Method for diffusion bonding of Zr alloy by using Ti amorphous interlayer

Abstract

The invention discloses a method for diffusion bonding of Zr alloy by using a Ti amorphous interlayer, which is characterized in that an upper-layer Zr alloy base metal part and a lower-layer Zr alloy base metal part which are subjected to welding surface cleaning treatment and an interlayer alloy part are overlapped and then are subjected to diffusion welding to realize connection, the interlayer alloy part is made of Ti-based amorphous alloy foil, and during diffusion welding, the Ti-based amorphous alloy foil is subjected to diffusion bonding under a set pressure; heating according to a two-stage heating strategy: in the first stage, heating to about a crystallization initial temperature at a heating rate of 90-110 DEG C / min, and keeping the temperature and the pressure for 15-25 minutes; in the second stage, the temperature is increased to the target temperature at the speed of 35-45 DEG C / min, heat preservation and pressure maintaining are conducted for 55-65 min, and welding is completed; and after welding is completed, furnace cooling is performed to room temperature, and a product is taken out. The method is applied to diffusion welding connection between Zr alloys, interface atom diffusion can be better promoted, the welding temperature is reduced, and the interface bonding tightness degree is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal welding, and particularly to a diffusion welding connection technique using a Ti amorphous interlayer. Background Art

[0002] Zirconium (Zr) and its alloys have been widely used in the fields of nuclear industry, chemical industry, aerospace and biomedicine due to their low neutron absorption cross-section, excellent corrosion resistance, good high-temperature creep resistance and excellent biocompatibility. For large and complex zirconium alloy components, reliable connection is often achieved through welding.

[0003] Diffusion welding is a welding method in which two workpieces to be welded are tightly pressed together and heated in a vacuum or protective atmosphere furnace, so that microscopic plastic deformation occurs at the tiny unevenness of the two welding surfaces to achieve close contact. During the subsequent heating and holding process, atomic diffusion occurs to form a metallurgical connection. Usually, this type of diffusion welding is also called solid-phase diffusion. As a solid-phase welding process, the welding process is carried out in a vacuum, with almost no oxidation. The welding temperature is lower than that of fusion welding, and the attenuation of the base material performance is relatively lower. It is one of the preferred methods for achieving high-quality welding of Zr and its alloys. However, at present, the diffusion welding process temperature of Zr and its alloys is generally above 800 °C, and the base material still has a certain tendency of grain coarsening, which may have a negative impact on the performance of the welded component.

[0004] In order to reduce the diffusion welding temperature and optimize the joint structure and performance, previous studies have tried various technical paths including pre-hydrogen treatment of the base material, surface nanocrystallization pretreatment and introduction of an interlayer. Among them, although pre-hydrogen treatment can reduce the diffusion welding temperature to a certain extent, its operation process is complex, the requirement for hydrogen content control is extremely high, brittle phases are easily formed, and at the same time, the process cost and technical threshold are significantly increased, restricting its engineering application; although surface nanocrystallization treatment can increase the atomic diffusion rate, it requires additional equipment and processes, has poor adaptability to large or complex components, and is likely to affect the dimensional accuracy of the connection area.

[0005] In contrast, adding an intermediate layer is considered a simple and effective strategy to reduce the diffusion welding temperature and improve the joint quality. Patent CN114571055A once disclosed a method for realizing low-temperature diffusion bonding of zirconium alloy itself by using a Ti foil intermediate layer. In this invention, by adding a Ti foil intermediate layer, the phase transformation of zirconium alloy is achieved through the mutual diffusion of Ti and Zr during the welding process, and the low-temperature diffusion bonding of zirconium alloy is completed; a certain temperature reduction effect can be shown. However, this method still has the following deficiencies: (1) The above method mainly relies on the phase transformation reaction induced by the mutual diffusion between Zr and Ti to reduce the welding temperature. However, its phase transformation temperature range is narrow, and the atomic diffusion on both sides of the joint is insufficient, resulting in a still relatively high phase transformation temperature and difficult to guarantee the welding quality; the mechanical properties of the joint are low. (2) The intermediate layer does not undergo a complete phase transformation after welding, and the remaining intermediate layer may weaken the corrosion resistance of the joint and have a greater impact on the radiation resistance of the joint. Summary of the Invention

