crack repair.

[0023] Preferably, in the first paste material, the content of the adhesive is not more than 8wt%; preferably, the adhesive is selected from a water-based adhesive; and / or in the first paste material, the mass of the solder powder accounts for 40-50wt% of the sum of the mass of the solder powder and the filler powder; and / or the preparation step of the first paste material comprises: mixing the filler powder with the solder powder to obtain a mixed powder; then adding the adhesive into the mixed powder and stirring to form the first paste material; and / or in the second paste material, the content of the adhesive is 8-14wt%.

[0024] Preferably, before the step S1, it further comprises a step S0: removing the oxide layer at the crack to be repaired on the additively manufactured nickel-based superalloy piece; and / or after the step S4, it further comprises a step S5: polishing the residual solder on the additively manufactured superalloy piece after crack repair.

[0025] Preferably, in the step S1: the first paste material is pressed into the crack of the additively manufactured nickel-based superalloy piece, and after compaction, the first paste material overflowing to the non-welding position outside the crack needs to be cleaned; and / or in the step S2: the area near the crack refers to an area within 2mm from the crack; and / or in the step S2, the amount of the second paste material applied is not less than 2 times the volume of the crack; and / or in the step S3, the distance between the flow inhibitor and the second paste material is not more than 2mm.

[0026] Preferably, in the step S4: the drying treatment is performed at a temperature of 80-150℃ for 1-3 hours; and / or after the drying treatment, the surface solder on the additively manufactured nickel-based superalloy piece needs to be trimmed; and / or the crack repair treatment is performed in a vacuum heat treatment furnace or a vacuum brazing furnace; preferably, the temperature of the crack repair treatment is 1150-1240℃, and the holding time is 10-30 minutes; preferably, after the holding time ends, cooling treatment is performed by furnace cooling or argon filling; preferably, before the cooling treatment, the vacuum pressure in the furnace is not higher than 4×10 -2 Pa.

[0027] Preferably, the crack repair method of the additive manufacturing nickel-based superalloy part is used to repair cracks with a crack gap size of no more than 1.2 mm; and / or the crack in the repaired additive manufacturing superalloy part is eliminated, and there is no unwelding defect at the repair site.

[0028] Compared with the prior art, the crack repair method of the additive manufacturing nickel-based superalloy part has at least the following beneficial effects:

[0029] The embodiment of the present application provides a crack repair method of an additive manufacturing nickel-based superalloy part, which is used to solve the crack repair problem of an additive manufacturing nickel-based superalloy part with high Al and Ti γ' strengthening. The embodiment of the present application adopts a method of combining filler powder and solder powder for crack repair. Specifically, the powder of the alloy body composition is used as the filler powder. In order to improve the internal repair density of the large gap crack, a certain amount of low-melting-point high-wetting solder powder is mixed in the filler, combined with tight compaction, to ensure that a sufficient amount of powder is preserved in the crack gap to avoid local unwelding defects. During the repair process, the mixed powder (filler powder and solder powder) of the present application acts as the matrix skeleton in the joint, which can avoid the unwelding condition in the central part when the crack gap to be repaired is wide, compared with directly using the filler powder as the skeleton or only adding a small amount of mixed powder skeleton with solder powder. In addition, since the base material is a high Al and Ti precipitation-strengthening type additive manufacturing superalloy, there is still a large residual internal stress after heat treatment. In this embodiment of the present application, the filler powder with the same composition as the additive manufacturing superalloy part is used to maximize the matching of the welding material and the matrix, thereby avoiding further stress cracking. In addition, the Cr element and W element, which are also present in the base material, are added to the chemical composition of the solder powder as strengthening elements to improve the matching. The amount of Cr element added is more to obtain better oxidation resistance, and the amount of W element added is moderate to avoid excessive W leading to reduced flowability, thereby reducing the weldability. In addition, by limiting the content of Co element, the crack sensitivity can be reduced. The B element in the solder powder plays a role in reducing the melting point of the solder. The B element is added together with the matrix element Ni and the strengthening elements Cr and W to ensure that the weld seam has strength and organizational stability while improving the solder wettability, flowability and gap filling property, thereby reducing the weld defects and improving the weld strength.

[0030] Further, when the filler powder, solder powder and adhesive are blended to form the first paste-like material for pressing into the crack, the amount of adhesive needs to be strictly controlled. If the amount of adhesive is excessive, the density of the weld seam will be poor, resulting in welding defects, so that the crack cannot be successfully repaired. If the content of the adhesive is insufficient, the flowability of the solder paste will be too poor, and the solidification will be too fast, making it difficult to press into the crack.

[0031] Further, the embodiment of the present application selects different particle sizes for the solder powder and the filler powder, the solder powder is finer, and the filler powder is coarser, so that the solder powder can fill the gaps between the filler powder, make full use of the existing space to further realize greater space utilization, and fill more powder into the crack. In addition, the use of different particle sizes of powder also increases the actual amount of powder added in the crack, further ensuring the repair ability of the wide gap crack.

[0032] Further, the crack repair method for the additive manufacturing nickel-based superalloy part provided by the embodiment of the present application directly places the low-melting-point high-wetting solder powder (which is mixed with the adhesive to form the second paste) outside the crack after the first paste is pressed into the crack, so as to fully utilize the excellent flow and gap filling performance of the solder in the repair process to penetrate into the micro-gap channel in the crack and fill the entire crack. The residual solder outside the crack can provide better surface quality after polishing after welding. In summary, the solder powder (the second paste) coated outside the crack has excellent flowability, wettability and gap filling performance, and can assist in penetrating into the residual gap in the crack, while ensuring the surface quality and improving the internal quality of the joint.

[0033] In summary, the embodiment of the present application provides a crack repair method for an additive manufacturing nickel-based superalloy part, which uses alloy powder with the same composition as the additive manufacturing superalloy base material as filler, cooperates with high-wetting solder, and uses a vacuum heat treatment furnace or a vacuum brazing furnace with wide adaptability and low cost. In the case of meeting the use requirements of the additive manufacturing part, the method greatly improves the qualified rate and reduces the production cost through repair and remanufacturing, and has great economic value and application value.

