Method for connecting titanium-aluminum series material and nickel-based superalloy and brazing filler metal composition

Abstract

The invention provides a method for connecting a titanium-aluminum material and a nickel-based superalloy and a brazing filler metal composition, and relates to the technical field of material welding, and the brazing filler metal composition for connecting the titanium-aluminum material and the nickel-based superalloy comprises a high-entropy alloy middle layer and a Cu middle layer. The Cu intermediate layer is introduced between the high-entropy alloy intermediate layer and the base metal nickel-based superalloy, the low melting point of the Cu intermediate layer is utilized, the Cu intermediate layer is melted into a liquid phase in the welding process, a high-temperature liquid phase environment is formed, element diffusion of the high-entropy alloy intermediate layer and the nickel-based superalloy is facilitated, element exchange between the high-entropy alloy intermediate layer and the nickel-based superalloy is promoted, and the welding quality is improved. And the welding temperature is reduced by 30-100 DEG C, the welding temperature is reduced to 1100-1160 DEG C, the welding temperature is lower than the Ni-based high-temperature alloy solution treatment temperature, Ni-based high-temperature alloy grain growth is avoided, the high-temperature creep property of the Ni-based high-temperature alloy grain growth is kept, the joint structure is optimized, and the welding quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of material welding, and in particular to a method for connecting a titanium-aluminum material and a nickel-based high-temperature alloy and a solder composition. Background Art

[0002] For a long time, Ni-based high-temperature alloys have been widely used in aircraft engines due to their excellent corrosion resistance, oxidation resistance, and good high-temperature performance. Ni-based high-temperature alloys are high-temperature alloys with Ni as the matrix, which have high strength and good oxidation and corrosion resistance in the range of 650°C to 1000°C. Due to their good comprehensive mechanical properties, a large number of Ni-based high-temperature alloys are used in aircraft. The hot end parts of the engine, such as guide blades, turbine blades, turbine disks, and combustion chambers, are almost all made of Ni-based high-temperature alloys. However, with the continuous advancement of technology, the density exceeds 8.0 g / cm 3 The Ni-based high-temperature alloy limits the further improvement of engine performance.

[0003] TiAl-based materials are highly promising lightweight, high-temperature-resistant structural materials. Their low density, high specific strength, and excellent high-temperature performance make them one of the most promising candidates for next-generation aircraft engine hot-end components. However, the inherent brittleness of intermetallic compounds limits their application in complex structures. Therefore, research is imperative to connect TiAl-based materials with Ni-based superalloys, combining their strengths to create lightweight, high-strength, and high-temperature-resistant integrated components.

[0004] However, TiAl-based materials and Ni-based superalloys differ significantly in their physical and chemical properties, making their joints a highly dissimilar combination. The two materials differ significantly in composition, and the element Ti has a strong affinity with both Ni and Al, leading to a strong reaction between the three, forming brittle Al-Ni-Ti intermetallic compounds. Excessive amounts of these compounds can degrade the mechanical properties of the joint.

[0005] Current research on joining TiAl-based materials to Ni-based superalloys primarily involves fusion welding, diffusion welding, and brazing. Due to the inherent brittleness of TiAl-based materials, conventional fusion welding is not conducive to achieving good weld joints. Diffusion welding and brazing are considered more effective methods for joining TiAl-based materials to Ni-based superalloys. Compared to diffusion welding, brazing is more suitable for joining components with complex shapes and offers a simpler process.

[0006] Ag-Cu, Ni-based, and Ti-based filler metals are commonly used for brazing TiAl-based materials and Ni-based superalloys. The high-temperature performance of joints obtained using Ag-Cu filler metals is insufficient, while Ni-based and Ti-based filler metals easily react with the base metal to form a large, brittle Ti-Ni-Al compound layer, which significantly negatively impacts the mechanical properties of the joint. Consequently, the strength of brazed joints between TiAl-based materials and Ni-based superalloys is currently poor. Summary of the Invention

[0007] The problem solved by the present invention is how to solve the problem of poor strength of the brazing joint between TiAl-based materials and Ni-based high-temperature alloys.

[0008] In order to solve the above problems, the present invention provides a method for connecting titanium-aluminum materials and nickel-based high-temperature alloys and a brazing material composition.