[0006] Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the present invention is: how to provide a method for diffusion bonding Zr alloy using a Ti amorphous intermediate layer that can better promote interface atomic diffusion, reduce the welding temperature, and improve the tightness of interface bonding.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions: A method for diffusion bonding Zr alloy using a Ti amorphous intermediate layer. After stacking the upper and lower Zr alloy base material components and the intermediate layer alloy component that have completed the cleaning treatment of the welding surface, diffusion welding is carried out to achieve connection. It is characterized in that the intermediate layer alloy component uses a Ti-based amorphous alloy foil. During diffusion welding, under a set pressure, it is heated according to a two-stage heating strategy: in the first stage, it is heated to around the initial crystallization temperature at a heating rate of 90 - 110 °C / min, and kept at a constant temperature and pressure for 15 - 25 min; in the second stage, it is heated to the target temperature at a rate of 35 - 45 °C / min, and kept at a constant temperature and pressure for 55 - 65 min to complete the welding; after the welding is completed, it is cooled to room temperature in the furnace, and the product is taken out.

[0008] In this way, the present method uses a Ti-based amorphous alloy as the intermediate layer and realizes welding through two-stage heating and pressure holding. The amorphous alloy is formed by ultra-rapid solidification. When the alloy solidifies, atoms do not have time to arrange and crystallize orderly. The obtained solid alloy has a long-range disordered structure. The molecules (or atoms, ions) that make up it do not show a regular periodicity in space, and there are no grains and grain boundaries in the crystalline alloy. In the first stage of this method, the temperature is relatively quickly raised to the initial crystallization temperature and held for a period of time while maintaining pressure. By utilizing the superplasticity of the Ti-based amorphous intermediate layer in the supercooled liquid region (between the glass transition temperature and the crystallization temperature), close bonding at the interface between the intermediate layer and the Zr base material is achieved at the initial stage of heating, making the atomic diffusion path shorter and the diffusion interface wider, creating favorable conditions for subsequent atomic diffusion and metallurgical bonding. At the same time, the intermediate layer crystallizes, forming fine-grained or nanocrystalline structures, providing high-density grain boundaries, and providing a fast channel for the diffusion of atoms between the Ti-based intermediate layer atoms and the Zr alloy base material atoms, thereby achieving effective pre-bonding at a relatively low temperature. After heating to the initial crystallization temperature, hold for about 20 minutes while maintaining pressure. If the holding time is too short, the crystallization of the Ti amorphous intermediate layer is insufficient, it is difficult to form high-density grain boundaries, the atomic diffusion channel is limited, the amorphous plastic deformation is insufficient, and the interface pores are not fully closed, affecting subsequent atomic diffusion and joint quality; if the holding time is too long, other amorphous-forming elements will form a continuous compound layer with the Zr base material at the interface, affecting subsequent atomic diffusion between the interfaces and the mechanical properties of the joint.

[0009] In the second stage, the temperature is relatively slowly continued to be raised above the phase change temperature of the Ti amorphous intermediate layer and then held for a longer time, so that the crystal structure changes from hexagonal close-packed (HCP) to body-centered cubic (BCC). The BCC structure has larger octahedral interstices, higher solid solubility and vacancy concentration, thus significantly increasing the atomic diffusion rate, further accelerating the interdiffusion of interface elements, and finally achieving high-quality metallurgical connection. In this way, this solution solves the technical problems existing in the existing diffusion welding process of Zr alloys, such as the coarsening of the base material grains under high-temperature conditions and the low mechanical properties of the joint. By utilizing the superplasticity of Ti amorphous between the glass transition temperature and the crystallization temperature, close bonding at the interface is achieved. Further, above the crystallization temperature, the crystallization of the Ti-based amorphous intermediate layer and the low-temperature phase change of the entire intermediate layer itself synergistically promote atomic diffusion, reduce the welding temperature, optimize the joint structure and properties, and the obtained post-weld product has no residual intermediate layer. After heating in the second stage, hold for about 60 minutes while maintaining pressure. If the time is too short, the atomic diffusion at the interface is insufficient, there are coarse compounds in the diffusion zone, and it is difficult to achieve sufficient metallurgical bonding; if the holding time is too long, it is easy to cause grain coarsening, reducing the mechanical properties and structural stability of the joint.

[0010] Furthermore, the heating rate in the first stage is 100 °C / min, and the holding and pressurizing time is 20 min; the heating rate in the second stage is 40 °C / min, and the holding and pressurizing time is 60 min. This can better achieve the above-mentioned effect.

[0011] Furthermore, the Zr alloy grades are Zr-0, Zr-1, Zr-2, Zr-3, Zr-4 or Zr-5. They are mature existing products with reliable performance and are convenient to directly purchase and implement.

