A multi-component, high-alloy content nickel-based filler metal for nickel-based single crystal alloy welding

Abstract

The application provides a multi-component high-alloy-content nickel-based solder for nickel-based single crystal alloy welding, which comprises the following components and mass percentages: Co 18%-34%, Cr 18%-22%, W 4%-11%, Fe 4%-11%, Al 1%-4.0%, B 2.5%-3.2%, Si≤1.5%, Ti≤2.0%, other elements≤1.0%, and the balance of Ni. The nickel-based single crystal welding joint obtained by using the solder has no low-melting-point eutectic, is more excellent in mechanical stability, is stronger in high-temperature resistance, and is significantly improved in high-temperature strength, and the tensile strength of the joint at room temperature and 870 DEG C is above 800 MPa, reaching more than 80% of the tensile strength of the nickel-based single crystal base material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nickel-based single crystal superalloys, in particular to a multi-component high-alloy content nickel-based solder for welding nickel-based single crystal alloys, and more particularly to a solder for second-generation, third-generation and fourth-generation nickel-based single crystal alloys. BACKGROUND

[0002] Nickel-based superalloys are the preferred material for hot end components of aero-engines and gas turbines due to their good creep and fatigue properties at 80% to 90% of their melting point, as well as their corrosion resistance and excellent high-temperature microstructure stability. Nickel-based single crystals in nickel-based superalloys cause anisotropy, and in a specific orientation, in addition to the advantages of nickel-based single crystals, they raise the service temperature of hot end components to above 850°C, which is a key material for manufacturing high-thrust-ratio and high-power-to-weight-ratio engine turbine blades and guide vanes. The demand for nickel-based single crystal doublet blades manufactured by welding is also increasing, and nickel-based single crystal hollow blades manufactured by welding are one of the preferred options for single crystal hollow blades. In addition, the yield rate of nickel-based single crystal components is relatively low, less than 60%, which makes the application of nickel-based single crystal components very expensive. With the vigorous development of the aviation and energy industries, aero-engines and gas turbines are being used on a large scale, and if defective nickel-based components are discarded, a large amount of waste will be caused. At the same time, nickel-based single crystal components will also have defects such as cracks, wear and corrosion pits during use, and a large number of blades are damaged and broken every year. With the rapid development of the aerospace and energy industries, the performance requirements for hot end components are also increasing, and more and more nickel-based single crystal components are being used. However, as a result, there are more and more nickel-based single crystal components with defects and damage, and if these defective and damaged nickel-based single crystal components can be repaired and reused, not only can a large amount of resources be saved, but also the production efficiency of such components can be improved. Therefore, it is necessary to repair nickel-based single crystal components with production defects and service damage. The room temperature and high temperature performance of the joint is the first technical indicator to be considered for the manufacture of doublet blades, hollow blades and repaired components.

[0003] The TLP (Transient Liquid Phase diffusion bonding) is a diffusion bonding method. It usually uses a material with a lower melting point than the base material as an intermediate layer solder. The TLP diffusion bonding of nickel-based high-temperature alloy usually uses Si, B and P as the melting point reducing elements. When the heating temperature is higher than the melting point of the solder and lower than the melting point of the base material, the solder melts, and the melted solder fills the gap between the samples under capillary action to form a liquid film. During the holding process, the low-melting-point melting point reducing elements such as B diffuse to the two sides of the base material, and the first solidification occurs near the base material of the weld. With the extension of holding time, the solidification interface advances to the center of the weld, and the thickness of the liquid film gradually decreases until it disappears. Finally, a certain amount of compound phase is generated in the weld by the residual solute elements. Further holding, the low-melting-point elements such as B in the weld gradually homogenize. However, the existing solder combined with the TLP diffusion bonding is used for repair, and the single crystal high-temperature alloy welding part obtained has low high-temperature strength, is easy to appear low-melting-point structure, and has high requirements for the gap control precision of the weld. SUMMARY

[0004] In view of the above technical problems, the present application discloses a multi-component high-alloy content nickel-based solder for nickel-based single crystal alloy welding, which can solve the problems of low high-temperature strength, easy to appear low-melting-point structure and high requirements for the gap control precision of the weld of the single crystal high-temperature alloy welding part obtained by the existing solder. The nickel-based single crystal can be a high-temperature alloy used for aero-engine, space engine and gas turbine blade.

[0005] To this end, the technical scheme adopted by the present application is as follows:

[0006] A multi-component high-alloy content nickel-based solder for nickel-based single crystal alloy welding, the components and mass percentages thereof are as follows: Co 18wt%-34wt%, Cr 18wt%-22wt%, W 4wt%-11wt%, Fe 4wt%-11wt%, Al 1wt%-4.0wt%, B 2.5wt%-3.2wt%, Si≤1.5wt%, Ti≤2.0wt%, other elements≤1.0wt%, and the balance is Ni; the components and mass percentages of the multi-component high-alloy content nickel-based solder also satisfy the following conditions:

[0007] 1) The sum of the mass percentages of W and Fe is not less than 10wt% and not more than 18wt%;

[0008] 2) When the mass percentage of W is greater than or equal to 8wt%, the mass percentage of Ti is not more than 1.0wt%, and the mass percentage of Al is 1.0wt%;

[0009] 3) When the mass percentage content of Ni is 24wt%-38wt%, the content of Co changes with the content of Ni after the contents of Cr, W, Fe, Al, B, Si, Ti are determined.