[0009] In the first aspect, the present invention provides a solder composition for connecting titanium-aluminum materials and nickel-based high-temperature alloys, comprising a high-entropy alloy intermediate layer and a Cu intermediate layer arranged in sequence, wherein the side of the high-entropy alloy intermediate layer away from the Cu intermediate layer is used to connect the titanium-aluminum materials, and the side of the Cu intermediate layer away from the high-entropy alloy intermediate layer is used to connect the nickel-based high-temperature alloy.

[0010] Optionally, the high entropy alloy intermediate layer includes Ni, Cr, Fe, Zr, Hf, Cu and Sn.

[0011] Optionally, the high entropy alloy intermediate layer includes, by atomic percentage, 20% to 30% Ni, 3% to 8% Cr, 2% to 7% Fe, 20% to 30% Zr, 5% to 15% Hf, 5% to 15% Cu and 15% to 25% Sn.

[0012] Optionally, the titanium-aluminum series materials include all alloys, intermetallic compounds, ceramics and composite materials based on Ti and Al.

[0013] Optionally, the thickness ratio of the high entropy alloy intermediate layer to the Cu intermediate layer is less than 5.

[0014] In a second aspect, the present invention provides a method for connecting a titanium-aluminum material and a nickel-based high-temperature alloy, using the brazing filler metal composition for connecting a titanium-aluminum material and a nickel-based high-temperature alloy as described in any one of the above items, comprising the following steps: Arranging the titanium-aluminum material, the brazing material composition, and the nickel-based high-temperature alloy in sequence so that the titanium-aluminum material, the high-entropy alloy intermediate layer of the brazing material composition, the Cu intermediate layer of the brazing material composition, and the nickel-based high-temperature alloy are in contact with each other; When the temperature rises to 1100 to 1150°C, the Cu intermediate layer melts to form a liquid phase, forming a uniform weld.

[0015] Optionally, the heating step is performed under a vacuum environment.

[0016] Optionally, after the steps of sequentially arranging the titanium-aluminum material, the solder composition and the nickel-based high-temperature alloy, a pressure of 0.1 to 0.5 MPa is applied to bring the titanium-aluminum material, the high-entropy alloy intermediate layer of the solder composition, the Cu intermediate layer of the solder composition and the nickel-based high-temperature alloy into contact.

[0017] Optionally, in the step of increasing the temperature to 1100 to 1150° C., the temperature is increased at a rate of 5 to 20° C. / min.

[0018] Optionally, after the step of raising the temperature to 1100 to 1150° C., the temperature is maintained for 5 to 30 minutes.

[0019] The beneficial effects of the connection method and solder composition of the titanium-aluminum material and nickel-based high-temperature alloy of the present invention are as follows: a Cu intermediate layer is introduced between the high-entropy alloy intermediate layer and the base material nickel-based high-temperature alloy, the melting point of the Cu intermediate layer is 1083°C, and the low melting point of the Cu intermediate layer is utilized. During the welding process, the Cu intermediate layer melts into a liquid phase to form a high-temperature liquid phase environment, which is conducive to the element diffusion of the high-entropy alloy intermediate layer and the nickel-based high-temperature alloy, promotes the element exchange between the high-entropy alloy intermediate layer and the nickel-based high-temperature alloy, and accelerates the formation of the joint, thereby reducing the welding temperature by 30 to 100°C, and reducing the welding temperature to 1100-1160°C, so that the welding temperature is lower than the solution treatment temperature of the Ni-based high-temperature alloy, avoiding the growth of the Ni-based high-temperature alloy grains, maintaining its high-temperature creep performance, optimizing the joint structure, and improving the welding quality. At the same time, the Cu element volatilizes in the vacuum environment of the welding process and does not remain in the joint, ensuring the high-temperature performance of the joint. The introduction of a Cu interlayer does not adversely affect the high-entropy effect and delayed diffusion effect of the high-entropy alloy interlayer. The high-entropy alloy interlayer still reduces the formation of brittle phases, creates a high-density dislocation in the weld region, and simultaneously forms a high-entropy solid solution structure, improving the joint's strength, toughness, and oxidation resistance. The introduction of a Cu interlayer between the high-entropy alloy interlayer and the parent nickel-based superalloy gives the TiAl / Ni-based superalloy joint excellent mechanical properties, with a shear strength of nearly 500 MPa at room temperature, exceeding 490 MPa at 650°C, and maintaining a shear strength above 490 MPa after being held at 900°C for 500 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the arrangement of the titanium-aluminum material, the high-entropy alloy intermediate layer, the Cu intermediate layer, and the nickel-based high-temperature alloy for connecting the titanium-aluminum material and the nickel-based high-temperature alloy according to an embodiment of the present invention; Figure 2 This is a scanning electron microscope image of the Ti3AlC2 ceramic / GH3536 joint of Example 1; Figure 3This is a scanning electron microscope image of the Ti3AlC2 ceramic / GH3039 joint of Example 2; Figure 4 This is a scanning electron microscope image of the TiAl-based composite material / GH3536 joint of Example 3; Figure 5 This is a scanning electron microscope image of the TiAl alloy / GH3039 joint of Example 4; Description of reference numerals: 1. Titanium-aluminum materials; 2. High-entropy alloy intermediate layer; 3. Cu intermediate layer; 4. Nickel-based high-temperature alloy. DETAILED DESCRIPTION