[0012] Preferably, the Ti content in the Ti-based amorphous alloy foil is greater than 40 at.%, and the other amorphous forming elements include Zr and Ni elements, and also include at least one element among Cu, Be, Si and Al. The content of a single element is less than 40 at.%, maintaining the dominant position of Ti in the diffusion reaction process and simultaneously optimizing the stability of the Ti-based amorphous.

[0013] In the solution, the Zr content in the other amorphous forming elements is greater than 20 at.%. On the one hand, Zr can increase the degree of atomic size mismatch of the amorphous, contributing to the formation of the amorphous. On the other hand, Zr is an element of the base metal to be welded and can inhibit the generation of compounds in the welded joint.

[0014] In the solution, the Ni content in the other amorphous forming elements is greater than 10 at.%. On the one hand, Ni can improve the amorphous forming ability, contributing to increasing the crystallization temperature and thermal stability. On the other hand, Ni can form fine and dispersed strengthening phases with the Zr base metal, enhancing the mechanical properties of the joint.

[0015] In the solution, at least one element among Cu, Be, Si and Al is included to improve the amorphous forming ability of the Ti-based amorphous intermediate layer, regulate the crystallization temperature and contribute to refining the joint microstructure.

[0016] Among them, Cu, Si and Al elements are prone to form brittle compounds with the Zr base metal during the welding process, and their respective contents should be less than 10 at.%. Among the other amorphous forming elements, Be has the advantages of low mass and small atomic radius, but it is highly toxic and has a high vapor pressure, and is likely to volatilize during the welding process, causing pore or porosity defects. It should be added with caution, and its content should be less than 5 at.%.

[0017] Preferably, the thickness of the Ti-based amorphous alloy foil is 10 - 30 μm. If it is too thin, the element diffusion source is insufficient, resulting in insufficient diffusion of the joint and unable to achieve effective connection; if it is too thick, it will cause residue in the intermediate layer, affecting the corrosion resistance and irradiation performance of the joint.

[0018] Preferably, before welding, the surfaces to be welded of the alloy base metal parts are successively polished with silicon carbide sandpapers of 400# - 3000# and polished to a mirror state using polishing paste and metallographic polishing cloth.

[0019] Preferably, the size of the Ti-based amorphous alloy foil is consistent with the size of the surface to be welded, and it is gently polished with 3000# sandpaper to remove the oxide scale.

[0020] Preferably, the alloy base material component after grinding treatment and the Ti-based amorphous alloy foil are placed in absolute ethanol or acetone for ultrasonic cleaning to remove the surface oil stain.

[0021] Preferably, during the whole welding process, a thermocouple is used to directly contact the alloy base material component through the graphite mold to realize temperature detection and monitoring, so as to ensure the accurate control of the welding temperature.

[0022] Preferably, the pressure applied on both sides of the alloy base material component during the welding process is maintained at 10 - 50 Mpa (the optimal is 30 Mpa), that is, the set pressure. If the set pressure is too low, it is difficult for the plastic deformation of the joint to fully close the interface pores, affecting the initial diffusion and subsequent metallurgical bonding; if the set pressure is too high, it may cause the amorphous intermediate layer to be extruded during the heating process, resulting in large plastic deformation of the base material, and then affecting the weld quality and welding accuracy.

[0023] Preferably, before welding, the initial crystallization temperature, phase transition temperature, and initial melting temperature of the Ti-based amorphous alloy foil can be measured by differential scanning calorimetry (DSC).

[0024] Preferably, the temperature in the first stage of heating is controlled within the range of ±10°C of the initial crystallization temperature of the Ti-based amorphous alloy foil, ensuring the synergistic effect of intermediate layer crystallization and superplasticity, and improving the interface pre-connection effect.

[0025] Preferably, the target temperature in the second stage of heating is to heat above the phase transition temperature of the Ti-based amorphous alloy foil and below the initial melting temperature. In this way, it can promote the mutual diffusion between interface atoms through phase transition while preventing the extrusion of the melted amorphous.

[0026] Preferably, after welding, it should be cooled with the furnace, and the cooling rate does not exceed 10°C / min to prevent stress concentration from causing joint tissue defects.

[0027] The beneficial effects of the present invention are as follows: it can significantly reduce the welding temperature required for diffusion welding of Zr alloys, avoid the coarsening of the base material grains, and improve the joint tissue stability and comprehensive mechanical properties; the weld structure is dense, without obvious pores and continuous brittle compound layers, and can achieve equal-strength or even super-strong connection with the base material; the process has strong adaptability, simple operation, and is suitable for the connection of various Zr alloys.