[0034] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application and can be implemented according to the content of the specification, the following will be described in detail with the preferred embodiments of the present application and with the help of the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a macroscopic picture of the additive manufacturing nickel-based superalloy part before crack repair in Example 1.

[0036] Figure 2 It is an X-ray photo of the crack site of the additive manufacturing nickel-based superalloy part before crack repair in Example 1.

[0037] Figure 3 It is a macroscopic photo of the original crack site of the additive manufacturing nickel-based superalloy part after crack repair in Example 1.

[0038] Figure 4Fluoroscopy of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 1.

[0039] Figure 5 X-ray of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 1.

[0040] Figure 6 Macro photograph of the additively manufactured nickel-base superalloy piece before crack repair in Example 2.

[0041] Figure 7 Macro photograph of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 2.

[0042] Figure 8 Fluoroscopy of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 2.

[0043] Figure 9 X-ray of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 2.

[0044] Figure 10 X-ray of the crack site of the additively manufactured nickel-base superalloy piece before crack repair in Example 3.

[0045] Figure 11 Macro photograph of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 3.

[0046] Figure 12 X-ray of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Example 3.

[0047] Figure 13 Fluoroscopy of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Comparative Example 1.

[0048] Figure 14 Fluoroscopy of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Comparative Example 2

[0049] Figure 15 Macro photograph of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Comparative Example 3

[0050] Figure 16 X-ray of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Comparative Example 4

[0051] Figure 17 X-ray of the original crack site of the additively manufactured nickel-base superalloy piece after crack repair in Comparative Example 5 DETAILED DESCRIPTION

[0052] To further clarify the technical means and effects taken by the present application to achieve the predetermined inventive purpose, the specific embodiments, structures, features and effects thereof according to the present application are described in detail below in conjunction with the drawings and preferred embodiments. In the following description, different "an embodiment" or "embodiments" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0053] The crack repair method of the additive manufacturing nickel-based superalloy part according to the embodiment of the present application comprises the following steps:

[0054] Step S0: removing the oxide layer at the crack to be repaired of the additive manufacturing nickel-based superalloy part.

[0055] Step S1: pressing the first paste material into the crack of the additive manufacturing nickel-based superalloy part; wherein the first paste material comprises filler powder, solder powder and adhesive.

[0056] In this step, the filler powder and the solder powder are mechanically mixed to form a mixed powder, the proportion of the solder powder in the mixed powder is 40-50%, then the adhesive is added to the mixed powder and stirred uniformly to form the first paste material, the addition amount of the adhesive should not exceed 8% of the total weight of the mixed powder and the adhesive, then the first paste material is pressed into the original crack of the additive manufacturing nickel-based superalloy part, and the first paste material at the non-welding position outside the crack is cleaned up after compaction (it should be noted that the inside of the crack is the welding position, and the outside of the crack is the non-welding position).

[0057] Preferably, the "pressing" method includes using a syringe or a dispensing machine to inject the first paste material into the crack, or directly using a clean dust-free cloth to dip the solder paste and press it in, but is not limited thereto, as long as the first paste material is pressed into the crack of the additive manufacturing nickel-based superalloy part.

[0058] It should be noted that since the present application is used for repairing super-large gap cracks, the proportion of solder powder is strictly required, too high proportion of solder powder will lead to insufficient support of the filler skeleton, and easy to appear the whole loss of the filler material, resulting in visual inspection of meat. Too low proportion of solder powder will lead to insufficient filling shrinkage of the solder, and easy to appear a large number of micropores, resulting in dense point display in fluorescence inspection. Therefore, the present application controls the proportion of solder powder in the mixed powder to be 40-50%.

[0059] Preferably, the chemical composition of the solder powder includes: Cr 11.0-17.0wt%, W 5.0-9.0wt%, B 1-4wt%, C≤0.06wt%, Co≤0.1wt%, and Ni is the balance, in terms of weight percentage.

[0060] The chemical composition of the filler powder is as follows in terms of weight percentage: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C≤0.2wt%, B≤0.1wt%, Hf≤2wt%, and Ni is the balance.

[0061] The chemical composition of the additive manufacturing nickel-based superalloy is as follows in terms of weight percentage: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C≤0.2wt%, B≤0.1wt%, Hf≤2wt%, and Ni is the balance.

[0062] Preferably, the chemical composition of the filler powder is the same as that of the additive manufacturing nickel-based superalloy part.

[0063] Preferably, the solder powder is spherical and / or near-spherical, and the particle size is -325 mesh (particles that can pass through a 325 mesh sieve).

[0064] Preferably, the filler powder is spherical and / or near-spherical, and the particle size is (-140-+325) mesh. In this context, "-" means "sieve under", "+" means "sieve above", -140-+325 mesh indicates particles between 140 mesh and 325 mesh.

[0065] Preferably, the solder powder is prepared by gas atomization, and the gas atomization process parameters are as follows: melting temperature is 1390-1590℃, powder spraying temperature is 1410-1570℃, atomizing gas is argon, and atomizing pressure is 2-10MPa; the prepared alloy powder is sieved to obtain alloy powder with a particle size of -325 mesh, which is the solder powder.

[0066] Preferably, the filler powder is prepared by gas atomization, and the gas atomization process parameters are as follows: melting temperature is 1450-1620℃, powder spraying temperature is 1440-1590℃, atomizing gas is argon, and atomizing pressure is 2-10MPa; the prepared alloy powder is sieved to obtain alloy powder with a particle size of (-140-+325) mesh, which is the filler powder.

[0067] Step S2: applying a second paste material to cover the first paste material at the crack and at the area near the crack; wherein the second paste material comprises solder powder and adhesive.