[0010] Other elements can be one or more of C, Cu, V, Mn, Zr, Nb, Ta, Mo, Hf, Y, P, Be, or none.

[0011] Compared with the existing commercialized mature solder such as BNi-9, the content of B is reduced, so that the precipitation of B compound is reduced in the welding process; meanwhile, more alloy elements are added, and the melting point of the solder is improved. Compared with the improved solder powder disclosed in the prior art, the content of Co, Cr, W and Fe is greatly increased in the technical scheme, so that the high-temperature strength of the welded joint is further improved, and the reliability of the welded joint is improved.

[0012] As a further improvement of the present application, the components and mass percentages of the multi-component high-alloy content nickel-based solder are as follows: Co 24wt%-34wt%, Cr 20wt%-22wt%, W 6wt%-8wt%, Fe 6wt%-9wt%, Al 1wt%-2wt%, B 2.8wt%-3.0wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, and the balance is Ni.

[0013] As a further improvement of the present application, the powder particle size of the multi-component high-alloy content nickel-based solder is not more than 125μm; further preferably, the multi-component high-alloy content nickel-based solder is spherical or near-spherical.

[0014] As a further improvement of the present application, the melting point of the multi-component high-alloy content nickel-based solder is 1150-1255℃.

[0015] As a further improvement of the present application, the multi-component high-alloy content nickel-based solder is prepared into a powder solder by a vacuum argon gas atomization method, or into a thin strip solder by a vacuum spinning belt method, and the thickness of the thin strip solder is not more than 105μm. Further preferably, the thickness of the thin strip solder is not more than 80μm or less.

[0016] The present application also discloses a preparation method of the multi-component high-alloy content nickel-based solder for nickel-based single crystal alloy welding as described above, comprising:

[0017] According to the chemical component proportion, the electrode induction gas atomization powder preparation device is used to prepare the nickel-based alloy powder solder by a vacuum argon gas atomization method; or according to the chemical component proportion, the vacuum spinning belt furnace device is used to prepare the multi-component high-alloy content nickel-based thin strip solder by a vacuum spinning belt method.

[0018] The application also discloses a welding method of the nickel-based single crystal alloy, comprising the following steps:

[0019] Step S1, polishing the to-be-welded part of the alloy workpiece to be connected, cleaning the to-be-welded surface, and drying;

[0020] Step S2, mixing the multi-component high-alloy-content nickel-based solder for welding of the nickel-based single crystal alloy and the binder uniformly to obtain solder paste; coating the solder paste on the to-be-welded part of one workpiece, and then adhering the to-be-welded part of another workpiece;

[0021] Or using the thin strip solder prepared from the multi-component high-alloy-content nickel-based solder for welding of the nickel-based single crystal alloy, fixing the thin strip solder on the to-be-welded part of one workpiece, and then adhering the to-be-welded part of another workpiece;

[0022] Step S3, heating the assembled workpiece to 550-750 DEG C in an argon environment or a vacuum environment for glue removal treatment, then heating to 1000-1100 DEG C for uniform treatment, and then heating to 1240-1270 DEG C for welding treatment, keeping for 30-480 min, and cooling in the furnace.

[0023] As a further improvement of the application, in step S1, the surface of the to-be-welded part is first polished to a roughness Ra less than or equal to 1.6 by using a grinding machine, a precision lathe or sandpaper, then the to-be-welded part is cleaned to remove surface contaminants or oil stains of the to-be-welded part, and then dried.

[0024] As a further improvement of the application, in step S2, the mass ratio of the multi-component high-alloy-content nickel-based solder to the binder is 1-3:1. Further, the mass ratio of the multi-component high-alloy-content nickel-based solder to the binder is 2:1.

[0025] As a further improvement of the application, in step S2, the binder is Nicrobraz Cements 320, Nicrobraz Cements 520 or s'binder produced by the WCC company in the United States, and diluted with acetone.

[0026] As a further improvement of the application, in step S2, the thin strip solder is fixed on the to-be-welded part of one workpiece, then adhered to the to-be-welded part of another workpiece, and then a circle of solder paste is coated around the to-be-welded part, and the cross-sectional area of the solder paste is not more than 4mm 2The solder paste is obtained by uniformly mixing the multi-component high-alloy content nickel-based solder for nickel-based single crystal alloy welding and a binder.

[0027] As a further improvement of the present application, the nickel-based single crystal alloy is a second-generation nickel-based single crystal alloy, a third-generation nickel-based single crystal alloy, or a fourth-generation nickel-based single crystal alloy.

[0028] As a further improvement of the present application, in step S3, the oxygen volume percentage content of the argon environment is less than 1%, and the vacuum degree of the vacuum environment is not higher than 1*10 -2 Pa.