[0021] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0022] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the present invention description are only for the purpose of describing specific embodiments and are not intended to limit the present invention; As used herein, the term "including" and its variations are open-ended, i.e., "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments." Definitions of other terms are provided in the following description.

[0023] In related technologies, a high-entropy alloy (HEA) interlayer forms a stable HEA at the TiAl / Ni-based superalloy joint interface through a solid-solution strengthening mechanism involving multiple primary alloying elements, improving weld strength and service performance. However, HEA interlayers typically have a high melting point, and welding temperatures (>1200°C) are high, leading to grain growth in the Ni-based superalloy, which in turn reduces high-temperature creep performance and compromises joint quality.

[0024] In response to the problems existing in the above-mentioned related technologies, embodiments of the present invention provide a method for connecting a titanium-aluminum material and a nickel-based high-temperature alloy and a brazing filler metal composition.

[0025] like Figure 1 As shown, an embodiment of the present invention provides a solder composition for connecting titanium-aluminum materials and nickel-based high-temperature alloys, comprising a high-entropy alloy intermediate layer 2 and a Cu intermediate layer 3 arranged in sequence, wherein the side of the high-entropy alloy intermediate layer 2 away from the Cu intermediate layer 3 is used to connect the titanium-aluminum material 1, and the side of the Cu intermediate layer 3 away from the high-entropy alloy intermediate layer 2 is used to connect the nickel-based high-temperature alloy 4.

[0026] In this embodiment, a Cu intermediate layer 3 is introduced between the high-entropy alloy intermediate layer 2 and the parent nickel-based high-temperature alloy 4. The melting point of the Cu intermediate layer 3 is 1083°C. Utilizing the low melting point of the Cu intermediate layer 3, the Cu intermediate layer 3 melts into a liquid phase during the welding process, forming a high-temperature liquid phase environment, which is conducive to the element diffusion of the high-entropy alloy intermediate layer 2 and the nickel-based high-temperature alloy 4, promotes the element exchange between the high-entropy alloy intermediate layer 2 and the nickel-based high-temperature alloy 4, and accelerates the formation of the joint, thereby reducing the welding temperature by 30 to 100°C, and reducing the welding temperature to 1100-1160°C, so that the welding temperature is lower than the solution treatment temperature of the Ni-based high-temperature alloy, avoiding the growth of the Ni-based high-temperature alloy grains, maintaining its high-temperature creep properties, optimizing the joint organization, and improving the welding quality. At the same time, the Cu element volatilizes in the vacuum environment of the welding process and does not remain in the joint, ensuring the high-temperature performance of the joint. The introduction of the Cu interlayer 3 does not adversely affect the high-entropy effect and delayed diffusion effect of the high-entropy alloy interlayer 2. The high-entropy alloy interlayer 2 still reduces the formation of brittle phases, forms a high-density dislocation in the weld region, and simultaneously forms a high-entropy solid solution structure, improving the joint's toughness and oxidation resistance. The introduction of the Cu interlayer 3 between the high-entropy alloy interlayer 2 and the parent nickel-based superalloy 4 imparts excellent mechanical properties to the TiAl-based material / Ni-based superalloy joint, with a room-temperature shear strength of nearly 500 MPa, a shear strength exceeding 490 MPa at 650°C, and a shear strength exceeding 490 MPa even after being held at 900°C for 500 hours.