[0028] In summary, the present invention is applied to the diffusion welding connection between Zr alloys, which can better promote the diffusion of interface atoms, reduce the welding temperature, and improve the tightness of interface bonding. Description of the Drawings

[0029] Figure 1Schematic diagram of the structure between the base metal component and the intermediate layer alloy component during welding by the method of the present invention.

[0030] Figure 2 Scanning images of the diffusion welded joints obtained in Examples 1 to 4 of the present invention respectively.

[0031] Figure 3 Enlarged scanning image of the center position of the diffusion welded joint obtained in Example 4 of the present invention. Detailed implementation manners

[0032] The present invention will be further described in detail below in conjunction with the specific implementation manners.

[0033] Implementation manner: A method for diffusion bonding Zr alloy using a Ti amorphous intermediate layer. Refer to Figure 1 , after stacking the upper and lower Zr alloy base metal parts 1 and the intermediate layer alloy part 2 that have completed the cleaning treatment of the welding surface, diffusion welding is carried out to achieve connection. The feature is that the intermediate layer alloy part uses a Ti-based amorphous alloy foil. During diffusion welding, under a set pressure, it is heated according to a two-stage heating strategy: in the first stage, it is heated to around the initial crystallization temperature at a heating rate of 100 °C / min, and kept warm and under pressure for 20 min; in the second stage, it is heated to the target temperature at a rate of 40 °C / min, and kept warm and under pressure for 60 min to complete the welding; after the welding is completed, it is cooled to room temperature in the furnace, and the product is taken out.

[0034] Among them, the Zr alloy grades are Zr-0, Zr-1, Zr-2, Zr-3, Zr-4 or Zr-4.

[0035] Among them, the Ti content in the Ti-based amorphous alloy foil is greater than 40 at.%, and other amorphous forming elements include Zr and Ni elements, and also include at least one element among Cu, Be, Si and Al, and the content of a single element is less than 40 at.%. In the solution, the Zr content in other amorphous forming elements is greater than 20 at.%. The Ni content in other amorphous forming elements is greater than 10 at.%. In the solution, at least one element among Cu, Be, Si and Al is included. Cu, Si and Al elements are prone to form brittle compounds with the Zr base metal during the welding process, and their respective contents should be less than 10 at.%. Be among other amorphous forming elements has the advantages of low mass and small atomic radius, but it is highly toxic and has a high vapor pressure, and is easy to volatilize during the welding process, causing hole or porosity defects, and should be added carefully, and its content should be less than 5 at.%.

[0036] Among them, the thickness of the Ti-based amorphous alloy foil is 10 - 30 μm. If it is too thin, the element diffusion source is insufficient, resulting in insufficient diffusion of the joint and unable to achieve effective connection; if it is too thick, it will cause residue in the intermediate layer, affecting the corrosion resistance and irradiation performance of the joint.

[0037] During implementation, before welding, the surface to be welded of the alloy base metal component is successively polished with silicon carbide sandpaper of 400# to 3000#, and then polished to a mirror state using polishing paste and metallographic polishing cloth.

[0038] During implementation, the size of the Ti-based amorphous alloy foil is the same as that of the surface to be welded, and it is gently polished with 3000# sandpaper to remove the oxide scale. The alloy base metal component and the Ti-based amorphous alloy foil after grinding treatment are placed in absolute ethanol or acetone for ultrasonic cleaning to remove surface oil stains.

[0039] During implementation, throughout the welding process, a thermocouple is used to directly contact the alloy base metal component through the graphite mold to achieve temperature detection and monitoring, so as to ensure accurate control of the welding temperature.

[0040] During implementation, the pressure applied on both sides of the alloy base metal component during the welding process is maintained at 10 to 50 Mpa (the optimal is 30 Mpa), that is, the set pressure. If the set pressure is too low, it is difficult for the plastic deformation of the joint to fully close the interface pores, affecting the initial diffusion and subsequent metallurgical bonding; if the set pressure is too high, it may cause the amorphous intermediate layer to be extruded during the heating process, causing large plastic deformation of the base metal, and then affecting the weld quality and welding accuracy.

[0041] During implementation, before welding, the initial crystallization temperature, phase transformation temperature, and initial melting temperature of the Ti-based amorphous alloy foil can be measured by differential scanning calorimetry (DSC).