[0068] Preferably, in this step, the adhesive is added to the solder powder and stirred evenly to form a second paste material, the amount of adhesive added accounts for 8% to 14% of the total weight of the solder powder and the adhesive, and then the second paste material is applied to the outer surface of the paste mixed solder and the metal base material outside the original crack within a range of 2 mm, and the total application amount should not be less than 2 times the volume of the original crack, so as to ensure that there is enough solder to flow into the framework (filler) at high temperature, so as to avoid welding defects caused by insufficient solder.

[0069] Step S3: Apply a flow resistance agent to the surrounding position of the second paste material on the additive manufacturing nickel-based high-temperature alloy part.

[0070] Preferably, in this step, the flow resistance agent is applied to the surrounding of the paste solder, and the distance between the flow resistance agent and the second paste material should not exceed 2 mm.

[0071] Step S4: Dry treatment and crack repair treatment are performed on the additive manufacturing nickel-based high-temperature alloy part after the flow resistance agent is applied, to obtain a crack-repaired additive manufacturing high-temperature alloy part.

[0072] Preferably, in this step, the additive manufacturing nickel-based high-temperature alloy part is placed in an oven at 80-150°C for 1-3 hours for drying, and the surface solder (surface paste) is appropriately trimmed; then the part to be repaired is placed in a vacuum heat treatment furnace or a vacuum brazing furnace for crack repair, wherein the temperature of the crack repair treatment is (1150-1240) °C, and the holding time is 10-30 minutes. It should be noted that the above-mentioned crack repair treatment temperature is selected without exceeding the limit temperature that the alloy can withstand, and without damaging the alloy itself, while ensuring that the melting and gap filling effect of the solder meet the repair requirements. In addition, the holding time is short, which is more economical, and the short holding time can reduce the impact on the alloy. Although the time is short, it is sufficient to ensure the full flow and gap filling of the solder. After welding, the furnace is cooled or argon is filled for cooling, and the vacuum pressure in the furnace before cooling is not higher than 4×10 -2 Pa, so as to ensure that the part, the filler and the solder are not oxidized, and the solder has good wettability to the base material and the filler during the repair process.

[0073] Step S5: The residual solder on the outside of the original crack part of the crack-repaired additive manufacturing high-temperature alloy part is polished to the original part surface state.

[0074] The adhesive mentioned in the above steps of the embodiment is a water-based adhesive or an oily adhesive, and a water-based adhesive (such as Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is preferred.

[0075] The crack repair method of the embodiment of the present application can repair the crack of the additive manufacturing nickel-based high-temperature alloy part with a gap of not more than 1.2 mm, and the original crack is eliminated after repair, and there is no un-welding defect at the repair site.

[0076] The present application is further described below in combination with preferred embodiments:

[0077] Embodiment 1

[0078] The present embodiment provides a crack repair method for an additive manufacturing nickel-based high-temperature alloy part, wherein,

[0079] The additive manufacturing nickel-based high-temperature alloy part used in the present embodiment is a part with a chemical composition of Ni-8Cr-8Co-7.85W-6Ta-5.5Al-0.7Ti-2Mo-0.08C-0.015B printed by using a selective laser melting technology, as shown in Figure 1 and Figure 2 As shown, there is a through crack on the part, and the gap at the widest part of the crack is 1 mm.

[0080] The filler powder used in the present embodiment is an alloy powder with the same chemical composition as the part prepared by using a gas atomization method. The gas atomization process parameters are: melting temperature 1560℃, powder spraying temperature 1540℃, atomizing gas argon, and atomizing pressure 9MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of (-140~+325) mesh, which is the filler powder of the present embodiment.

[0081] The solder powder used in the present embodiment is an alloy powder with a chemical composition of Ni-15Cr-7W-3B prepared by using a gas atomization method. The gas atomization process parameters are: melting temperature 1510℃, powder spraying temperature 1490℃, atomizing gas argon, and atomizing pressure 8MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of -325 mesh, which is the solder powder of the present embodiment.

[0082] The crack repair method of the present embodiment comprises the following steps:

[0083] Step S0: Remove the oxide layer at the crack to be repaired by sandblasting and polishing.

[0084] Step S1 : The filler powder and the solder powder are mechanically mixed in a ratio of 60%:40% to form a mixed powder, and then a water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of the binder added is 7wt% of the total weight of the mixed powder and the binder. Then the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and after compaction, the paste mixed solder outside the crack is cleaned up.

[0085] Step S2: The water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) is added to the solder powder and stirred uniformly to form a second paste. The amount of the binder added is 12wt% of the total weight of the solder powder and the binder. Then the second paste is applied to the outer surface of the first paste and the metal base material outside the original crack within a range of 2mm, and the total application amount is 2.5 times the volume of the original crack.

[0086] Step S3: The flow resistance agent is applied around the second paste, and the distance between the flow resistance agent and the second paste is 1.5mm at the farthest.

[0087] Step S4: The additive manufacturing nickel-based superalloy part with the above-mentioned coating is placed in a 110°C oven for drying for 1.5 hours, and the positions where the surface solder is not uniformly applied are slightly trimmed; then the additive manufacturing nickel-based superalloy part is placed in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1160°C, the holding time is 10 minutes, and after the holding is completed, argon is filled for cooling to below 80°C, and the vacuum pressure in the furnace before cooling is always not higher than 4x10 - 2 Pa.

[0088] Step S5: After the additive manufacturing nickel-based superalloy part after crack repair is taken out of the furnace, the residual solder on the outside of the original crack part is polished to the original surface state of the part.

[0089] wherein, Figure 3 is a macroscopic photograph of the original crack part of the additive manufacturing nickel-based superalloy part after crack repair in this embodiment. The original crack part of the additive manufacturing nickel-based superalloy part after crack repair is subjected to fluorescent penetration and X-ray inspection, as shown in Figure 4 and Figure 5 From Figures 3-5 , it can be seen that: no defect is found, it is confirmed that the original crack has been eliminated, there is no un-welded defect, and successful repair is achieved.