[0027] Specifically, titanium-aluminum materials (Ti-Al materials) cover all alloys, intermetallic compounds, ceramics and their composite materials based on Ti and Al.

[0028] Optionally, the thickness ratio of the high entropy alloy intermediate layer 2 to the Cu intermediate layer 3 is less than 5.

[0029] In this optional embodiment, specifically, the thickness of the high entropy alloy intermediate layer 2 does not exceed 300 μm, and the thickness of the Cu intermediate layer 3 is 10 to 100 μm. Cu is an electronegative element, and copper has a relatively high positive mixing enthalpy. It tends to form weak bonds with other metal elements in the alloy, making it easy for it to segregate and precipitate in the interdendritic region, forming Cu aggregates. The vapor pressure of Cu increases significantly with increasing temperature. In high vacuum (e.g., <10 -4Pa) environment, the external pressure is low, and the escape of Cu atoms is more likely to occur. At about 1100 ° C, the saturated vapor pressure of Cu has reached ~10 -3 Pa significantly volatilizes in a vacuum. Furthermore, due to the lack of oxygen in a vacuum, a dense oxide film (such as Cu2O or CuO) cannot form on the copper surface to inhibit volatilization. The thickness of the Cu intermediate layer 3 is 10 to 100 μm, allowing it to volatilize almost completely, ensuring the joint is free of low-melting-point phases and improving the joint's high-temperature resistance. The thickness ratio of the high-entropy alloy intermediate layer 2 to the Cu intermediate layer 3 is less than 5, and the thickness of the high-entropy alloy intermediate layer 2 does not exceed 300 μm. This ensures that the high-entropy alloy intermediate layer 2 fully melts, improving joint strength. Excessively thick high-entropy alloy intermediate layer 2 will not fully melt, resulting in reduced joint strength.

[0030] Optionally, the high entropy alloy intermediate layer 2 includes Ni, Cr, Fe, Zr, Hf, Cu and Sn.

[0031] In this optional embodiment, the high-entropy alloy intermediate layer 2 includes Ni, Cr, Fe, Zr, Hf, Cu, and Sn. Through the solid solution strengthening mechanism of multiple major alloying elements, a stable high-entropy solid solution can be formed at the interface of the TiAl-based material / Ni-based superalloy joint, thereby improving weld strength and service performance. A Cu intermediate layer 3 is introduced between the high-entropy alloy intermediate layer 2 and the parent Ni-based superalloy. The low melting point of Cu (1083°C) is utilized to form a high-temperature liquid phase environment during the welding process. After melting, the Cu intermediate layer 3 promotes the diffusion of elements such as Ni and Cr, allowing the high-entropy alloy intermediate layer 2 to react more quickly with the parent Ni-based superalloy, accelerating joint formation, lowering the brazing temperature, preventing grain growth of the Ni-based superalloy, reducing damage to the parent material, and ensuring high-temperature creep performance. At the same time, the Cu element and the Cu and Sn elements in the high-entropy alloy intermediate layer 2 volatilize in a vacuum environment, ensuring that the final joint performance is not affected by the low-melting-point elements and improving high-temperature resistance.

[0032] The introduction of Cu intermediate layer 3 does not adversely affect the high-entropy effect and hysteretic diffusion effect of high-entropy alloy intermediate layer 2. High-entropy alloy intermediate layer 2 can still optimize the joint interface structure, avoid excessive formation of brittle phases, and generate a dispersed face-centered cubic Ti-based solid solution and high-entropy solid solution in the joint, thereby improving the joint strength and durability.

