A copper-hafnium composite wire and a processing technology thereof

Abstract

The application discloses a copper-hafnium composite wire and a processing technology thereof, and the processing technology comprises the following steps: performing cleaning treatment, drying treatment and laser cladding treatment on the surface of a hafnium rod material to obtain a copper-hafnium composite rod blank; then performing first peeling treatment, multi-pass hot rotary swaging deformation, annealing treatment, wire drawing treatment, recrystallization annealing treatment, second peeling treatment, finished product annealing treatment and polishing treatment on the copper-hafnium composite rod blank in sequence to obtain the copper-hafnium composite wire. The copper-hafnium composite wire is prepared by compounding copper metal on the surface of hafnium metal, and a metallurgical bonding layer can be formed after the copper-hafnium composite wire is brazed with silver-copper alloy filler metal of an electrode copper base, so that the conductivity and the heat conductivity of the whole electrode weld zone can be improved, and the service life of the electrode is improved. Meanwhile, the copper-hafnium composite wire can save the invisible loss of hafnium material in the metal processing process due to the protection of the pure copper material surface, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of materials processing technology. Specifically, this invention relates to a copper hafnium composite wire and its processing technology. Background Technology

[0002] Hafnium has a low electron work function and is often used as a plasma emitter in plasma cutting electrodes. The electrode is typically fabricated by brazing a hafnium wire to a copper substrate. The electrode's cooling rate affects its lifespan, and the cooling effect is closely related to the bonding strength between the hafnium wire and the copper substrate. Brazing uses a silver-copper alloy filler metal, which can form a ternary eutectic or hafnium-containing metallic compound between the hafnium wire and the copper substrate. This means that a metallurgical bond layer may not form between the hafnium wire and the copper substrate. This reduces the electrical and thermal conductivity of the entire electrode weld zone, thus affecting the electrode's lifespan.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of the present invention propose a copper-hafnium composite wire processing technology that is easy to operate and has strong process controllability.

[0005] One embodiment of the present invention provides a processing technology for copper hafnium composite wire, comprising the following steps:

[0006] (1) Clean and dry the surface of the hafnium bar;

[0007] (2) The surface of the dried hafnium rod is subjected to laser cladding treatment to obtain copper-hafnium composite rod blank;

[0008] (3) The copper hafnium composite rod blank is subjected to the first peeling process through a wire drawing die;

[0009] (4) The copper-hafnium composite billet after peeling is subjected to multiple hot rotary forging deformation to obtain a copper-hafnium composite rotary forging bar;

[0010] (5) Anneal the copper-hafnium composite rotary forging bar;

[0011] (6) The copper-hafnium composite rotary forging bar after annealing in step (5) is subjected to wire drawing, intermediate product recrystallization annealing, and second peeling treatment in sequence to obtain copper-hafnium composite wire.

[0012] (7) The copper hafnium composite wire is subjected to finished product annealing treatment;

[0013] (8) Polish the copper hafnium composite wire after annealing in step (7) to obtain the copper hafnium composite wire.

[0014] This invention provides a copper-hafnium composite wire by bonding copper metal to the surface of hafnium metal. When the copper-hafnium composite wire is brazed to the copper electrode substrate with silver-copper alloy brazing filler metal, a metallurgical bonding layer is formed, which can improve the conductivity and thermal conductivity of the entire electrode weld area, thereby increasing the service life of the electrode. At the same time, during the metal processing, the pure copper material protects the surface of the copper-hafnium composite wire, which can save the invisible loss of hafnium material during processing and reduce production costs. Moreover, the processing method is simple, easy to operate, and highly controllable.

[0015] In some embodiments of the present invention, in step (1), the cleaning agent used in the cleaning process is an alkaline degreasing agent;

[0016] And / or, the drying process is carried out at a temperature of 46°C to 82°C for a time of 0.5h to 1h.

[0017] In some embodiments of the present invention, in step (2), the cladding material used in the laser cladding process is pure copper powder or pure copper wire, and the cladding thickness is 1mm to 2mm.

[0018] In some embodiments of the present invention, in step (3), during the first peeling process, the diameter removal amount of the copper hafnium composite rod blank is ≤0.3mm.

[0019] In some embodiments of the present invention, in step (4), the single-pass deformation amount of the multi-pass hot rotary forging deformation is 9% to 25%, the total deformation amount is 35% to 60%, the heating temperature is 700°C to 800°C, and the heating time is 0.2h to 0.5h.

[0020] And / or, the dimensions of the copper-hafnium composite rotary forging bar are Φ8mm~Φ9mm.