[0029] As a further improvement of the present application, in step S3, the temperature rising speed of the glue removal treatment is 5-20℃ / min, and the holding time is 5-60 minutes; the temperature rising speed of the uniform treatment is 5-20℃ / min; and the temperature rising speed of the welding treatment is 10-20℃ / min.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] First, the nickel-based single crystal welding joint obtained by using the multi-component high-alloy content nickel-based solder of the present application has no low-melting-point eutectic, has better mechanical stability, has stronger high-temperature resistance, has a significant improvement in high-temperature strength of the joint, and has a tensile strength of the joint at room temperature and at 870℃ of more than 800MPa, which is more than 80% of the tensile strength of the nickel-based single crystal base material, and has better stability in high-temperature environment.

[0032] Second, the multi-component high-alloy content nickel-based solder of the present application greatly increases the content of alloying elements such as Co, Cr, W, and Fe, can be welded in a wide temperature range and welding time, and has no obvious fluctuation in the performance of the joint, and the tensile strength at room temperature and high temperature can be more than 800MPa.

[0033] Third, the multi-component high-alloy content nickel-based solder of the present application reduces the content of Si or does not add Si, and can also realize high-strength welding of nickel-based single crystal, reduces or avoids the problem that a large amount of brittle compounds exist in the weld due to too high Si content, and reduces the strength of the joint. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a method for controlling the powder solder during the welding process of the first embodiment of the present application, i.e., the control is performed by using a frame structure. In the figure, the uppermost layer is a frame.

[0035] Figure 2is a schematic diagram of the microstructure of the joint obtained in Example 1 of the present application.

[0036] Figure 3 is a schematic diagram of the microstructure of the joint obtained in Example 2 of the present application.

[0037] Figure 4 is a schematic diagram of the microstructure of the joint obtained in Example 3 of the present application.

[0038] Figure 5 is a comparison chart of the joint performance obtained in Examples 1-3 of the present application.

[0039] Figure 6 is a schematic diagram of the microstructure of the joint obtained in Comparative Example 1 of the present application.

[0040] Figure 7 is a schematic diagram of the microstructure of the joint obtained in Comparative Example 2 of the present application.

[0041] Figure 8 is a schematic diagram of the microstructure of the joint obtained in Comparative Example 3 of the present application.

[0042] Figure 9 is a comparison chart of the joint performance obtained in Comparative Examples 1-3 of the present application. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present application are further described in detail below.

[0044] A multi-component high-alloy content nickel-based solder for nickel-based single crystal alloy welding, the components and mass percentages are Co 18wt%-34wt%, Cr 18wt%-22wt%, W 4wt%-11wt%, Fe 4wt%-11wt%, Al 1wt%-4.0wt%, B 2.5wt%-3.2wt%, Si≤1.5wt%, Ti≤2.0wt%, other elements≤1.0wt%, and the balance is Ni;

[0045] The ratio of the multi-component high-alloy content nickel-based solder also requires the following points:

[0046] 1) 10%≤W content (wt%) + Fe content (wt%)≤18%;

[0047] 2) When W content (wt%)≥8%, Ti content≤1.0wt%, and Al content is 1.0wt%;

[0048] 3) Ni solder is in (24wt%-38wt%), after determining the Cr, W, Fe, Al, B, Si, Ti content, adjust the Ni content by Co content.

[0049] Further, the multi-component high-alloy-content nickel-based solder has a powder particle size of not more than 125 μm, and is spherical or near-spherical; and the multi-component high-alloy-content nickel-based solder has a melting point of 1150-1255 °C.

[0050] The multi-component high-alloy-content nickel-based solder can be prepared into a powder solder by a vacuum argon gas atomization method, or into a thin strip solder by a vacuum strip casting method, and the thin strip solder has a thickness of not more than 105 μm. Specifically, the multi-component high-alloy-content nickel-based solder is prepared into a powder solder by a vacuum argon gas atomization method, or into a thin strip solder by a vacuum strip casting method.

[0051] The multi-component high-alloy-content nickel-based solder can be prepared into a powder solder by a vacuum argon gas atomization method, or into a thin strip solder by a vacuum strip casting method, and the thin strip solder has a thickness of not more than 105 μm. Specifically, the multi-component high-alloy-content nickel-based solder is prepared into a powder solder by a vacuum argon gas atomization method, or into a thin strip solder by a vacuum strip casting method.

[0052] When the multi-component high-alloy-content nickel-based solder is used for welding, the steps include:

[0053] In step S1, the welding surface of the alloy workpiece to be connected is polished to a roughness of not more than R1.6, and then the welding surface is cleaned and dried.

[0054] In step S2, the multi-component high-alloy-content nickel-based solder is mixed with a binder to obtain a solder paste, and the binder is Nicrobraz Cements 320 or 520 or s'binder produced by the WCC company in the United States, which can be diluted with acetone.

[0055] In step S3, a layer of solder paste is coated on the welding surface of one workpiece, and the thickness of the solder paste is not more than 0.3 mm, and then the welding surface of another workpiece is attached. If a thin strip solder is used, the multi-component high-alloy-content nickel-based thin strip solder for nickel-based single crystal welding according to any one of claims 1 and 3 is fixed on the welding surface of one workpiece, and then the welding surface of another workpiece is attached. In order to avoid insufficient filling, a circle of solder paste can be coated around the attached area of the welding surface, and the cross-sectional area of the solder paste is not more than 4 mm 2 .

