Method for diffusion bonding of heterogeneous titanium alloy based on high-entropy alloy interlayer

Abstract

The invention provides a method for diffusion bonding of a heterogeneous titanium alloy based on a high-entropy alloy interlayer, and relates to the technical field of heterogeneous titanium alloy bonding, the method comprises the following steps: step 1, rolling and machining a high-entropy alloy ingot to obtain a high-entropy alloy foil; the high-entropy alloy cast ingot is composed of the following elements in atomic percent: Ti <-15 > Co <-15 > Fe <-15 > Mo <-10 > Cr <-10 > Ni <-15 > Zr <-5 > Y, secondly, the Ti150 alloy base material, the high-entropy alloy foil and the Ti180 alloy base material are stacked in sequence, the high-entropy alloy foil is located between the Ti150 alloy base material and the Ti180 alloy base material, and a heterogeneous alloy assembly is obtained; and thirdly, the heterogeneous alloy assembly is subjected to vacuum diffusion welding treatment, and the heterogeneous alloy diffusion welding joint is obtained. According to the method, strengthening and toughening of the heterogeneous titanium alloy diffusion welding joint are achieved through the self-designed Ti-based high-entropy alloy middle layer, the heterogeneous titanium alloy is connected through the Ti-based high-entropy alloy middle layer, and therefore the diffusion welding joint with high toughness is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of dissimilar titanium alloy joining, and particularly relates to a method for diffusion joining dissimilar titanium alloys based on a high-entropy alloy interlayer. Background Art

[0002] As a material for aeroengines, it must have excellent high-temperature performance. Titanium alloy is a lightweight material with low density, high strength, and high temperature resistance. Therefore, titanium alloy has become the first choice material for aeroengines, which can effectively reduce the self-weight of aeroengines and thus improve the thrust-to-weight ratio. With the evolution of aero power systems towards higher thrust-to-weight ratios, the engineering application of the integral blisk technology has put forward multi-dimensional performance requirements for the titanium alloy material system. Research shows that under the coupled working conditions of high temperature and high stress, the degradation of the mechanical properties of traditional titanium alloys has become a key factor restricting the service reliability of compressor components. The new generation of blisk components not only need to have excellent thermal strength matching, but also require the material to maintain stable creep resistance and oxidation resistance within a wide temperature range. The Ti150 alloy exhibits significantly better comprehensive high-temperature performance than traditional titanium alloys through multi-component alloying design. Its strengthening mechanism is as follows: 1) a substructure strengthening network composed of β-phase stabilizing elements; 2) an interface strengthening effect generated by the interaction between nano-precipitates and dislocations; 3) an improvement in environmental resistance brought about by the self-healing property of the surface oxide layer. Microstructural characterization shows that the gradient microstructure formed during the thermal exposure process of this alloy can effectively coordinate the stress distribution under thermo-mechanical loads. It is worth noting that the Ti150 alloy components prepared based on additive manufacturing technology exhibit typical epitaxial growth columnar crystal characteristics, and this anisotropic tissue configuration significantly improves the thermal shock resistance of blisk components. With the continuous optimization of thermo-mechanical processing technology, the application potential of this material system in the hot-end components of advanced aeroengines is gradually being verified by engineering. Currently, the joining methods for dissimilar titanium alloys mainly include welding methods such as inert gas welding, electron beam welding, and friction welding. However, for traditional fusion welding methods, defects such as cracks, oxidation, and non-uniform microstructure will occur during the welding process. Using diffusion welding can effectively reduce the thermal stress of the joint and has less influence on the joint microstructure.

[0003] In the current reports on dissimilar titanium alloys, some researchers have carried out electron beam welding on TiAl / TC4 dissimilar titanium alloys, but Al-phase tissue is generated during the welding process, resulting in the joint breaking along the fusion line. Some researchers have also studied the diffusion bonding of Ti-43Al-9V / TC4. Although a good joint can be obtained under the conditions of 920 °C / 45 MPa / 2 h, α-Ti is generated during the diffusion process of the two alloys. 3Al brittle phase. When traditional metal interlayers such as pure copper, pure nickel, and aluminum-based alloys are used in the diffusion welding of heterogeneous titanium alloys, intermetallic compounds are likely to be generated. These products will lead to a decrease in the toughness of the joint and become the path for crack initiation and propagation. At the same time, element segregation may also be triggered, further weakening the interfacial bonding. Summary of the Invention