[0090] Example 2

[0091] The embodiment provides a crack repairing method of an additive manufacturing nickel-based superalloy part, wherein,

[0092] The additive manufacturing nickel-based superalloy part used in the embodiment is a part with a chemical composition of Ni-8Cr-8Co-8W-6Ta-5.5Al-0.7Ti-2Mo-0.1C-0.015B-1.4Hf printed by using a selective laser melting technology, as shown in Figure 6 As shown in the figure, the part has a through crack, and the gap of the widest part of the crack is 1.2 mm.

[0093] The filler powder used in the embodiment is an alloy powder with the same chemical composition as the part prepared by using a gas atomization method. The gas atomization process parameters are as follows: a smelting temperature of 1560 DEG C, a powder spraying temperature of 1540 DEG C, an atomizing gas of argon, and an atomizing pressure of 9 MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of (-140 to +325) mesh, which is the filler powder of the embodiment.

[0094] The solder powder used in the embodiment is an alloy powder with a chemical composition of Ni-16Cr-8W-2.5B prepared by using a gas atomization method. The gas atomization process parameters are as follows: a smelting temperature of 1540 DEG C, a powder spraying temperature of 1520 DEG C, an atomizing gas of argon, and an atomizing pressure of 8 MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of -325 mesh, which is the solder powder of the embodiment.

[0095] The crack repairing method of the embodiment comprises the following steps.

[0096] Step S0: The oxide layer at the crack to be repaired is removed by using sandblasting combined with polishing.

[0097] Step S1: The filler powder and the solder powder are mechanically mixed at a ratio of 50:50 to form a mixed powder, and then a water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The addition amount of the adhesive is 6wt% of the total weight of the mixed powder and the adhesive. Then, the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and the paste mixed solder at non-welding positions outside the crack is cleaned after compaction.

[0098] Step S2: add water-based binder (Nicrobraz s-binder produced by Wall Colmonoy) into the solder powder and stir evenly to form a second paste. The amount of binder added is 12wt% of the total weight of the solder powder and the binder. Then the second paste is applied to the outer surface of the first paste and the metal base material outside the original crack within a range of 2mm, and the total application amount is 3 times the volume of the original crack.

[0099] Step S3: apply a flow resistor around the second paste, and the distance between the flow resistor and the second paste is 1.6mm.

[0100] Step S4: place the additive manufacturing nickel-based superalloy part with the above-mentioned coating in a 110℃ oven for 1.5 hours, and slightly trim the unevenly coated surface solder; then place the additive manufacturing nickel-based superalloy part in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1230℃, the holding time is 30 minutes, and after holding, argon is filled to cool to below 80℃, and the vacuum pressure in the furnace before cooling is always not higher than 4×10 - 2 Pa.

[0101] Step S5: After the crack-repaired additive manufacturing nickel-based superalloy part is taken out of the furnace, the residual solder on the outside of the original crack part is polished to the original part surface state.

[0102] Figure 7 is a macro photograph of the original crack part of the crack-repaired additive manufacturing nickel-based superalloy part in this embodiment. Fluorescent penetration and X-ray inspection are performed on the original crack part of the crack-repaired additive manufacturing nickel-based superalloy part, as shown in Figure 8 and Figure 9 It can be seen that no defects are found, the original crack is confirmed to be eliminated, there are no un-welded defects, and successful repair is achieved.

[0103] Example 3

[0104] The embodiment provides a crack repair method for an additive manufacturing nickel-based superalloy part, wherein,

[0105] The additive manufacturing nickel-based superalloy part used in this embodiment is a part with a chemical composition of Ni-7Cr-7.5Co-8W-5Ta-4.5Al-1.1Ti-2.2Mo-0.12C-0.03B printed by selective laser melting technology, as shown in Figure 10 , and there is a through crack on the part, and the gap at the widest part of the crack is 1mm.

[0106] The filler powder used in the embodiment is an alloy powder with the same chemical composition as the part, prepared by gas atomization. The gas atomization process parameters are: smelting temperature 1560 DEG C, powder spraying temperature 1540 DEG C, atomizing gas argon, atomizing pressure 9 MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with particle size (-140-+325) mesh, which is the filler powder of the embodiment.

[0107] The solder powder used in the embodiment is an alloy powder with chemical composition of Ni-15Cr-5.5W-1.8B, prepared by gas atomization. The gas atomization process parameters are: smelting temperature 1545 DEG C, powder spraying temperature 1520 DEG C, atomizing gas argon, atomizing pressure 8 MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with particle size -325 mesh, which is the solder powder of the embodiment.

[0108] The crack repair method of the embodiment comprises the following steps:

[0109] Step S0: The oxide layer at the position to be repaired is removed by sandblasting and polishing.

[0110] Step S1: The filler powder and the solder powder are mechanically mixed in a ratio of 60:40 to form a mixed powder, and then a water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of adhesive added is 8wt% of the total weight of the mixed powder and the adhesive. Then the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and the paste mixed solder that has overflowed outside the crack is cleaned up after compaction.

[0111] Step S2: The water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the solder powder and stirred uniformly to form a second paste. The amount of adhesive added is 13wt% of the total weight of the solder powder and the adhesive. Then the second paste is applied to the outer surface of the first paste and the metal base material within 2mm outside the original crack, and the total amount of application is 3 times the volume of the original crack.

[0112] Step S3: The flow resistance agent is applied around the second paste, and the farthest distance between the flow resistance agent and the second paste is 1.5mm.

[0113] Step S4: The additive manufacturing nickel-based superalloy part with the above-mentioned coating is placed in a 120℃ oven for 1.5 hours for drying, and the unevenly coated positions of the surface solder are slightly trimmed; then the additive manufacturing nickel-based superalloy part is placed in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1240℃, the holding time is 12 minutes, and after the holding time ends, the furnace is cooled to below 80℃, and the vacuum pressure in the furnace before cooling is always not higher than 4×10 - 2 Pa.