[0033] Specifically, the Cu in the high-entropy alloy intermediate layer 2 is dissolved in the Zr-Ni compound, which has a melting point exceeding 1150°C. Although this can lower the melting point of the solder, its effect is limited. During welding, after the solder of the high-entropy alloy intermediate layer 2 is completely melted, the Cu in the high-entropy alloy intermediate layer 2 is replaced in the interdendritic region due to the difference in electronegativity, forming Cu aggregates. Cu has a high saturated vapor pressure and evaporates in a high vacuum environment. However, the separate Cu intermediate layer 3 melts at 1083°C, forming a high-temperature liquid phase environment, which promotes the accelerated melting and diffusion of the high-entropy intermediate layer, which has not yet melted, thereby reducing the welding temperature and accelerating joint formation.

[0034] Optionally, the high entropy alloy intermediate layer 2 includes, by atomic percentage, 20% to 30% Ni, 3% to 8% Cr, 2% to 7% Fe, 20% to 30% Zr, 5% to 15% Hf, 5% to 15% Cu, and 15% to 25% Sn.

[0035] Optionally, the titanium-aluminum material 1 covers all alloys, intermetallic compounds, ceramics and composite materials based on Ti and Al, such as TiAl-based alloys or Ti3AlC2 ceramics.

[0036] In this optional embodiment, TiAl-based alloys are highly promising lightweight, high-temperature-resistant structural materials. Their low density, high specific strength, and excellent high-temperature performance make them one of the most promising candidates for next-generation aircraft engine hot-end components. However, the inherent brittleness of TiAl intermetallic compounds limits their application in complex structures. Therefore, joining TiAl-based materials with Ni-based high-temperature alloys combines the advantages of these two materials to form a lightweight, high-strength, and high-temperature-resistant integrated component.

[0037] Specifically, the titanium-aluminum material 1 can also be a TiAl-based composite material. The TiAl-based composite material is a high-performance lightweight structural material that uses γ-TiAl (titanium-aluminum intermetallic compound) as a matrix and introduces a reinforcing phase (such as ceramic particles, fibers or metal phase) or a second phase to modify its properties to improve its high-temperature strength, toughness, oxidation resistance and creep resistance. Commonly used reinforcing phases are (1) ceramic particles such as TiC, TiB2, SiC, Al2O3, NbC, B4C, and MAX phases, and (2) short fibers / whiskers, such as SiC whiskers and Al2O3 fibers.

[0038] Another embodiment of the present invention provides a method for connecting a titanium-aluminum material and a nickel-based high-temperature alloy, using the brazing filler metal composition for connecting a titanium-aluminum material and a nickel-based high-temperature alloy as described in any one of the above items, comprising the following steps: Arrange the titanium-aluminum material 1, the brazing material composition, and the nickel-based superalloy 4 in sequence, so that the titanium-aluminum material 1, the high-entropy alloy intermediate layer 2 of the brazing material composition, the Cu intermediate layer 3 of the brazing material composition, and the nickel-based superalloy 4 are in contact; The temperature is raised to 1100 to 1150°C and kept at this temperature for 5 to 30 minutes, and the Cu intermediate layer 3 melts to form a liquid phase, thereby forming a uniform weld.

[0039] In this embodiment, a Cu intermediate layer 3 is introduced between the high-entropy alloy intermediate layer 2 and the parent nickel-based high-temperature alloy 4. The melting point of the Cu intermediate layer 3 is 1083°C. Utilizing the low melting point of the Cu intermediate layer 3, the Cu intermediate layer 3 melts into a liquid phase during the welding process, forming a high-temperature liquid phase environment, which is conducive to the element diffusion of the high-entropy alloy intermediate layer 2 and the nickel-based high-temperature alloy 4, promotes the element exchange between the high-entropy alloy intermediate layer 2 and the nickel-based high-temperature alloy 4, and accelerates the formation of the joint, thereby reducing the welding temperature by 30 to 100°C, reducing the welding temperature to 1100-1150°C, and keeping at 1100 to 1150°C for 5 to 30 minutes, so that the welding temperature is lower than the solution treatment temperature of the Ni-based high-temperature alloy, avoiding the growth of the Ni-based high-temperature alloy grains, maintaining its high-temperature creep properties, optimizing the joint organization, and improving the welding quality. The introduction of the Cu intermediate layer 3 does not adversely affect the high entropy effect, hysteresis diffusion effect, and other effects of the high entropy alloy intermediate layer 2. The high entropy alloy intermediate layer 2 can still reduce the formation of brittle phases, form high-density dislocations in the weld area, and simultaneously form a high-entropy solid solution structure, thereby improving the strength, toughness, and oxidation resistance of the joint.