[0004] Aiming at the problem of easy generation of intermetallic compounds when traditional metal interlayers are used in the diffusion welding of heterogeneous titanium alloys mentioned in the above background technology, the present invention proposes a method for diffusion bonding heterogeneous titanium alloys based on a high-entropy alloy interlayer. By using a high-entropy alloy interlayer to connect heterogeneous titanium alloys, a diffusion welded joint with high strength and toughness is obtained.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The present invention provides a method for diffusion bonding heterogeneous titanium alloys based on a high-entropy alloy interlayer, including the following steps: Step 1: Roll and machine a high-entropy alloy ingot to obtain a high-entropy alloy foil; wherein, the high-entropy alloy ingot is composed of elements with the following atomic percentages: Ti-15Co-15Fe-15Mo-10Cr-10Ni-15Zr-5Y; Step 2: Stack the Ti150 alloy (the Ti150 alloy is composed of elements with the following atomic percentages: 85.36Ti-5.62Al-3.8Sn-3.6Zr-0.7Nb-0.49Mo-0.37Si-0.06C) base material, the high-entropy alloy foil, and the Ti180 alloy (the Ti180 alloy is composed of elements with the following atomic percentages: 81.77Ti-6.09Al-2.05Sn-3.94Zr-6.15Mo) base material in sequence, so that the high-entropy alloy foil is located between the Ti150 alloy base material and the Ti180 alloy base material to obtain a heterogeneous alloy combination; Step 3: Perform vacuum diffusion welding treatment on the heterogeneous alloy combination to obtain a heterogeneous alloy diffusion welded joint.

[0006] As a further description of the present invention, the high-entropy alloy ingot is prepared by arc melting.

[0007] As a further description of the present invention, in Step 1, the high-entropy alloy ingot needs to be cut and surface-treated before rolling.

[0008] As a further description of the present invention, in Step 1, the rolling treatment of the high-entropy alloy ingot is specifically: perform multiple cold rolling treatments on the high-entropy alloy ingot to obtain a foil with a thickness of 0.1 mm - 0.2 mm.

[0009] As a further illustration of the present invention, in Step 1, the machining treatment specifically is: segmentally cut and grind the rolled foil to a thickness of 100 μm - 130 μm, and then successively polish, clean, and dry the foil to obtain a high-entropy alloy foil.

[0010] As a further illustration of the present invention, before Step 2, the method further includes successively cutting, grinding and polishing, cleaning, and drying the Ti150 alloy base material and the Ti180 alloy base material.

[0011] As a further illustration of the present invention, in Step 3, the vacuum diffusion welding treatment is carried out in a vacuum diffusion furnace.

[0012] As a further illustration of the present invention, in Step 3, the welding process conditions of the vacuum diffusion welding treatment specifically are: the first stage: heat from room temperature to 300 °C at a heating rate of 10 °C / min and hold at 300 °C for 10 min; the second stage: heat from 300 °C to 600 °C at a heating rate of 10 °C / min and hold at 600 °C for 10 min; the third stage: heat from 600 °C to 800 °C at a heating rate of 10 °C / min and hold at 800 °C for 10 min; the fourth stage: heat from 800 °C to the welding target temperature of 820 °C - 910 °C at a heating rate of 10 °C / min, and the heating ends; the fifth stage: hold at the welding target temperature for 1 h while applying a pressure of 5 MPa - 10 MPa; after the holding ends, the sample is cooled to room temperature with the furnace and the pressure returns to zero, and the welding is completed.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention realizes the strengthening and toughening of the dissimilar titanium alloy diffusion welded joint by using a self-designed Ti-based high-entropy alloy intermediate layer. The dissimilar titanium alloys are connected by using the Ti-based high-entropy alloy intermediate layer, thereby obtaining a diffusion welded joint with high strength and toughness.

[0014] The present invention adopts a diffusion welding connection method and successfully connects dissimilar titanium alloys by using a high-entropy intermediate layer. Moreover, the obtained weld seam has no defects, realizing high-quality diffusion connection of dissimilar titanium alloys.

[0015] Other features and advantages of this technical solution will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing this technical solution. The objectives and other advantages of this technical solution can be achieved and obtained through the structures specifically pointed out in the written specification and the drawings.