[0114] Step S5: After the crack-repaired additive manufacturing nickel-based superalloy part is taken out of the furnace, the residual solder on the outside of the original crack part is polished to the original part surface state.

[0115] Figure 11 Figure 1 is a macro photograph of the original crack part of the additive manufacturing nickel-based superalloy part after crack repair in this embodiment, Figure 12 Figure 2 is an X-ray photograph of the original crack part of the additive manufacturing nickel-based superalloy part after crack repair in this embodiment. From Figure 11 and Figure 12 It can be seen that: no defect is found, the original crack is confirmed to be eliminated, there is no un-welded defect, and successful repair is achieved.

[0116] It should be noted that: compared with Example 3, the B content in the solder of Example 1 and Example 2 is more, therefore, the fluidity, wettability and gap filling property of the solder in Example 1 and Example 2 are better, which is more helpful to avoid defects and obtain a more dense weld structure.

[0117] Comparative Example 1

[0118] Comparative Example 1 provides a crack repair method for an additive manufacturing nickel-based superalloy part, wherein,

[0119] The additive manufacturing nickel-based superalloy part used in this embodiment is a part with a chemical composition of Ni-8Cr-8Co-8W-6Ta-5.5Al-0.7Ti-2Mo-0.1C-0.015B-1.4Hf printed by selective laser melting technology, and there is a through crack on the part, and the gap at the widest part of the crack is 1.2mm.

[0120] The filler powder used in this embodiment is an alloy powder with the same chemical composition as the part prepared by gas atomization method. The gas atomization process parameters are: melting temperature is 1560℃, powder spraying temperature is 1540℃, atomizing gas is argon, and atomizing pressure is 9MPa. The alloy powder obtained by atomization is sieved to obtain alloy powder with particle size of (-140~+325) mesh, which is the filler powder of this embodiment.

[0121] The solder powder used in the embodiment is an alloy powder with chemical composition of Ni-16Cr-8W-2.5B prepared by gas atomization method. The gas atomization process parameters are: smelting temperature of 1540°C, powder spraying temperature of 1520°C, atomizing gas of argon, and atomizing pressure of 8 MPa. The alloy powder obtained by atomization is sieved to obtain alloy powder with particle size of-325 mesh, which is the solder powder of the embodiment.

[0122] The crack repair method of the embodiment comprises the following steps:

[0123] Step S0: The oxidation layer at the position to be repaired is removed by sandblasting and polishing.

[0124] Step S1: The filler powder and the solder powder are mechanically mixed in a ratio of 50:50 to form a mixed powder, and then a water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of the binder added is 10% of the total weight of the mixed powder and the binder. Then, the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and the paste mixed solder that has overflowed outside the crack is cleaned after compaction.

[0125] Step S2: The water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) is added to the solder powder and stirred uniformly to form a second paste. The amount of the binder added is 12% of the total weight of the solder powder and the binder. Then, the second paste is applied to the outer surface of the first paste and the metal base material within a range of 2 mm outside the original crack, and the total application amount is 3 times the volume of the original crack.

[0126] Step S3: The flow resistance agent is applied around the second paste, and the farthest distance between the flow resistance agent and the second paste is 1.6 mm.

[0127] Step S4: The additive manufacturing nickel-based superalloy part coated with the above-mentioned coating is placed in a 110°C oven for drying for 1.5 hours, and the positions where the surface solder is not uniformly coated are slightly trimmed; then the additive manufacturing nickel-based superalloy part is placed in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1230°C, the holding time is 30 minutes, and after the holding time ends, argon is filled for cooling to below 80°C, and the vacuum pressure in the furnace before cooling is always not higher than 4×10 - 2 Pa.

[0128] Step S5: After the additive manufacturing nickel-based superalloy part with repaired cracks is discharged, the residual solder on the outside of the original crack site is polished to the original part surface state.

[0129] Referring to Figure 13 As shown, the original crack site of the repaired part is checked, and it is found that the original crack site presents local point display after fluorescent penetration, indicating that the compactness of the repaired site is poor, and there is a local non-welding defect. This is because the content of the adhesive in the paste-shaped mixed solder pressed into the crack exceeds 8%, resulting in poor compactness of the weld and welding defects, so that the crack is not successfully repaired.

[0130] Comparative Example 2

[0131] The embodiment provides a crack repair method of an additive manufacturing nickel-based superalloy part, wherein,

[0132] The additive manufacturing nickel-based superalloy part used in the embodiment is a part with a chemical composition of Ni-8Cr-8Co-8W-6Ta-5.5Al-0.7Ti-2Mo-0.1C-0.015B-1.4Hf printed by using a selective laser melting technology, and there is a through crack on the part, and the gap of the widest part of the crack is 1.2 mm.

[0133] The filler powder used in the embodiment is an alloy powder with the same chemical composition as the part prepared by using a gas atomization method. The gas atomization process parameters are: smelting temperature is 1560℃, powder spraying temperature is 1540℃, atomizing gas is argon, and atomizing pressure is 9MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of (-140~+325) mesh, which is the filler powder of the embodiment.

[0134] The solder powder used in the embodiment is an alloy powder with a chemical composition of Ni-16Cr-8W-2.5B prepared by using a gas atomization method. The gas atomization process parameters are: smelting temperature is 1540℃, powder spraying temperature is 1520℃, atomizing gas is argon, and atomizing pressure is 8MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of (-140~+325) mesh, which is the solder powder of the embodiment.

[0135] The crack repair method of the embodiment comprises the following steps:

[0136] Step S0: The oxide layer at the crack to be repaired is removed by sandblasting and polishing.

[0137] Step S1 : The filler powder and the solder powder are mechanically mixed in a ratio of 50%:50% to form a mixed powder, and then a water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of the binder added is 6% of the total weight of the mixed powder and the binder. Then the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and after compaction, the paste mixed solder outside the crack is cleaned up.