[0042] During implementation, in the first stage, the heating temperature is controlled within the range of ±10°C of the initial crystallization temperature of the Ti-based amorphous alloy foil to ensure the synergistic effect of intermediate layer crystallization and superplasticity and improve the interface pre-connection effect.

[0043] During implementation, the target temperature for heating in the second stage is to heat above the phase transformation temperature of the Ti-based amorphous alloy foil and below the initial melting temperature. This can promote the mutual diffusion of atoms at the interface through phase transformation while preventing the extrusion of the melted amorphous.

[0044] During implementation, after welding, it should be cooled with the furnace, and the cooling rate does not exceed 10°C / min to prevent stress concentration from causing joint structure defects.

[0045] In order to better verify the implementation effect of the present invention, on the basis of meeting the requirements defined in the above implementation methods, the applicant used specific different materials and different parameters to conduct the following four specific examples as experimental examples to verify the effect of the present invention.

[0046] Example 1

[0047] In the first embodiment, the Ti-based amorphous alloy foil is made of a material with the grade of B–Ti57CuZrNi, which is exactly within the required ratio range of the Ti-based amorphous alloy foil of this application, facilitating direct purchase and implementation. Its glass transition temperature, initial crystallization temperature, phase transition temperature, and initial melting temperature are 390°C, 462°C, 721°C, and 821°C respectively.

[0048] In this embodiment, the Zr alloy base material component is a Zr-2 bar, and the maximum diffusion welding temperature is 630°C, which is lower than the phase transition temperature of the Ti-based amorphous alloy foil intermediate layer.

[0049] First, the Zr-2 bar is processed into two cylindrical sections with a diameter of Φ10mm and a length of 10mm. The welding surfaces are successively polished with 400#, 800#, 1000#, 1500#, 2000#, and 3000# silicon carbide sandpapers, and polished to a mirror surface on a metallographic polishing machine with polishing paste.

[0050] A Ti-based amorphous alloy foil with a thickness of 20μm is selected as the intermediate layer. The Ti-based amorphous alloy foil is cut into a circular piece with the same cross-sectional size as the Zr base material, and the surface oxide scale is gently removed with 3000# sandpaper.

[0051] The processed Zr base material and Ti amorphous foil are placed in absolute ethanol for ultrasonic cleaning for 10 minutes to remove surface oil stains and impurities; then the stacked alloy base material components are placed in a graphite mold in a hot pressing furnace. The thermocouple passes through the mold hole and is in direct contact with the specimen to monitor the welding temperature in real time.

[0052] The welding process is carried out in a two-stage heating manner. First, under a pressure of 30MPa, it is heated to 390°C at a rate of 100°C / min and kept at this temperature for 20 minutes while maintaining the pressure. Subsequently, it is continuously heated to 630°C at a rate of 40°C / min and kept at this temperature for 60 minutes while maintaining the pressure at 30MPa to achieve sufficient diffusion. After the diffusion is completed, the specimen is cooled with the furnace, and the cooling rate is controlled within 10°C / min to prevent stress concentration at the joint.

[0053] Embodiment Two

[0054] The difference between this second embodiment and the first embodiment is that the maximum welding temperature of the Zr alloy base material component used is 680°C. That is, during welding, it is heated to 680°C in the second stage. The rest is the same as in the first embodiment.

[0055] Embodiment Three

[0056] The difference between Example 3 and Example 1 is that the maximum welding temperature of the Zr alloy base metal component used is 730 °C, which is higher than the phase transition temperature of the Ti amorphous interlayer. That is, during welding, the temperature is raised to 730 °C in the second stage. The rest is the same as in Example 1.

[0057] Example 4

[0058] The difference between Example 3 and Example 1 is that the maximum welding temperature of the Zr alloy base metal component used is 780 °C, which is higher than the phase transition temperature of the Ti amorphous interlayer. That is, during welding, the temperature is raised to 780 °C in the second stage. The rest is the same as in Example 1.

[0059] The applicant conducted tensile fracture tests on the welded products obtained from the above four groups of examples, and the test results are as follows in the table. The unit of tensile strength in the table is MPa, and the unit of elongation is %.

[0060]

[0061] See Figure 2 and Figure 3 As for the fracture locations and weld positions of the products in each group of examples, the following is observed: In Example 1, the crystallized interlayer consists of very fine grains; a continuous compound layer is formed at the interface. In Example 2, the thickness of the crystallized interlayer decreases, and the fine grains grow; the continuous compound layer thickens. In Example 3, the original interlayer and the continuous compound disappear, only discontinuous strip-like rich compounds remain, and fine acicular Widmanstatten structures appear in the weld. In Example 4, the continuous compound layer in the weld completely disappears, and dispersed 0.5–1 μm particle strengthening phases 6 are distributed in the diffusion zone.