[0016] The following further describes the technical solution of this technical solution in detail through the drawings and embodiments. Brief Description of the Drawings

[0017] The drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the description. Together with the embodiments of the technical solution, they are used to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention. In the drawings: Figure 1 It is a scanning electron microscope morphology diagram of the diffusion welded joint of Ti150 - high entropy alloy intermediate layer - Ti180 obtained in Embodiment 1 of the present invention.

[0018] Figure 2 It is a scanning electron microscope morphology diagram of the diffusion welded joint of Ti150 - traditional high entropy alloy intermediate layer - Ti180 obtained in Comparative Example 1 of the present invention.

[0019] Figure 3 It is a scanning electron microscope morphology diagram of the diffusion welded joint of Ti150 - traditional high entropy alloy intermediate layer - Ti180 obtained in Comparative Example 2 of the present invention.

[0020] Figure 4 It is a fracture morphology diagram of the diffusion welded joint of Ti150 - high entropy alloy intermediate layer - Ti180 obtained in Embodiment 1 of the present invention. Detailed Embodiments

[0021] The following describes the preferred embodiments of the technical solution of the present invention with reference to the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the technical solution of the present invention, and are not used to limit the technical solution of the present invention.

[0022] The present invention provides a method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer, including the following steps: Step 1: Rolling and machining a high entropy alloy ingot to obtain a high entropy alloy foil; wherein, the high entropy alloy ingot is composed of elements with the following atomic percentages: Ti - 15Co - 15Fe - 15Mo - 10Cr - 10Ni - 15Zr - 5Y.

[0023] The element design principles of the high-entropy alloy intermediate layer in the present invention are as follows: In order to solve the defects such as cracks, oxidation, and non-uniform microstructure caused by existing welding technologies. The present invention designs the high-entropy alloy elements and their specific atomic percentages as above, and realizes the high reaction energy release characteristics of the material through the synergistic effect of highly active components. The single-phase solid solution structure characteristics and weak metal bonding characteristics of the above high-entropy alloy system enable the lattice atoms to easily undergo de-embedding movement during high-speed impact, quickly releasing energy. Specifically, since Ti is the main element of the base material, the high-entropy alloy designed in the present invention is a Ti-based high-entropy alloy, and the Ti element therein can ensure the crystal structure compatibility between the intermediate layer and the base material, reducing the interfacial lattice mismatch. Ti atoms preferentially migrate along the grain boundaries of the base material during high-temperature diffusion welding to form a defect-free transition layer; the strong β-stabilizing elements Mo, Cr, Fe, Co, Ni in the high-entropy alloy form a dynamic balance with the α-stabilizing elements such as Al, Sn, Zr in the base material, and their mutual diffusion with Ti preferentially occupies the β-Ti lattice sites; the introduction of Mo and Cr in the high-entropy alloy further reduces the eutectoid transformation temperature of the β phase. At the same time, Mo is a high-melting-point element, and its slow diffusion characteristics combined with the "hysteresis effect" of the high-entropy alloy significantly reduce the interfacial segregation rate of light elements such as Al and Sn, thereby improving the plastic deformation ability of the joint. Zr in the high-entropy alloy forms a continuous solid solution with the corresponding elements in the base material, reducing the grain boundary energy and inhibiting element segregation. The unique lattice distortion effect of the high-entropy alloy, through the elastic strain field introduced by elements with large atomic radii such as Mo, and the solid solution strengthening of Zr, synergistically maintain good coordinated deformation ability while increasing the strength. This "high strength - moderate toughness" matching characteristic effectively inhibits crack initiation. Fe and Co in the high-entropy alloy lower the stacking fault energy of the matrix, promoting the decomposition of dislocations into partial dislocations with higher mobility and delaying strain localization; while the solid solution atoms of Mo and Cr act as strong pinning points, hindering the long-range slip of dislocations and forming a dynamic strong-toughness balance. Y in the high-entropy alloy can segregate at the grain boundaries to refine the grains, increasing the grain boundary ratio to absorb deformation energy.

[0024] Specifically, the above high-entropy alloy ingot is prepared by arc melting.

[0025] Specifically, in step one, before rolling the high-entropy alloy ingot, the high-entropy alloy ingot needs to be cut and surface-treated. For example, the obtained high-entropy alloy ingot is processed to the target size by a wire electrical discharge machine, and then the cut high-entropy alloy ingot is surface-treated.