[0138] Step S2: The water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) is added to the solder powder and stirred uniformly to form a second paste. The amount of the binder added is 12% of the total weight of the solder powder and the binder. Then the second paste is applied to the outer surface of the first paste and the metal base material outside the original crack within a range of 2 mm, and the total application amount is 3 times the volume of the original crack.

[0139] Step S3: The flow resistance agent is applied around the second paste, and the distance between the flow resistance agent and the second paste is 1.6 mm.

[0140] Step S4: The additive manufacturing nickel-based superalloy part with the above-mentioned coating is placed in a 110°C oven for 1.5 hours for drying, and the positions where the surface solder is not uniformly applied are slightly trimmed; then the additive manufacturing nickel-based superalloy part is placed in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1230°C, the holding time is 30 minutes, and after the holding time ends, argon is filled for cooling to below 80°C. The vacuum pressure in the furnace before cooling is always not higher than 4x10 - 2 Pa.

[0141] Step S5: After the additive manufacturing nickel-based superalloy part after crack repair is taken out of the furnace, the residual solder on the outside of the original crack position of the metal is polished to the original surface state of the part.

[0142] As Figure 14 shown, the repaired part is checked at the original crack position, and it is found that the original crack position shows local linear display after fluorescent penetration, indicating that the density of the repaired position is poor, and there are local unwelding defects. This is because the particle size of the solder powder is not suitable, which leads to insufficient space utilization of the mixed solder, and then the total amount of the mixed solder pressed into the crack is less, which leads to poor density of the weld and welding defects, so that the crack cannot be successfully repaired.

[0143] Comparative Example 3

[0144] The comparative example provides a crack repair method of an additive manufacturing nickel-based superalloy part, wherein,

[0145] The additive manufacturing nickel-based superalloy part used in the comparative example is a part with a chemical composition of Ni-8Cr-8Co-7.85W-6Ta-5.5Al-0.7Ti-2Mo-0.08C-0.015B printed by using a selective laser melting technology, as shown in Figure 1 and Figure 2 As shown, there is a through crack on the part, and the gap of the widest part of the crack is 1 mm.

[0146] The filler powder used in the comparative example is an alloy powder with the same chemical composition as the part prepared by using a gas atomization method. The gas atomization process parameters are: smelting temperature is 1560℃, powder spraying temperature is 1540℃, atomizing gas is argon, and atomizing pressure is 9MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of (-140~+325) mesh, which is the filler powder of the present example.

[0147] The solder powder used in the comparative example is an alloy powder with a chemical composition of Ni-15Cr-7W-0.8B prepared by using a gas atomization method. The gas atomization process parameters are: smelting temperature is 1550℃, powder spraying temperature is 1530℃, atomizing gas is argon, and atomizing pressure is 8MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of -325 mesh, which is the solder powder of the present example.

[0148] The crack repair method of the comparative example comprises the following steps:

[0149] Step S0: The oxide layer at the crack to be repaired is removed by sandblasting and polishing.

[0150] Step S1: The filler powder and the solder powder are mechanically mixed in a ratio of 60%:40% to form a mixed powder, and then a water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of adhesive added is 7wt% of the total weight of the mixed powder and the adhesive. Then, the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and the paste mixed solder at the non-welding position outside the crack is cleaned after compaction.

[0151] Step S2: Add water-based binder (Nicrobraz s-binder produced by Wall Colmonoy Company) into the solder powder and stir evenly to form a second paste. The amount of binder added is 12wt% of the total weight of the solder powder and the binder. Then the second paste is applied to the outer surface of the first paste and the metal base material outside the original crack within a range of 2mm, and the total application amount is 2.5 times the volume of the original crack.

[0152] Step S3: Apply a flow resistance agent around the second paste, with the distance between the flow resistance agent and the second paste being 1.5mm at the farthest point.

[0153] Step S4: Place the additive manufacturing nickel-based superalloy part with the above-mentioned coating in a 110℃ oven for 1.5 hours for drying, and slightly trim the unevenly coated positions of the surface solder; then place the additive manufacturing nickel-based superalloy part in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1240℃, the holding time is 15 minutes, and after holding, argon is filled to cool to below 80℃, and the vacuum pressure in the furnace before cooling is always not higher than 4×10 - 2 Pa.

[0154] Step S5: After the crack-repaired additive manufacturing nickel-based superalloy part is taken out of the furnace, the residual solder on the outside of the original crack site is polished to the original part surface state.

[0155] As Figure 15 shown, the repaired part original crack site is checked, and it is found by visual inspection that there is a local unwelding in the original crack site, indicating that the flowability and gap filling property of the solder powder used are insufficient, and the microgap between the filler cannot be fully melted and filled, resulting in a serious lack of bonding force between the solder-filler-base material, and a visually visible unwelding defect appears.

[0156] Comparative Example 4

[0157] This comparative example provides a crack repair method for an additive manufacturing nickel-based superalloy part, wherein,

[0158] The additive manufacturing nickel-based superalloy part used in this comparative example is a part with a chemical composition of Ni-8Cr-8Co-8W-6Ta-5.5Al-0.7Ti-2Mo-0.1C-0.015B-1.4Hf printed by selective laser melting technology, and there is a through crack on the part, with a gap of 1.2mm at the widest part of the crack.

[0159] The filler powder used in the present comparative example is an alloy powder with the same chemical composition as the part, prepared by gas atomization. The gas atomization process parameters are: melting temperature 1560℃, powder spraying temperature 1540℃, atomizing gas argon, atomizing pressure 9MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of -325 mesh, which is the filler powder of the present example.

[0160] The solder powder used in the present comparative example is an alloy powder with a chemical composition of Ni-16Cr-8W-2.5B, prepared by gas atomization. The gas atomization process parameters are: melting temperature 1540℃, powder spraying temperature 1520℃, atomizing gas argon, atomizing pressure 8MPa. The alloy powder obtained by atomization is sieved to obtain an alloy powder with a particle size of -325 mesh, which is the solder powder of the present example.