[0056] In step S4, the assembled workpiece is placed in a heating furnace, and then argon gas is introduced as a protective gas, until the oxygen content in the heating furnace is less than 1%, or the vacuum degree is less than 1*10 -2 pa, and heating is started.

[0057] Step S5, using the way of segmented heating, heating to any temperature between 550℃-750℃ at a heating rate of 5-20℃ / min, holding for 5-60 minutes, to remove the adhesive, and then heating to any temperature between 1000℃-1100℃ at a heating rate of 5-20℃ / min, to homogenize, and then heating to any temperature between 1240-1270℃ at a heating rate of 10-20℃ / min when the workpiece temperature reaches the set temperature, holding for 30 minutes or more, within 480 minutes, and then cooling to room temperature in the furnace before taking out, and the protection gas is supplied or the vacuum state is maintained during the welding process.

[0058] The above method can be used in the welding of second, third or fourth generation nickel-based single crystal alloys.

[0059] The following will be described in detail with specific examples.

[0060] Example 1

[0061] A multi-component high-alloy content nickel-based powder solder for nickel-based single crystal superalloy welding and nickel-based superalloy component block welding repair, the component composition is as follows in mass percentage: Co 26wt%, Cr 20wt%, W 6wt%, Fe 9wt%, Al 2.0wt%, B 3wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, and the balance is Ni. The sum of the above component mass percentages is 100%.

[0062] The powder preparation method: using existing technology, using electrode induction gas atomization powder preparation device, using vacuum argon atomization method to prepare nickel-based alloy powder solder. Specifically, according to the above chemical composition ratio, first ball milling, and then smelting. Using plasma rotating electrode atomization to obtain spherical or near-spherical solder. The prepared powder solder is vacuum sieved, and the powder solder with a particle size of≤125μm is selected.

[0063] The welding experiment of the multi-component high-alloy content nickel-based powder solder of the embodiment for welding nickel-based single crystal includes the following steps:

[0064] Step S1, preparing a nickel-based single crystal superalloy welding sample: one sample size is 10mm×10mm×20mm, and the other is 10mm×14mm×20mm. The 10mm×10mm surface and the 10mm×14mm surface are welded, the sample surface is ground to a surface roughness of Ra1.6, and then the welding surface is polished with 800 mesh sandpaper to brightness, and then the welding sample is soaked in acetone for ultrasonic cleaning for 300s, and then the surface is dried with an electric hair dryer.

[0065] The experimental material described in this embodiment is DD5 nickel-based single crystal, and the composition of the material is (wt%): C: 0.05%, Cr: 7.1%, Co: 6.5%, W: 5.1%, Al: 6.2%, Ta: 6.9%, Mo: 1.5%, Hf: 0.15%, B: 0.004%, Re: 2.9%, and the balance is Ni.

[0066] Step S2, modulating the solder paste: mix the multi-component high alloy content nickel-based powder solder of this embodiment with the s'binder binder produced by WCC company according to a ratio of 2:1, then add 5 times of acetone for dilution, and obtain the solder paste.

[0067] Step S3, welding assembly: select a 100-micron-thick frame seat and place it on the surface of the workpiece to be welded in an exemplary manner, then apply the solder paste and scrape it flat with a scraper. Then, the welding surface of another workpiece to be welded is attached, the assembly of the sample is completed, and then placed in a vacuum furnace. Figure 1 Exemplary manner on the surface of the workpiece to be welded, then apply the solder paste and scrape it flat with a scraper. Then, the welding surface of another workpiece to be welded is attached, the assembly of the sample is completed, and then placed in a vacuum furnace.

[0068] Step S4, welding: before heating the sample, the vacuum furnace is evacuated, and when the vacuum degree reaches 1*10 -2 Pa, start heating, heat to 650℃ at a heating rate of 10℃ / min, keep for 30 minutes, then heat to 1050℃ uniformly at a heating rate of 10℃ / min, then continue to heat to 1260℃ at a heating rate of 15℃ / min when the temperature of the temperature measuring thermocouple on the workpiece reaches 1050℃, keep for 240 minutes, then cool to room temperature in the furnace, and take out. The vacuum furnace is always in a vacuum state during the welding process.

[0069] Example 2

[0070] A multi-component high alloy content nickel-based powder solder for nickel-based single crystal superalloy welding and nickel-based superalloy component block welding repair, the component composition is as follows in mass percentage: Co 24wt%, Cr 20wt%, W 8wt%, Fe 6wt%, Al 1.0wt%, B 3wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, and the balance is Ni. The sum of the mass percentages of the above components is 100%.

[0071] Thin strip solder preparation: using existing technology, a multi-component high alloy content nickel-based thin strip solder is prepared by vacuum tape casting. Specifically, according to the above chemical composition ratio, first ball milling is performed, and then smelting is performed. The vacuum tape casting equipment is used to prepare the strip solder, and the thickness of the solder thin strip is not higher than 105μm.