[0021] In some embodiments of the present invention, in step (5), the annealing process is carried out in a vacuum annealing furnace with a vacuum pressure <1.33×10⁻⁶. -2 Pa, annealing temperature is 750℃~800℃, holding time is 1h~2h.

[0022] In some embodiments of the present invention, in step (6), the single-pass deformation amount of the wire drawing process is 9% to 12%, and recrystallization annealing is performed when the total deformation amount is 35% to 55%.

[0023] And / or, the annealing temperature for the recrystallization annealing treatment of the intermediate product is 650℃~750℃, and the holding time is 1h~2h;

[0024] And / or, the thickness of the pure copper on the surface of the copper-hafnium composite wire is 0.1mm to 0.3mm, and the size of the copper-hafnium composite wire is Φ1mm to Φ4mm.

[0025] In some embodiments of the present invention, in step (7), the finished product annealing treatment is carried out in a vacuum annealing furnace with a vacuum pressure <1.33×10⁻⁶. -2 Pa, annealing temperature is 650℃~750℃, holding time is 1h~2h.

[0026] In some embodiments of the present invention, in step (8), the polishing treatment uses 600-1200 mesh silicon carbide abrasive belt; and after the polishing treatment, the diameter reduction of the copper hafnium composite wire is 0.013 mm to 0.07 mm, and the surface roughness is ≤ Ra0.4 μm.

[0027] Another aspect of this invention provides a copper-hafnium composite wire, which is prepared by the above-described processing technology.

[0028] In the copper-hafnium composite wire of this invention, the copper and hafnium are metallurgically bonded. When used as an electrode cutting wire, it can form a metallurgical bonding layer with the copper substrate by brazing with silver-copper alloy brazing filler metal, which can improve the service life of the electrode. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification and claims of this invention are intended to cover non-exclusive inclusion.

[0031] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is understood that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0034] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0035] One embodiment of the present invention provides a processing technology for copper hafnium composite wire, comprising the following steps:

[0036] (1) Surface treatment: The surface of the hafnium bar is cleaned and dried;

[0037] (2) Laser cladding: The surface of the dried hafnium rod is subjected to laser cladding treatment to obtain copper-hafnium composite rod blank;

[0038] (3) Surface treatment: The copper hafnium composite rod blank is subjected to the first peeling process by a wire drawing die;

[0039] (4) Hot rotary forging deformation: The copper-hafnium composite billet after peeling is subjected to multiple hot rotary forging deformation to obtain copper-hafnium composite rotary forging bar;

[0040] (5) Annealing: The copper-hafnium composite rotary forging bar is annealed;

[0041] (6) Wire drawing: The copper hafnium composite rotary forging bar after annealing in step (5) is sequentially subjected to wire drawing, intermediate product recrystallization annealing, and second peeling to obtain copper hafnium composite wire.

[0042] (7) Annealing: The copper hafnium composite wire is subjected to finished product annealing treatment;

[0043] (8) Polishing: Polish the copper hafnium composite wire after annealing in step (7) to obtain the copper hafnium composite wire.

[0044] In some specific embodiments, in step (1), the cleaning agent used in the cleaning process is an alkaline degreasing agent;

[0045] And / or, the drying process is carried out at a temperature of 46°C to 82°C for a time of 0.5h to 1h.

[0046] In some specific embodiments, in step (2), the laser cladding process uses pure copper powder or pure copper wire as the cladding material, and the cladding thickness is 1mm to 2mm. The inventors have found that if the cladding thickness is too thick, it will lead to material waste, and the excess copper composite layer needs to be removed during the final wire drawing and peeling process; however, if the cladding thickness is too thin, the copper composite layer will peel off and expose the hafnium substrate due to factors such as deformation and thinning and surface damage during the wire drawing process. Therefore, it is advantageous to control the cladding thickness between 1mm and 2mm in the embodiments of the present invention.

[0047] In some specific embodiments, during step (3), the diameter removal amount of the copper hafnium composite rod blank is ≤0.3mm during the first peeling process.

[0048] In some specific embodiments, in step (4), the deformation amount of a single pass in the multi-pass hot rotary forging is 9% to 25%, the total deformation amount is 35% to 60%, the heating temperature is 700℃ to 800℃, and the heating time is 0.2h to 0.5h. The inventors have found that if the deformation amount of a single pass is too large, it will cause defects such as folding on the surface of the rotary forged bar. However, if the deformation amount of a single pass is too small, it will cause stress cracking defects in the metal bar due to repeated forging. Therefore, in the embodiments of the present invention, the deformation amount of a single pass is controlled within the range of 9% to 25%.