[0026] Specifically, in step one, the rolling treatment of the high-entropy alloy ingot is: the high-entropy alloy ingot is subjected to multiple cold rolling treatments to obtain a foil; specifically, the thickness of the foil obtained by cold rolling is preferably 0.1 mm - 0.2 mm.

[0027] Specifically, in Step 1, the machining process is as follows: The rolled foil is cut into segments and polished to a thickness of 100 μm - 130 μm, and then the foil is polished, cleaned, and dried in sequence to obtain a high-entropy alloy foil. For example, the cold-rolled foil is cut into segments, and then the foil is polished using 400#, 800#, 1500#, and 2000# sandpapers in sequence to a thickness of 100 - 130 μm. After that, the polished foil is polished using SiO 2 -H 2 O 2 polishing agent, and finally the foil is ultrasonically cleaned with alcohol for 10 min and then dried to obtain a high-entropy alloy foil.

[0028] Step 2: Stack the Ti150 alloy base material, the high-entropy alloy foil, and the Ti180 alloy base material in sequence, with the high-entropy alloy foil positioned between the Ti150 alloy base material and the Ti180 alloy base material to obtain a heterogeneous alloy combination.

[0029] Specifically, before Step 2, the method further includes cutting, grinding and polishing, cleaning, and drying the Ti150 alloy base material and the Ti180 alloy base material in sequence. For example, the Ti150 alloy base material and the Ti180 alloy base material are processed into a cuboid structure using a wire electrical discharge machine; the surface of the titanium alloy cuboid is polished using 400#, 800#, 1500#, and 2000# sandpapers in sequence, and then SiO 2 -H 2 O 2 polishing agent is used for polishing treatment, and finally the treated titanium alloy cuboid is ultrasonically cleaned with alcohol for 10 min and then dried.

[0030] Step 3: Perform vacuum diffusion welding on the heterogeneous alloy combination to obtain a heterogeneous alloy diffusion welded joint.

[0031] Specifically, in Step 3, the vacuum diffusion welding is carried out in a vacuum diffusion furnace. The welding process conditions for the vacuum diffusion welding are specifically as follows: The first stage: Heat from room temperature to 300 °C at a heating rate of 10 °C / min and hold for 10 min at 300 °C; the second stage: Heat from 300 °C to 600 °C at a heating rate of 10 °C / min and hold for 10 min at 600 °C; the third stage: Heat from 600 °C to 800 °C at a heating rate of 10 °C / min and hold for 10 min at 800 °C; the fourth stage: Heat from 800 °C to the welding target temperature of 820 °C - 910 °C at a heating rate of 10 °C / min, and the heating ends; the fifth stage: Hold for 1 h at the welding target temperature while applying a pressure of 5 MPa - 10 MPa; after the holding ends, the sample is cooled to room temperature with the furnace and the pressure returns to zero, and the welding is completed.

[0032] The following is an illustration in combination with specific embodiments: Embodiment 1

[0033] A method for diffusion bonding heterogeneous titanium alloys based on a high-entropy alloy interlayer is realized through the following steps: Step 1: Prepare a high-entropy alloy ingot by arc melting; the prepared high-entropy alloy ingot is composed of elements with the following atomic percentages: Ti-15Co-15Fe-15Mo-10Cr-10Ni-15Zr-5Y, and the element purity is greater than 99.9 wt%.

[0034] Step 2: Use a wire electrical discharge machine to process the high-entropy alloy ingot obtained in Step 1 into a cuboid with dimensions of 25 mm × 25 mm × 5 mm; perform surface treatment on the cut high-entropy alloy ingot; subject the surface-treated high-entropy alloy ingot to multiple cold rolling operations to obtain a foil with a thickness of 0.15 mm; cut the cold-rolled foil into segments, and then successively polish the foil with 400#, 800#, 1500#, and 2000# sandpapers until the thickness reaches 100 μm. After that, polish the polished foil with SiO 2 -H 2 O 2 polishing agent, and finally ultrasonically clean the foil with alcohol for 10 min and then dry it to obtain a high-entropy alloy foil.