[0072] The welding process of the multi-component high-alloy content nickel-based thin strip solder for welding nickel-based single crystal in the embodiment comprises the following steps:

[0073] Step S1, preparing nickel-based single crystal high-temperature alloy welding samples: one sample has a size of 10 mm x 10 mm x 20 mm, and the other has a size of 10 mm x 14 mm x 20 mm, the 10 mm x 10 mm surface is welded with the 10 mm x 14 surface, the sample surface is ground to a surface roughness of Ra1.6, then the welding surface is polished to brightness with 800 mesh sandpaper, then the welding sample is soaked in acetone for ultrasonic cleaning for 300 s, and then the surface is blown dry with an electric hair dryer.

[0074] The experimental material described in the embodiment is DD5 nickel-based single crystal, and the composition of the material is (wt%): C: 0.05%, Cr: 7.1%, Co: 6.5%, W: 5.1%, Al: 6.2%, Ta: 6.9%, Mo: 1.5%, Hf: 0.15%, B: 0.004%, Re: 2.9%, and the balance is Ni.

[0075] Step S2, preparing the solder paste: the multi-component high-alloy content nickel-based powder solder in the embodiment is mixed with the s'binder produced by WCC company in a ratio of 2:1, then 5 times of acetone is added for dilution, and the solder paste is obtained

[0076] Step S3, welding assembly: the thin strip solder is placed between the welding surfaces of the two workpieces to be welded, then the solder paste is coated around the welding surface in the manner shown in the figure, the thickness of the coated solder paste is controlled to be 1 mm 2 , and the sample assembly is completed, and then placed in a vacuum furnace.

[0077] Step S4, welding: before heating the sample, the vacuum furnace is evacuated, and when the vacuum degree reaches 1*10 -2 Pa, heating starts, the temperature is raised to 650℃ at a rate of 10℃ / min, and the temperature is kept for 30 minutes, then the temperature is raised to 1050℃ at a rate of 10℃ / min for uniformity, then the temperature of the temperature measuring thermocouple on the workpiece reaches 1050℃, and the temperature continues to rise at a rate of 15℃ / min to 1260℃, and the temperature is kept for 150 minutes, then the furnace is cooled to room temperature, and then taken out, and the vacuum furnace is always in a vacuum state during the welding process.

[0078] Example 3

[0079] A multi-component high-alloy content nickel-based powder solder for nickel-based single crystal superalloy welding and nickel-based superalloy component block welding repair, the component composition is composed of Co 34wt%, Cr 22wt%, W 6wt%, Fe 6wt%, Al 1.0wt%, B 3wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, and the balance is Ni, and the sum of the above component mass percentages is 100%.

[0080] The powder preparation method: using the existing technology, using electrode induction gas atomization powder preparation device, using vacuum argon atomization method to prepare nickel-based alloy powder solder. Specifically, according to the above chemical composition ratio, first ball milling, and then smelting. Using plasma rotating electrode atomization powder, spherical or near spherical solder is obtained. The prepared powder solder is vacuum screened, and the powder solder with a particle size of≤125μm is selected.

[0081] The welding process of the multi-component high-alloy content nickel-based powder solder of the embodiment for welding nickel-based single crystal includes the following steps:

[0082] Step S1, preparing a nickel-based single crystal superalloy welding sample: one sample size is 10mm×10mm×20mm, and the other is 10mm×14mm×20mm, the 10mm×10mm surface and the 10mm×14mm surface are welded, the sample surface is ground to a surface roughness of Ra1.6, then 800 mesh sandpaper is used to polish the welding surface to brightness, then the welding sample is soaked in acetone for ultrasonic cleaning for 300s, and then the surface is dried with an electric hair dryer. The experimental material described in the embodiment is DD5 nickel-based single crystal, and the composition of the material is (wt%): C: 0.05%, Cr: 7.1%, Co: 6.5%, W: 5.1%, Al: 6.2%, Ta: 6.9%, Mo: 1.5%, Hf: 0.15%, B: 0.004%, Re: 2.9%, and the balance is Ni.

[0083] Step S2, preparing the solder paste: mix the multi-component high-alloy content nickel-based powder solder of the embodiment with the s'binder adhesive produced by WCC company according to a ratio of 2:1, then add 5 times of acetone for dilution, and obtain the solder paste

[0084] Step S3, welding assembly: as shown in Figure 1 , select the 100-micron-thick frame seat and place it on the surface of the workpiece to be welded, then coat the solder paste and scrape it flat with a scraper. Then, the welding surface of the other piece of the welding sample is attached, the sample assembly is completed, and then placed in a vacuum furnace.

[0085] Step S4, welding: before heating the sample, the vacuum furnace is evacuated, and when the vacuum degree reaches 1*10-2 Pa, start heating, heating to 650℃ at a heating rate of 10℃ / min, holding for 30 minutes, then heating to 1050℃ at a heating rate of 10℃ / min for homogenization, then continue heating at a heating rate of 15℃ / min to 1260℃ when the temperature of the temperature measuring thermocouple on the workpiece reaches 1050℃, holding for 90 minutes, then cooling to room temperature in the furnace, and taking out, the vacuum furnace is always in a vacuum state during the welding process.

[0086] The microstructure of the joint obtained in Examples 1-3 is shown in Figures 2-4 It can be seen that only a small amount of compound exists, meeting the use requirements.