[0049] And / or, the dimensions of the copper-hafnium composite rotary forging bar are Φ8mm~Φ9mm.

[0050] In some specific embodiments, in step (5), the annealing process is carried out in a vacuum annealing furnace with a vacuum pressure <1.33×10⁻⁶. -2 Pa, the annealing temperature is 750℃~800℃, and the holding time is 1h~2h. Through annealing, the metal material in the copper-hafnium composite rotary forging bar can undergo complete recrystallization, which improves the metal plasticity and is beneficial to subsequent metal processing deformation. In this embodiment of the invention, the annealing temperature is controlled between 750℃ and 800℃. If the annealing temperature is too high, it will cause the metal grains to grow and reduce the metal plasticity; but if the annealing temperature is too low, the metal material will not recrystallize completely, which will also reduce the metal plasticity.

[0051] In some specific embodiments, in step (6), the single-pass deformation amount of the wire drawing process is 9% to 12%, and recrystallization annealing is performed when the total deformation amount is 35% to 55%.

[0052] And / or, the annealing temperature for the recrystallization annealing treatment of the intermediate product is 650℃~750℃, and the holding time is 1h~2h; by performing recrystallization annealing treatment on the copper hafnium composite rotary forging bar after wire drawing, the plasticity of the metal material can be improved; if the recrystallization annealing treatment temperature is too high, it will cause the metal grains to grow and reduce the metal plasticity; but if the recrystallization annealing treatment temperature is too low, the metal material will not recrystallize completely, which will also reduce the metal plasticity.

[0053] And / or, the thickness of the pure copper on the surface of the copper-hafnium composite wire is 0.1mm to 0.3mm, and the size of the copper-hafnium composite wire is Φ1mm to Φ4mm. By peeling the copper-hafnium composite forged bar, the thickness of the metallic copper on the surface of the wire and the diameter of the final finished wire can be effectively controlled.

[0054] In some specific embodiments, in step (7), the finished product annealing treatment is carried out in a vacuum annealing furnace with a vacuum pressure <1.33×10⁻⁶. -2 The annealing temperature is 650℃~750℃, and the holding time is 1h~2h. Annealing of copper-hafnium composite wire can improve the plasticity of the metal material, reduce the resistance, and improve the conductivity.

[0055] In some specific embodiments, in step (8), the polishing process uses 600-1200 mesh silicon carbide abrasive belt; and after polishing, the diameter reduction of the copper hafnium composite wire is 0.013 mm to 0.07 mm, and the surface roughness is ≤ Ra0.4 μm. By polishing the copper hafnium composite wire, a good surface roughness can be ensured.

[0056] Another aspect of this invention provides a copper-hafnium composite wire, which is prepared by the above-described processing technology.

[0057] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Unless otherwise stated, all raw materials used in the embodiments are conventional commercially available products, or can be prepared by known methods, and the experimental methods not specified in the embodiments are conventional methods and conditions well known in the art.

[0058] Example 1

[0059] A processing technology for copper hafnium composite wire includes the following steps:

[0060] (1) Surface treatment: The surface of the Φ9mm hafnium bar is cleaned with an alkaline degreasing agent to remove oil stains, and then dried at 60℃ for 0.5h.

[0061] (2) Laser cladding: The surface of the dried hafnium rod is subjected to laser cladding treatment. The cladding material is pure copper powder, and the cladding thickness is controlled to be 1 mm to obtain copper-hafnium composite rod blank;

[0062] (3) Surface treatment: The copper hafnium composite billet is first peeled by drawing a wire drawing die to remove impurities from the surface of the copper hafnium composite billet;

[0063] (4) Hot rotary forging deformation: The copper-hafnium composite billet after peeling is continuously subjected to multiple passes of hot rotary forging deformation on a rotary forging equipment. The deformation amount of a single pass is controlled at about 10%, and the total deformation amount is about 60%. The heating temperature is 700℃ and the heating time is 0.5h to obtain a copper-hafnium composite rotary forging bar with a size of Φ8mm.