[0035] Step 3: Use a wire electrical discharge machine to process both the Ti150 alloy base material and the Ti180 alloy base material into cuboids with dimensions of 15 mm × 10 mm × 5 mm; successively polish the surfaces of the titanium alloy cuboids with 400#, 800#, 1500#, and 2000# sandpapers, and then polish them with SiO 2 -H 2 O 2 polishing agent, and finally ultrasonically clean the treated titanium alloy cuboids with alcohol for 10 min and then dry them.

[0036] Step 4: Stack the Ti150 alloy cuboid obtained in Step 3, the high-entropy alloy foil obtained in Step 2, and the Ti180 alloy cuboid obtained in Step 3 in sequence, with the high-entropy alloy foil located between the Ti150 alloy cuboid and the Ti180 alloy cuboid, to obtain a heterogeneous alloy combination.

[0037] Step 5: Put the heterogeneous alloy combination obtained in Step 4 into a vacuum diffusion furnace for diffusion welding. The specific welding process conditions are as follows: The first stage: Heat from room temperature to 300 °C at a heating rate of 10 °C / min and hold for 10 min at 300 °C; The second stage: Heat from 300 °C to 600 °C at a heating rate of 10 °C / min and hold for 10 min at 600 °C; The third stage: Heat from 600 °C to 800 °C at a heating rate of 10 °C / min and hold for 10 min at 800 °C; The fourth stage: Heat from 800 °C to the welding target temperature of 820 °C at a heating rate of 10 °C / min, and the heating ends; The fifth stage: Hold for 1 h at 820 °C while applying a pressure of 5 MPa; After the holding ends, the sample is cooled to room temperature with the furnace and the pressure returns to zero, and the welding is completed.

[0038] In this embodiment, the tensile strength of the Ti150-high entropy alloy interlayer-Ti180 joint reached 938 MPa.

[0039] Example 2

[0040] In Step 2, a foil with a thickness of 0.1 mm is obtained by cold rolling. After the cold-rolled foil is segmented and cut, it is directly polished with SiO 2 -H 2 O 2 polishing agent; The welding target temperature in Step 5 is 870 °C, and the rest is the same as in Example 1. In this embodiment, the tensile strength of the Ti150-high entropy alloy interlayer-Ti180 joint reached 857 MPa.

[0041] Example 3

[0042] In Step 2, a foil with a thickness of 0.2 mm is obtained by cold rolling. The cold-rolled foil is segmented and cut, and then the foil is polished with 400#, 800#, 1500#, and 2000# sandpapers in sequence until the thickness is 130 μm; The welding target temperature in Step 5 is 910 °C, and the rest is the same as in Example 1. In this embodiment, the tensile strength of the Ti150-high entropy alloy interlayer-Ti180 joint reached 820 MPa.

[0043] Example 4

[0044] The welding target temperature in Step 5 is 870 °C, and the pressure is 10 MPa, and the rest is the same as in Example 1. In this embodiment, the tensile strength of the Ti150-high entropy alloy interlayer-Ti180 joint reached 895 MPa.

[0045] Example 5

[0046] The welding temperature in Step 5 is 910 °C and the pressure is 10 MPa, and the rest is the same as in Example 1. The tensile strength of the Ti150 - high - entropy alloy interlayer - Ti180 joint obtained in this example reached 836 MPa.

[0047] Comparative Example 1 In Step 1, an arc melting method is used to prepare a high - entropy alloy ingot; the prepared high - entropy alloy ingot is composed of elements with the following atomic percentages: Ti - 30Fe - 20Ni - 10Cr - 10Y; the rest is the same as in Example 1.

[0048] The composition of the high - entropy alloy interlayer used in this comparative example does not contain Co, Mo, and Zr elements. By comparison Figure 1 、 Figure 2 it can be seen that brittle intermetallic compound phases are significantly formed in the welded joints using the traditional high - entropy alloy interlayer, accompanied by microscopic pores and crack defects. However, no brittle phases appear in the welded joints using the high - entropy alloy interlayer of the present invention. Through tensile experiments, it can be obtained that the tensile strength of the Ti150 - traditional high - entropy alloy interlayer - Ti180 diffusion - welded joint obtained using the traditional high - entropy alloy interlayer is only 596 MPa; the tensile strength of the Ti150 - high - entropy alloy interlayer - Ti180 diffusion - welded joint obtained using the high - entropy alloy interlayer of the present invention reaches up to 938 MPa at most. Figure 4 Figure 14 is the fracture morphology diagram of the Ti150 - high - entropy alloy interlayer - Ti180 diffusion - welded joint obtained in Example 1. After observing the fracture surface, it is found that the fracture mechanism is ductile fracture. Therefore, by using the high - entropy alloy interlayer of the present invention to inhibit the formation of brittle phases and reduce the defect density, the mechanical properties of the welded joint are effectively optimized and improved.