[0040] Optionally, the heating step is performed under a vacuum environment.

[0041] In this optional embodiment, the vapor pressure of Cu increases significantly with increasing temperature. -4 Pa) environment, the external pressure is low, and the escape of Cu atoms is more likely to occur. At about 1100 ° C, the saturated vapor pressure of Cu has reached ~10 -3 Pa has been significantly volatilized in a vacuum and does not remain in the joint, ensuring the high-temperature performance of the joint. At the same time, due to the lack of oxygen in a vacuum, a dense oxide film (such as Cu2O or CuO) cannot be formed on the copper surface to inhibit volatilization. The Cu intermediate layer 3 can be almost completely volatilized, ensuring that there is no low-melting-point phase in the joint and improving the high-temperature resistance of the joint.

[0042] Optionally, after the steps of sequentially arranging the titanium-aluminum material 1, the solder composition and the nickel-based high-temperature alloy 4, a pressure of 0.1 to 0.5 MPa is applied to make the titanium-aluminum material 1, the high-entropy alloy intermediate layer 2 of the solder composition, the Cu intermediate layer 3 of the solder composition and the nickel-based high-temperature alloy 4 contact.

[0043] Optionally, in the step of increasing the temperature to 1100 to 1150° C., the temperature is increased at a rate of 5 to 20° C. / min.

[0044] The present invention is further described below with reference to specific embodiments.

[0045] Example 1, welding Ti3AlC2 ceramic / GH3536 joint.

[0046] GH3536 alloy is a nickel-based high-temperature alloy with a high iron content, which is mainly strengthened by solid solution of chromium and molybdenum.

[0047] 1. Selection of the composition and content of the high entropy alloy intermediate layer: The composition and atomic percentage of the high entropy alloy intermediate layer include: Ni: 25%, Cr: 5%, Fe: 5%, Zr: 25%, Hf: 10%, Cu: 10%, Sn: 20%.

[0048] 2. Welding steps: Pre-treat Ti3AlC2 ceramics and Ni-based high-temperature alloy GH3536 parent materials to remove surface oxide layers and contaminants; A high entropy alloy interlayer is placed between the base material Ti3AlC2 ceramic and GH3536, and a Cu interlayer is inserted between the high entropy alloy interlayer and the Ni-based high temperature alloy; In a vacuum environment, a pressure of 0.3 MPa was applied to ensure good contact between the interlayer and the base metal. The temperature was raised to 1100-1150°C at a rate of 10°C / min and kept at that temperature for 20 minutes. The Cu interlayer melted to form a liquid phase, which promoted element diffusion and formed a uniform weld. Temperature control or furnace cooling promotes the formation of high entropy solid solution and micro-nano dispersed structure, improves joint strength, and obtains Ti3AlC2 ceramic / GH3536 joint, such as Figure 2 As shown; Finally, the Cu and Sn elements in the high-entropy alloy intermediate layer and the Cu intermediate layer volatilize in a vacuum, ensuring that the joint has no low-melting-point phase and improving high-temperature resistance.

[0049] After testing, it was found that the room temperature shear strength of the Ti3AlC2 ceramic / GH3536 joints prepared multiple times was 350 to 450 MPa.

[0050] Example 2, welding Ti3AlC2 ceramic / GH3039 joint.

[0051] GH3039 nickel-based superalloy is a single-phase austenitic solid solution strengthened alloy with moderate thermal strength and good thermal fatigue resistance below 800°C and good oxidation resistance below 1000°C. It maintains stable microstructure over long periods of use and exhibits good cold formability and weldability.

[0052] 1. Selection of the composition and content of the high entropy alloy intermediate layer: The composition and atomic percentage of the high entropy alloy intermediate layer include: Ni: 25%, Cr: 5%, Fe: 5%, Zr: 25%, Hf: 10%, Cu: 10%, Sn: 20%.