[0062] By comparing the four groups of examples, it can be seen that although fine grains are obtained at low temperatures below the phase transition temperature of the interlayer, the presence of the compound layer seriously deteriorates the mechanical properties of the joint. When the temperature reaches above the phase transition temperature, the continuous compound in the joint disappears and at the same time fine and dispersed second phases are formed, significantly improving the mechanical properties of the joint and achieving equal-strength connection with the base metal.

Claims

1. A method for diffusion bonding Zr alloys using a Ti amorphous interlayer. After stacking the upper and lower Zr alloy base material components with the welding surfaces cleaned and the interlayer alloy component, diffusion welding is carried out to achieve connection. It is characterized in that The intermediate layer alloy component is made of Ti-based amorphous alloy foil. During diffusion welding, under a set pressure, it is heated according to a two-stage heating strategy: in the first stage, it is heated to around the initial crystallization temperature at a heating rate of 90 - 110 °C / min, and heat and pressure are maintained for 15 - 25 min; in the second stage, it is heated to the target temperature at a rate of 35 - 45 °C / min, and heat and pressure are maintained for 55 - 65 min to complete the welding; after welding is completed, it is cooled in the furnace to room temperature, and the product is taken out.

2. The method for diffusion bonding of Zr alloy using a Ti amorphous intermediate layer according to claim 1, wherein, In the first stage, the heating rate is 100 °C / min, and the time for maintaining heat and pressure is 20 min; in the second stage, the heating rate is 40 °C / min, and the time for maintaining heat and pressure is 60 min.

3. The method for diffusion bonding of Zr alloy using a Ti amorphous intermediate layer as claimed in claim 1, wherein The Zr alloy grades are Zr-0, Zr-1, Zr-2, Zr-3, Zr-4 or Zr-5.

4. The method for diffusion bonding of Zr alloy using a Ti amorphous intermediate layer as claimed in claim 1, wherein The Ti content in the Ti-based amorphous alloy foil is greater than 40 at.%, and other amorphous forming elements include Zr and Ni elements, and also include at least one of Cu, Be, Si and Al elements, with the content of each single element being less than 40 at.%; Among other amorphous forming elements, the Zr content is greater than 20 at.%; Among other amorphous forming elements, the Ni content is greater than 10 at.%; Among other amorphous forming elements, the contents of Cu, Si and Al elements are each less than 10 at.%; the Be element content is less than 5 at.%.

5. The method for diffusion bonding of Zr alloy using a Ti amorphous intermediate layer as claimed in claim 1, wherein, The thickness of the Ti-based amorphous alloy foil is 10 - 30 μm.

6. The method for diffusion bonding of Zr alloy using a Ti amorphous interlayer as claimed in claim 1, wherein Before welding, the surfaces to be welded of the alloy base material components are successively polished with silicon carbide sandpapers of 400# - 3000# and polished to a mirror state using polishing paste and metallographic polishing cloth; The size of the Ti-based amorphous alloy foil is the same as that of the surface to be welded, and it is gently polished with 3000# sandpaper to remove the oxide skin; The alloy base material components and the Ti-based amorphous alloy foil after polishing treatment are placed in anhydrous ethanol or acetone for ultrasonic cleaning to remove surface oil stains.

7. The method for diffusion bonding of Zr alloy using a Ti amorphous interlayer as claimed in claim 1, characterized in that, During the welding process, the pressure applied on both sides of the alloy base material components is maintained at 10 - 50 Mpa.

8. The method for diffusion bonding of Zr alloy using a Ti amorphous intermediate layer as claimed in claim 1, wherein, In the first stage, the heating temperature is controlled within the range of ±10 °C of the initial crystallization temperature of the Ti-based amorphous alloy foil.

9. The method for diffusion bonding of Zr alloy using a Ti amorphous intermediate layer as claimed in claim 1, wherein The target temperature reached in the second stage is above the phase transition temperature and below the initial melting temperature of the Ti-based amorphous alloy foil.

10. The method for diffusion bonding a Zr alloy using a Ti amorphous intermediate layer as claimed in claim 1, wherein After welding is completed, it is cooled in the furnace, and the cooling rate does not exceed 10 °C / min.

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