[0161] The crack repair method of the present comparative example comprises the following steps:

[0162] Step S0: The oxide layer at the position to be repaired is removed by sandblasting and polishing.

[0163] Step S1: The filler powder and the solder powder are mechanically mixed in a ratio of 50:50 to form a mixed powder, and then a water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of adhesive added is 6wt% of the total weight of the mixed powder and the adhesive. Then the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and after compaction, the paste mixed solder that has overflowed outside the crack is cleaned up.

[0164] Step S2: The water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the solder powder and stirred uniformly to form a second paste. The amount of adhesive added is 12wt% of the total weight of the solder powder and the adhesive. Then the second paste is applied to the outer surface of the first paste and the metal base material within a range of 2mm outside the original crack, and the total amount of application is 3 times the volume of the original crack.

[0165] Step S3: The flow resistance agent is applied around the second paste, and the farthest distance between the flow resistance agent and the second paste is 1.6mm.

[0166] Step S4: The additive manufacturing nickel-based superalloy part with the coating as described above is placed in a 110°C oven for 1.5 hours for drying, and the unevenly coated positions of the surface layer are slightly trimmed; then the additive manufacturing nickel-based superalloy part is placed in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1230°C, the holding time is 30 minutes, and after the holding time ends, argon is filled for cooling to below 80°C. The vacuum pressure in the furnace before cooling is always not higher than 4x10 - 2 Pa.

[0167] Step S5: After the crack-repaired additive manufacturing nickel-based superalloy part is taken out of the furnace, the residual solder on the outside of the original crack site is polished to the original part surface state.

[0168] As Figure 16 shown, the original crack site of the repaired part is checked, and it is found that the linear defect is found after X-ray inspection, indicating that the compactness of the repaired site is poor, and there is a local welding defect. This is because the particle size of the filler powder is not suitable, resulting in insufficient space utilization of the mixed solder, and thus the total amount of mixed solder pressed into the crack is less, resulting in poor compactness of the weld, causing welding defects, so that the crack is not successfully repaired.

[0169] Comparative Example 5

[0170] The comparative example provides a crack repair method for an additive manufacturing nickel-based superalloy part, wherein,

[0171] The additive manufacturing nickel-based superalloy part used in the comparative example is a part with a chemical composition of Ni-8Cr-8Co-7.85W-6Ta-5.5Al-0.7Ti-2Mo-0.08C-0.015B printed by selective laser melting technology, as shown in Figure 1 and Figure 2 As shown, there is a through crack on the part, and the gap at the widest part of the crack is 1mm.

[0172] The filler powder used in the comparative example is an alloy powder with the same chemical composition as the part prepared by gas atomization method. The gas atomization process parameters are: melting temperature 1560°C, powder spraying temperature 1540°C, atomizing gas argon, atomizing pressure 9MPa. The alloy powder obtained by atomization is sieved to obtain alloy powder with particle size of (-140~+325) mesh, which is the filler powder of the present example.

[0173] The solder powder used in the present comparative example is an alloy powder with chemical composition of Ni-15Cr-7W-3B prepared by gas atomization method. The gas atomization process parameters are as follows: melting temperature is 1510°C, powder spraying temperature is 1490°C, atomizing gas is argon, and atomizing pressure is 8 MPa. The alloy powder obtained by atomization is sieved to obtain alloy powder with particle size of -325 mesh, which is the solder powder of the present example.

[0174] The crack repair method of the present comparative example comprises the following steps:

[0175] Step S0: The oxidation layer at the position to be repaired is removed by sandblasting and polishing.

[0176] Step S1: The filler powder and the solder powder are mechanically mixed at a ratio of 70:30 to form a mixed powder, and then a water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the mixed powder and stirred uniformly to form a first paste. The amount of adhesive added is 7wt% of the total weight of the mixed powder and the adhesive. Then the first paste is pressed into the original crack of the additive manufacturing nickel-based superalloy part by means of a weighing spoon, and the paste mixed solder at the non-welding position outside the crack is cleaned after compaction.

[0177] Step S2: The water-based adhesive (Nicrobraz s-binder adhesive produced by Wall Colmonoy Company) is added to the solder powder and stirred uniformly to form a second paste. The amount of adhesive added is 12wt% of the total weight of the solder powder and the adhesive. Then the second paste is applied to the outer surface of the first paste and the metal base material within 2mm outside the original crack, and the total application amount is 2.5 times the volume of the original crack.

[0178] Step S3: The flow resistance agent is applied around the second paste, and the farthest distance between the flow resistance agent and the second paste is 1.5mm.

[0179] Step S4: The additive manufacturing nickel-based superalloy part coated with the above-mentioned coating is placed in a 110°C oven for drying for 1.5 hours, and the positions where the surface solder is not uniformly coated are slightly trimmed; then the additive manufacturing nickel-based superalloy part is placed in a vacuum heat treatment furnace for crack repair treatment. The temperature of the crack repair treatment is 1160°C, the holding time is 10 minutes, and after the holding time ends, argon is filled to cool to below 80°C, and the vacuum pressure in the furnace before cooling is always not higher than 4×10 - 2 Pa.

[0180] Step S5: after the additive manufacturing nickel-based superalloy part with crack repaired is discharged, the residual solder on the outside of the original crack part is polished to the original part surface state.

[0181] As shown in Figure 17 The original crack part of the repaired part is checked, and the X-ray shows that there is a non-welding defect in the original crack part, which indicates that the ratio of the filler powder and the solder powder is not within the range of the present application, resulting in insufficient gap feeding between the solder and the filler, thereby affecting the density of the joint, and the non-welding occurs.