[0053] 2. Welding steps: Pre-treat Ti3AlC2 ceramics and Ni-based high-temperature alloy GH3039 parent materials to remove surface oxide layers and contaminants; A high entropy alloy interlayer is placed between the base material Ti3AlC2 ceramic and GH3039, and a Cu interlayer is inserted between the high entropy alloy interlayer and the Ni-based high temperature alloy; In a vacuum environment, a pressure of 0.3 MPa was applied to ensure good contact between the interlayer and the base metal. The temperature was raised to 1100-1150°C at a rate of 10°C / min and kept at that temperature for 20 minutes. The Cu interlayer melted to form a liquid phase, which promoted element diffusion and formed a uniform weld. Temperature control or furnace cooling promotes the formation of high entropy solid solution and micro-nano dispersed structure, improves joint strength, and obtains Ti3AlC2 ceramic / GH3039 joint, such as Figure 3 As shown; Finally, the Cu and Sn elements in the high-entropy alloy intermediate layer and the Cu intermediate layer volatilize in a vacuum, ensuring that the joint has no low-melting-point phase and improving high-temperature resistance.

[0054] After testing, it was found that the room temperature shear strength of the Ti3AlC2 ceramic / GH3039 joints prepared multiple times was 350 to 450 MPa.

[0055] Example 3, welding TiAl-based composite material / GH3536 joint.

[0056] GH3536 alloy is a nickel-based high-temperature alloy with a high iron content, which is mainly strengthened by solid solution of chromium and molybdenum.

[0057] 1. Selection of the composition and content of the high entropy alloy intermediate layer: The composition and atomic percentage of the high entropy alloy intermediate layer include: Ni: 20%, Cr: 3%, Fe: 2%, Zr: 20%, Hf: 15%, Cu: 15%, Sn: 25%.

[0058] 2. Welding steps: Pre-treat TiAl-based composite materials and Ni-based high-temperature alloy GH3536 parent materials to remove surface oxide layers and contaminants; A high entropy alloy interlayer is placed between the parent material TiAl-based composite material and GH3536, and a Cu interlayer is inserted between the high entropy alloy interlayer and the Ni-based high-temperature alloy; In a vacuum environment, a pressure of 0.3 MPa was applied to ensure good contact between the interlayer and the base metal. The temperature was raised to 1100-1150°C at a rate of 5°C / min and kept at that temperature for 30 minutes. The Cu interlayer melted to form a liquid phase, which promoted element diffusion and formed a uniform weld. Temperature control or furnace cooling promotes the formation of high entropy solid solution and micro-nano dispersed structure, improves joint strength, and obtains TiAl-based composite material / GH3536 joint, such as Figure 4 As shown; Finally, the Cu and Sn elements in the high-entropy alloy intermediate layer and the Cu intermediate layer volatilize in a vacuum, ensuring that the joint has no low-melting-point phase and improving high-temperature resistance.

[0059] After testing, it was found that the room temperature shear strength of the TiAl-based composite material / GH3536 joints prepared multiple times was 400 to 450 MPa.

[0060] Example 4, welding TiAl alloy / GH3039 joint.

[0061] GH3039 nickel-based superalloy is a single-phase austenitic solid solution strengthened alloy with moderate thermal strength and good thermal fatigue resistance below 800°C and good oxidation resistance below 1000°C. It maintains stable microstructure over long periods of use and exhibits good cold formability and weldability.

[0062] 1. Selection of the composition and content of the high entropy alloy intermediate layer: The composition and atomic percentage of the high entropy alloy intermediate layer include: Ni: 30%, Cr: 8%, Fe: 7%, Zr: 30%, Hf: 5%, Cu: 5%, Sn: 15%.

[0063] 2. Welding steps: Pre-treat TiAl alloy and Ni-based high-temperature alloy GH3039 base materials to remove surface oxide layers and contaminants; A high entropy alloy intermediate layer is placed between the parent material TiAl alloy and GH3039, and a Cu intermediate layer is inserted between the high entropy alloy intermediate layer and the Ni-based high temperature alloy; In a vacuum environment, a pressure of 0.3 MPa was applied to ensure good contact between the interlayer and the base metal. The temperature was raised to 1100-1150°C at a rate of 20°C / min and kept at that temperature for 5 minutes. The Cu interlayer melted to form a liquid phase, which promoted element diffusion and formed a uniform weld. Temperature control or furnace cooling promotes the formation of high entropy solid solution and micro-nano dispersion structure, improves joint strength, and obtains TiAl alloy / GH3039 joint, such as Figure 5 As shown; Finally, the Cu and Sn elements in the high-entropy alloy intermediate layer and the Cu intermediate layer volatilize in a vacuum, ensuring that the joint has no low-melting-point phase and improving high-temperature resistance.