[0049] Comparative Example 2 In Step 1, an arc melting method is used to prepare a high - entropy alloy ingot; the prepared high - entropy alloy ingot is composed of elements with the following atomic percentages: Ti - 30Nb - 20Ta - 10Hf - 10Al; the rest is the same as in Example 1.

[0050] A traditional high - entropy alloy interlayer is used in this comparative example. The composition of the high - entropy alloy interlayer used in this comparative example is quite different from that in Example 1. By Figure 3 it can be seen that there are no obvious defects in the diffusion - welded joints obtained in this comparative example. However, through tensile experiments, it is obtained that the tensile strength of the Ti150 - traditional high - entropy alloy interlayer - Ti180 diffusion - welded joint obtained using the traditional high - entropy alloy interlayer in this comparative example is only 517 MPa, and the joint performance drops significantly.

[0051] Obviously, those skilled in the art can make various modifications and variations to this technical solution without departing from the spirit and scope of this technical solution. Thus, if these modifications and variations of this technical solution fall within the scope of the claims of this technical solution and its equivalent technologies, then this technical solution is also intended to include these modifications and variations.

Claims

1. A method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer, characterized in that: The steps include: Step 1: rolling and machining a high entropy alloy ingot to obtain a high entropy alloy foil; wherein the high entropy alloy ingot is composed of the following elements in atomic percentage: Ti-15Co-15Fe-15Mo-10Cr-10Ni-15Zr-5Y; Step 2: stacking the Ti150 alloy base material, the high entropy alloy foil and the Ti180 alloy base material in sequence, so that the high entropy alloy foil is located between the Ti150 alloy base material and the Ti180 alloy base material, to obtain a heterogeneous alloy assembly; Step three: subjecting the heterogeneous alloy assembly to vacuum diffusion welding to obtain a heterogeneous alloy diffusion welding joint.

2. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer according to claim 1, characterized in that: The high entropy alloy ingot is prepared by arc melting.

3. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer according to claim 1, characterized in that: In step one, the high entropy alloy ingot needs to be cut and surface treated before rolling.

4. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer according to claim 1, characterized in that: In step 1, the rolling process of the high entropy alloy ingot is specifically as follows: the high entropy alloy ingot is subjected to multiple cold rolling processes to obtain a foil with a thickness of 0.1 mm to 0.2 mm.

5. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer according to claim 1, characterized in that: In step one, the mechanical processing is specifically as follows: the rolled foil is cut into sections and polished to a thickness of 100 μm-130 μm, and then the foil is polished, cleaned and dried in sequence to obtain a high entropy alloy foil.

6. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer according to claim 1, characterized in that: Before step 2, the method further comprises cutting, grinding, polishing, cleaning and drying the Ti150 alloy base material and the Ti180 alloy base material in sequence.

7. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer according to claim 1, characterized in that: In step three, the vacuum diffusion welding process is performed in a vacuum diffusion furnace.

8. The method for diffusion bonding heterogeneous titanium alloys based on a high entropy alloy intermediate layer as claimed in claim 1, characterized in that: In step 3, the welding process conditions of the vacuum diffusion welding treatment are specifically as follows: first stage: heating from room temperature to 300°C at a heating rate of 10°C / min, and keeping at 300°C for 10 minutes; The second stage: heating from 300°C to 600°C at a heating rate of 10°C / min, and keeping at 600°C for 10 minutes; The third stage: heating from 600 ℃ to 800 ℃ at a heating rate of 10 ℃ / min, and keeping at 800 ℃ for 10 minutes; the fourth stage: heating from 800 ℃ to the welding target temperature of 820 ℃~910 ℃ at a heating rate of 10 ℃ / min, and the heating is completed; the fifth stage: keeping at the welding target temperature for 1 hour while applying 5MPa~10MPa pressure; after the insulation is completed, the sample is cooled to room temperature with the furnace and the pressure returns to zero, and the welding is completed.

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