[0182] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. A method of crack repair of an additively manufactured nickel-based superalloy piece, characterized in that, Crack repair of an additive manufacturing nickel-based superalloy part by using filler powder and solder powder; The chemical composition of the solder powder includes, in percentage by weight: Cr 11.0-17.0wt%, W 5.0-9.0wt%, B 1-4wt%, C≤0.06wt%, Co≤0.1wt%, and Ni as the balance; The chemical composition of the filler includes, in percentage by weight: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C≤0.2wt%, B≤0.1wt%, Hf≤2wt%, and Ni as the balance; The chemical composition of the additive manufacturing nickel-based superalloy includes, in percentage by weight: Cr 6-10wt%, Co 6-10wt%, W 6-10wt%, Mo 0.5-3wt%, Al 3-6wt%, Ti 0.5-2wt%, Ta 3-6wt%, C≤0.2wt%, B≤0.1wt%, Hf≤2wt%, and Ni as the balance; The solder powder is spherical and / or near-spherical, and has a particle size of -325 mesh; and the filler powder is spherical and / or near-spherical, and has a particle size of -140+325 mesh. The crack repair method of the additive manufacturing nickel-based superalloy part includes the following steps: Step S1: pressing a first paste into a crack of the additive manufacturing nickel-based superalloy part; wherein the first paste includes filler powder, solder powder, and a binder; and the content of the binder in the first paste is not more than 8wt%; Step S2: applying a second paste to cover the first paste at the crack and at a region near the crack; wherein the second paste includes solder powder and a binder; and the content of the binder in the second paste is 8-14wt%; Step S3: applying a flow inhibitor at a position around the second paste on the additive manufacturing nickel-based superalloy part; Step S4: drying and crack repairing the additive manufacturing nickel-based superalloy part after the flow inhibitor is applied, to obtain a crack-repaired additive manufacturing superalloy part.

2. The method of crack repair of an additively manufactured nickel- based superalloy piece according to claim 1, wherein, In the solder powder: the content of B is 2-3.5wt%; and / or The chemical composition of the filler powder is the same as that of the additive manufacturing nickel-based superalloy part.

3. The method of crack repair of an additively manufactured nickel- base superalloy piece of claim 1, wherein, The preparation of the solder powder includes: carrying out gas atomization treatment on a solder alloy to obtain alloy powder; and carrying out sieving treatment on the alloy powder to select alloy powder of a set particle size as the solder powder.

4. The crack repair method of additively manufactured nickel- base superalloy pieces according to claim 3, characterized in that, The parameters of the gas atomization treatment are as follows: smelting temperature is 1390-1590℃; powder spraying temperature is 1410-1570℃; atomization gas is inert gas; and atomization pressure is 2-10MPa.

5. The method of crack repair of an additively manufactured nickel- base superalloy piece of claim 1, wherein, The preparation of the filler powder includes: carrying out gas atomization treatment on a filler alloy to obtain alloy powder; and carrying out sieving treatment on the alloy powder to select alloy powder of a set particle size as the filler powder.

6. The crack repair method of additively manufactured nickel- base superalloy pieces according to claim 5, characterized in that, The parameters of the gas atomization treatment are as follows: the smelting temperature is 1450-1620℃; the powder spraying temperature is 1440-1590℃; the atomization gas is inert gas; and the atomization pressure is 2-10MPa.

7. The crack repair method of the additive manufactured nickel-based superalloy part according to claim 1, wherein, In the first paste, the adhesive is a water-based adhesive; and / or In the first paste, the mass of the solder powder accounts for 40-50wt% of the total mass of the solder powder and the filler powder; and / or The preparation step of the first paste comprises: mixing the filler powder and the solder powder to obtain a mixed powder; Then, the adhesive is added to the mixed powder, and stirring treatment is performed to form the first paste.

8. The method of crack repair of an additively manufactured nickel- base superalloy piece of claim 1, wherein, Before the step S1, the step S0 of removing the oxide layer at the crack to be repaired on the additive manufactured nickel-based superalloy part is further included; and / or After the step S4, the step S5 of polishing the residual solder on the additive manufactured superalloy part after crack repair is further included.

9. The crack repair method of the additive manufactured nickel-based superalloy part according to claim 1, wherein, In the step S1, the first paste is pressed into the crack of the additive manufactured nickel-based superalloy part, and after compaction, the first paste on the non-welding position outside the crack is cleaned up; and / or In the step S2, the area near the crack refers to an area within 2mm from the crack; and / or In the step S2, the coating amount of the second paste is not less than 2 times the volume of the crack; and / or In the step S3, the distance between the flow resistance agent and the second paste is not more than 2mm.

10. The method of crack repair of an additively manufactured nickel- base superalloy piece of claim 1, wherein, In the step S4, The temperature of the drying treatment is 80-150℃, and the drying treatment time is 1-3 hours; and / or After the drying treatment, the surface solder on the additive manufactured nickel-based superalloy part needs to be trimmed.

11. The crack repair method of additively manufacturing a nickel- based superalloy piece according to claim 10, characterized in that, In the step S4, the crack repair treatment is performed in a vacuum heat treatment furnace or a vacuum brazing furnace.

12. The crack repair method of additively manufacturing a nickel- based superalloy piece according to claim 11, characterized in that, The temperature of the crack repair treatment is 1150-1240℃, and the holding time is 10-30 minutes.

13. The crack repair method of additively manufacturing a nickel- based superalloy piece according to claim 12, characterized in that, After the holding time ends, cooling treatment is performed by furnace cooling or argon filling.

14. The crack repair method of additively manufacturing a nickel- based superalloy piece according to claim 13, characterized in that, The vacuum pressure in the furnace is not higher than 4 x 10 -2 Pa before the cooling treatment.

15. The crack repair method of the additive manufactured nickel-based superalloy part according to any one of claims 1-14, wherein, The crack repair method of the additive manufactured nickel-based superalloy part is used to repair cracks with a crack gap size of not more than 1.2mm; and / or After the crack repair, the cracks in the additive manufactured superalloy part are eliminated, and there is no un-welded defect at the repair position.

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