[0064] After testing, it was found that the room temperature shear strength of the TiAl alloy / GH3039 joints prepared multiple times was 450 to 500 MPa.

[0065] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A brazing material composition for connecting titanium-aluminum materials and nickel-based high-temperature alloys, characterized in that: The invention comprises a high entropy alloy intermediate layer (2) and a Cu intermediate layer (3) arranged in sequence, wherein the side of the high entropy alloy intermediate layer (2) away from the Cu intermediate layer (3) is used to connect to the titanium-aluminum material (1), and the side of the Cu intermediate layer (3) away from the high entropy alloy intermediate layer (2) is used to connect to the nickel-based high-temperature alloy (4).

2. The brazing filler metal composition for connecting titanium-aluminum materials and nickel-based high-temperature alloys according to claim 1, characterized in that: The high entropy alloy intermediate layer (2) comprises Ni, Cr, Fe, Zr, Hf, Cu and Sn.

3. The brazing filler metal composition for connecting titanium-aluminum series materials and nickel-based high-temperature alloys according to claim 2, characterized in that: In atomic percentage, the high entropy alloy intermediate layer (2) includes 20% to 30% Ni, 3% to 8% Cr, 2% to 7% Fe, 20% to 30% Zr, 5% to 15% Hf, 5% to 15% Cu and 15% to 25% Sn.

4. The brazing filler metal composition for connecting titanium-aluminum series materials and nickel-based high-temperature alloys according to claim 1, characterized in that: The titanium-aluminum series material (1) covers all alloys, intermetallic compounds, ceramics and composite materials based on Ti and Al.

5. The brazing filler metal composition for connecting titanium-aluminum series materials and nickel-based high-temperature alloys according to claim 1, characterized in that: The thickness ratio of the high entropy alloy intermediate layer (2) to the Cu intermediate layer (3) is less than 5.

6. A method for connecting titanium-aluminum material and nickel-based high-temperature alloy, characterized in that: Using the brazing filler metal composition for connecting titanium-aluminum materials and nickel-based high-temperature alloys according to any one of claims 1 to 5 comprises the following steps: Arranging the titanium-aluminum material (1), the solder composition, and the nickel-based high-temperature alloy (4) in sequence, so that the titanium-aluminum material (1), the high-entropy alloy intermediate layer (2) of the solder composition, the Cu intermediate layer (3) of the solder composition, and the nickel-based high-temperature alloy (4) are in contact with each other; When the temperature is raised to 1100 to 1150°C, the Cu intermediate layer (3) melts to form a liquid phase, forming a uniform weld.

7. The method for connecting titanium-aluminum material and nickel-based high-temperature alloy according to claim 6, characterized in that: The heating step is performed under a vacuum environment.

8. The method for connecting titanium-aluminum material and nickel-based high-temperature alloy according to claim 6, characterized in that: After the step of sequentially arranging the titanium-aluminum material (1), the solder composition, and the nickel-based high-temperature alloy (4), a pressure of 0.1 to 0.5 MPa is applied to bring the titanium-aluminum material (1), the high-entropy alloy intermediate layer (2) of the solder composition, the Cu intermediate layer (3) of the solder composition, and the nickel-based high-temperature alloy (4) into contact.

9. The method for connecting titanium-aluminum based materials and nickel-based high temperature alloys according to claim 6, characterized in that: In the step of increasing the temperature to 1100 to 1150° C., the temperature is increased at a rate of 5 to 20° C. / min.

10. The method for connecting titanium-aluminum material and nickel-based high-temperature alloy according to claim 6, characterized in that: After the step of heating to 1100 to 1150° C., the temperature is maintained for 5 to 30 minutes.

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