[0087] The performance of the joint obtained in Examples 1-3 is shown in Figure 5 It can be seen that the tensile strength of the nickel-based single crystal joint obtained in Examples 1-3 at room temperature and at 870℃ is more than 800MPa, which can meet the strength requirements of the blade manufactured by welding method and the welded repair.

[0088] Comparative Example 1

[0089] A multi-component high-alloy content nickel-based powder solder for welding of nickel-based single crystal superalloys and welding repair of nickel-based superalloy component blocks, the component composition is as follows in mass percentage: Co: 38wt%, Cr: 22wt%, W: 9wt%, Fe: 6wt%, Al: 1.0wt%, B: 3wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, the balance is Ni, the sum of the above component mass percentages is 100%. The Co content exceeds the design range.

[0090] Powder preparation method: according to the above chemical composition ratio, first ball milling, then melting. Using plasma rotating electrode atomization to prepare powder, spherical or near-spherical solder is obtained. The prepared powder solder is vacuum sieved, and the powder solder with a particle size of ≤125μm is selected.

[0091] The welding process of the multi-component high-alloy content nickel-based powder solder of the present embodiment for welding of nickel-based single crystal includes the following steps:

[0092] Step S1, preparing nickel-based single crystal superalloy welding sample: one sample size is 10mmx10mmx20mm, and the other is 10mmx14mmx20mm, the 10mmx10mm surface and the 10mmx14mm surface are welded, the sample surface is ground to Ra1.6 using a grinding machine, then the welding surface is polished to bright using 800 mesh sandpaper, then the welding sample is immersed in acetone for ultrasonic cleaning for 300s, and then the surface is dried using an electric hair dryer. The experimental material described in this embodiment is DD5 nickel-based single crystal, and the composition of the material is (%wt): C: 0.05%, Cr: 7.1%, Co: 6.5%, W: 5.1%, Al: 6.2%, Ta: 6.9%, Mo: 1.5%, Hf: 0.15%, B: 0.004%, Re: 2.9%, and the balance is Ni.

[0093] Step S2, preparing solder paste: mix the multi-component high alloy content nickel-based powder solder of this embodiment with the s'binder produced by WCC company according to a ratio of 2:1, then add 5 times of acetone for dilution to obtain the solder paste

[0094] Step S3, welding assembly: select a 100-micron-thick frame seat and place it on the surface of the workpiece to be welded in an exemplary manner, then apply the solder paste and flatten it with a scraper. Then, the welding surface of the other workpiece to be welded is attached, the assembly is completed, and then placed in a vacuum furnace. Figure 1

[0095] Step S4, welding: before heating the sample, the vacuum furnace is evacuated, and when the vacuum degree reaches below 1*10-2pa, heating begins. The temperature is raised to 650℃ at a rate of 10℃ / min, and the temperature is kept for 30 minutes. Then, the temperature is raised to 1050℃ uniformly at a rate of 10℃ / min. When the temperature of the temperature measuring thermocouple on the workpiece reaches 1050℃, the temperature continues to rise at a rate of 15℃ / min to 1260℃, and the temperature is kept for 90 minutes. After that, the workpiece is cooled to room temperature in the furnace, and then taken out. During the welding process, the vacuum furnace is always in a state of vacuum.

[0096] Comparative Example 2

[0097] A multi-component high alloy content nickel-based powder solder for nickel-based single crystal superalloy welding and nickel-based superalloy component block welding repair, the component composition is as follows in mass percentage: Co: 32wt%, Cr: 22wt%, W: 9wt%, Fe: 6wt%, Al: 1.0wt%, B: 3wt%, Si≤0.1wt%, Ti=3.0wt%, other elements≤1.0wt%, and the balance is Ni. The sum of the mass percentages of the above components is 100%. The Ti content exceeds the design range.

[0098] ​The powder preparation method is as follows: ingredients are prepared according to the above chemical composition ratio, first ball milling, and then melting. The powder is obtained by plasma rotating electrode atomization, and the powder is spherical or near-spherical. The prepared powder solder is vacuum sieved, and the powder solder with a particle size of ≤125 μm is selected.

[0099] The welding process of the multi-component high-alloy content nickel-based powder solder for welding nickel-based single crystal in the embodiment includes the following steps:

[0100] Step S1, preparing nickel-based single crystal high-temperature alloy welding samples: one sample is 10mmx10mmx20mm in size, and the other is 10mmx14mmx20mm. The 10mmx10mm surface is welded to the 10mmx14mm surface. The surface of the sample is ground to a surface roughness of Ra1.6, and then polished with 800 mesh sandpaper. Then, the welding sample is immersed in acetone for ultrasonic cleaning for 300s, and then dried with an electric hair dryer. The experimental material in the embodiment is DD5 nickel-based single crystal, and the composition of the material is (wt%): C: 0.05%, Cr: 7.1%, Co: 6.5%, W: 5.1%, Al: 6.2%, Ta: 6.9%, Mo: 1.5%, Hf: 0.15%, B: 0.004%, Re: 2.9%, and the balance is Ni.

[0101] Step S2, preparing the solder paste: the multi-component high-alloy content nickel-based powder solder in the embodiment is mixed with the s'binder produced by WCC company in a ratio of 2:1, and then 5 times of acetone is added for dilution to obtain the solder paste

[0102] Step S3, welding assembly: a 100-micron-thick frame seat is placed on the surface of the workpiece to be welded in the form of an example, then the solder paste is coated, and the scraper is used to flatten it. Then, the welding surface of the other workpiece to be welded is attached, the sample assembly is completed, and then placed in a vacuum furnace. Figure 1

[0103] Step S4, welding: before heating the sample, the vacuum furnace is evacuated, and when the vacuum degree reaches 1*10-2pa or less, heating begins. The temperature is raised to 650℃ at a rate of 10℃ / min, and the temperature is kept for 30 minutes. Then, the temperature is raised to 1050℃ uniformly at a rate of 10℃ / min, and then the temperature of the thermocouple on the workpiece reaches 1050℃. Continue to heat at a rate of 15℃ / min to 1260℃, and keep the temperature for 90 minutes. After that, the furnace is cooled to room temperature and taken out. The vacuum furnace is always in a vacuum state during the welding process.

[0104] Comparative Example 3

[0105] ​A multi-component high-alloy content nickel-based powder solder for nickel-based single crystal superalloy welding and nickel-based superalloy component block welding repair, the component composition is composed of Co: 32wt%, Cr: 22wt%, W: 9wt%, Fe: 10wt%, Al: 1.0wt%, B: 3wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, and the balance is Ni, the sum of the above component mass percentages is 100%. The sum of W and Fe content exceeds the design range.

[0106] The powder preparation method is as follows: according to the above chemical composition ratio, first ball milling, then smelting. Using plasma rotating electrode atomization process, spherical or near-spherical solder is obtained. The prepared powder solder is vacuum sieved, and the powder solder with particle size ≤125μm is selected.

[0107] The welding process of the multi-component high-alloy content nickel-based powder solder of the embodiment for welding nickel-based single crystal includes the following steps:

[0108] Step S1, preparing nickel-based single crystal superalloy welding sample: one sample size is 10mmx10mmx20mm, and the other is 10mmx14mmx20mm, the 10mmx10mm surface is welded with the 10mmx14mm surface, the sample surface is ground to Ra1.6 using a grinding machine, then the welding surface is polished with 800 mesh sandpaper to brightness, then the welding sample is soaked in acetone for ultrasonic cleaning for 300s, and then the surface is dried with electric hair dryer. The experimental material of the embodiment is DD5 nickel-based single crystal, and the composition of the material is (wt%): C: 0.05%, Cr: 7.1%, Co: 6.5%, W: 5.1%, Al: 6.2%, Ta: 6.9%, Mo: 1.5%, Hf: 0.15%, B: 0.004%, Re: 2.9%, and the balance is Ni.

[0109] Step S2, preparing solder paste: mix the multi-component high-alloy content nickel-based powder solder of the embodiment with s'binder produced by WCC company according to the ratio of 2:1, then add 5 times of acetone for dilution, and obtain the solder paste

[0110] Step S3, welding assembly: select a 100-micron-thick frame seat and place it on the surface of the workpiece to be welded in the form of an example, then coat the solder paste and scrape it flat with a scraper. Then, the welding surface of the other workpiece to be welded is attached, the sample assembly is completed, and then placed in a vacuum furnace. Figure 1

[0111] ​Step S4, welding: before the sample is heated, the vacuum furnace is vacuumized, and when the vacuum degree reaches below 1*10-2 Pa, heating is started, and heating is performed at a temperature increasing rate of 10℃ / min to 650℃, and then uniform heating is performed at a temperature increasing rate of 10℃ / min to 1050℃, and then when the temperature of the temperature measuring thermocouple on the workpiece reaches 1050℃, the temperature is continuously increased, and heating is continuously performed at a temperature increasing rate of 15℃ / min to 1260℃, and the temperature is kept for 90 minutes, and then the workpiece is taken out after the furnace is cooled to room temperature, and the vacuum furnace is always in a vacuum state during the welding process.

[0112] The microstructure of the nickel-based single crystal joint obtained in Comparative Examples 1-3 is shown in the enlarged view of Figures 6-8 It can be seen that a large number of micro-holes appear in the brazing seam. The performance of the nickel-based single crystal joint obtained in Comparative Examples 1-3 is shown in Table 2. Figure 9 It can be seen that the tensile strength at room temperature and at 870℃ is lower than 750MPa, which cannot meet the strength of the blade manufactured by the welding method and the welded repair.

[0113] On the basis of Example 1, the proportion of alloy elements is adjusted, and the performance of the multi-component high-alloy content nickel-based powder solder prepared by the process of Example 1 is tested, as shown in Table 1. The comparison is shown in Table 2. It can be seen that the joint obtained after the nickel-based single crystal high-temperature alloy is welded by using the multi-component high-alloy content nickel-based powder solder of the technical scheme of the application has a tensile strength at room temperature and at 870℃ of greater than 800MPa.

[0114] Table 1: Performance table of different proportions of examples

[0115]

[0116] Table 2: Performance table of different proportions of comparative examples

[0117]

[0118] The above is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present application, and all of them should be regarded as falling within the protection scope of the present application.

Claims

1. A multi-component, high-alloy content nickel-based filler for nickel-based single crystal alloy welding, characterized in that, The components and mass percentages thereof are: Co 18wt%-34wt%, Cr 18wt%-22wt%, W 4wt%-11wt%, Fe 4wt%-11wt%, Al 1wt%-4.0wt%, B 2.5wt%-3.2wt%, Si≤1.5wt%, Ti≤2.0wt%, other elements≤1.0wt%, and the balance is Ni; the components and mass percentages of the multi-component high-alloy-content nickel-based solder further satisfy the following conditions: 1) the sum of the mass percentages of W and Fe is not less than 10wt% and not more than 18wt%; 2) when the mass percentage of W is greater than or equal to 8wt%, the mass percentage of Ti is not more than 1.0wt%, and the mass percentage of Al is 1.0wt%; 3) when the mass percentage of Ni is 24wt%-38wt%, the content of Co changes with the content of Ni after the contents of Cr, W, Fe, Al, B, Si, and Ti are determined.

2. The multi-component, high-alloy content nickel-based filler for nickel-based single crystal alloy welding of claim 1, wherein: The components and mass percentages of the multi-component high-alloy-content nickel-based solder are: Co 24wt%-34wt%, Cr 20wt%-22wt%, W 6wt%-8wt%, Fe 6wt%-9wt%, Al 1wt%-2wt%, B 2.8wt%-3.0wt%, Si≤0.1wt%, Ti≤0.1wt%, other elements≤1.0wt%, and the balance is Ni.

3. The multi-component, high alloy content nickel-based filler for nickel-based single crystal alloy welding of claim 2, wherein: The powder particle size of the multi-component high-alloy-content nickel-based solder is not more than 125μm, and the powder is spherical or near-spherical; the melting point of the multi-component high-alloy-content nickel-based solder is 1150-1255℃.

4. The multi-component, high alloy content nickel-based filler for nickel-based single crystal alloy welding of claim 3, wherein: The powder solder is prepared by a vacuum argon gas atomization method, or the thin strip solder is prepared by a vacuum strip casting method, and the thickness of the thin strip solder is not more than 105μm.

5. The preparation method of the multi-component high-alloy-content nickel-based solder for nickel-based single crystal alloy welding according to claim 4, characterized in that: ingredients are prepared according to the chemical composition ratio, a nickel-based alloy powder solder is prepared by a vacuum argon gas atomization method by using an electrode induction gas atomization powder preparation device; or ingredients are prepared according to the chemical composition ratio, a multi-component high-alloy-content nickel-based thin strip solder is prepared by a vacuum strip casting method by using a vacuum strip casting furnace device.

6. A method of welding a nickel-based single crystal alloy, characterized by: and comprises the following steps: Step S1, polishing the to-be-welded part of the alloy workpiece to be connected, cleaning the to-be-welded surface, and drying; Step S2, mixing the multi-component high-alloy-content nickel-based solder for nickel-based single crystal alloy welding according to any one of claims 1-4 with a binder to obtain a solder paste; coating a layer of the solder paste on the to-be-welded part of one workpiece, and the thickness is not more than 0.3mm, and then bonding with the to-be-welded part of another workpiece; or using the multi-component high-alloy-content nickel-based solder for nickel-based single crystal alloy welding according to any one of claims 1-4 to prepare a thin strip solder, fixing the thin strip solder on the to-be-welded part of one workpiece, and then bonding with the to-be-welded part of another workpiece; Step S3, the assembled workpiece to be welded is first heated to 550-750 DEG C in an argon environment or vacuum environment for glue removal treatment, then heated to 1000-1100 DEG C for uniform treatment, and then heated to 1240-1270 DEG C for welding treatment, with heat preservation for 30-480 minutes, and cooled in the furnace.

7. The method of welding a nickel-base single crystal alloy of claim 6, wherein: In step S2, the binder is Nicrobraz Cements 320, Nicrobraz Cements 520 or s'binder binder, and diluted with acetone. In step S2, the thin ribbon solder is fixed to the to-be-soldered part of one workpiece, and then is attached to the to-be-soldered part of another workpiece. Then, a circle of solder paste is coated around the to-be-soldered part, and the cross-sectional area of the solder paste is not more than 4mm 2 .

8. The method of welding a nickel-base single crystal alloy of claim 6, wherein: The nickel-based single crystal alloy is a second-generation nickel-based single crystal alloy, a third-generation nickel-based single crystal alloy or a fourth-generation nickel-based single crystal alloy.

9. The method of welding a nickel-base single crystal alloy of claim 6, wherein: In step S3, the oxygen volume percentage content of the argon environment is less than 1%, and the vacuum degree of the vacuum environment is not higher than 1*10 -2 Pa.

10. The method of welding a nickel-base single crystal alloy of claim 6, wherein: In step S3, the heating rate of the glue removal treatment is 5-20 DEG C / min, and the heat preservation time is 5-60 minutes; the heating rate of the uniform treatment is 5-20 DEG C / min; and the heating rate of the welding treatment is 10-20 DEG C / min.

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