[0064] (5) Annealing: The copper-hafnium composite rotary forging bar is annealed in a vacuum annealing furnace, wherein the vacuum pressure is <1.33×10 -2 Pa, annealing temperature is 780℃, holding time is 2h;

[0065] (6) Wire drawing: The copper-hafnium composite rotary forging bar after annealing in step (5) is first drawn on a wire drawing machine, and the deformation amount per pass is controlled to be 10%; when the total deformation amount reaches 55%, the intermediate product recrystallization annealing treatment is carried out, the annealing temperature is 720℃, and the holding time is 1h; then the second peeling treatment is carried out, leaving a thickness of 0.2mm of pure copper on the surface of the copper-hafnium composite wire, and a copper-hafnium composite wire with a size of Φ2.4mm is obtained;

[0066] (7) Annealing: The copper-hafnium composite wire is annealed in a vacuum annealing furnace, wherein the vacuum pressure is <1.33×10 -2 Pa, annealing temperature is 700℃, holding time is 2h;

[0067] (8) Polishing: The copper hafnium composite wire after annealing in step (7) is polished on a wire abrasive belt polishing equipment. The abrasive belt is 800 mesh silicon carbide, the diameter of the copper hafnium composite wire is removed by 0.02 mm, and the surface roughness after polishing is ≤Ra0.4μm. The copper hafnium composite wire can then be obtained.

[0068] Example 2

[0069] A processing technology for copper hafnium composite wire includes the following steps:

[0070] (1) Surface treatment: The surface of the Φ8mm hafnium bar is cleaned with an alkaline degreasing agent to remove oil stains, and then dried at 60℃ for 0.5h.

[0071] (2) Laser cladding: The surface of the dried hafnium rod is subjected to laser cladding treatment. The cladding material is pure copper powder, and the cladding thickness is controlled to be 1 mm to obtain copper-hafnium composite rod blank;

[0072] (3) Surface treatment: The copper hafnium composite billet is first peeled by drawing a wire drawing die to remove impurities from the surface of the copper hafnium composite billet;

[0073] (4) Hot rotary forging deformation: The copper-hafnium composite billet after peeling is continuously subjected to multiple passes of hot rotary forging deformation on a rotary forging equipment. The deformation amount of a single pass is controlled at about 10%, and the total deformation amount is about 60%. The heating temperature is 700℃ and the heating time is 0.5h to obtain a copper-hafnium composite rotary forging bar with a size of 7mm.

[0074] (5) Annealing: The copper-hafnium composite rotary forging bar is annealed in a vacuum annealing furnace, wherein the vacuum pressure is <1.33×10 -2 Pa, annealing temperature is 780℃, holding time is 2h;

[0075] (6) Wire drawing: The copper-hafnium composite forged bar after annealing in step (5) is first drawn on a wire drawing machine, and the deformation amount per pass is controlled to be 10%; when the total deformation amount reaches 55%, the intermediate product recrystallization annealing treatment is carried out, the annealing temperature is 720℃, and the holding time is 1h; then the second peeling treatment is carried out, leaving a thickness of 0.2mm of pure copper on the surface of the copper-hafnium composite wire, and a copper-hafnium composite wire with a size of Φ2.0mm is obtained;

[0076] (7) Annealing: The copper-hafnium composite wire is annealed in a vacuum annealing furnace, wherein the vacuum pressure is <1.33×10 -2 Pa, annealing temperature is 700℃, holding time is 2h;

[0077] (8) Polishing: The copper hafnium composite wire after annealing in step (7) is polished on a wire abrasive belt polishing equipment. The abrasive belt is 800 mesh silicon carbide, the diameter of the copper hafnium composite wire is removed by 0.02 mm, and the surface roughness after polishing is ≤Ra0.4μm. The copper hafnium composite wire can then be obtained.

[0078] Example 3

[0079] A processing technology for copper hafnium composite wire includes the following steps:

[0080] (1) Surface treatment: The surface of the Φ10mm hafnium bar is cleaned with an alkaline degreasing agent to remove oil stains, and then dried at 60℃ for 0.5h.

[0081] (2) Laser cladding: The surface of the dried hafnium rod is subjected to laser cladding treatment. The cladding material is pure copper powder, and the cladding thickness is controlled to be 1 mm to obtain copper-hafnium composite rod blank;

[0082] (3) Surface treatment: The copper hafnium composite billet is first peeled by drawing a wire drawing die to remove impurities from the surface of the copper hafnium composite billet;

[0083] (4) Hot rotary forging deformation: The copper-hafnium composite billet after peeling is continuously subjected to multiple passes of hot rotary forging deformation on a rotary forging equipment. The deformation amount of a single pass is controlled at about 10%, and the total deformation amount is about 60%. The heating temperature is 700℃ and the heating time is 0.5h to obtain a copper-hafnium composite rotary forging bar with a size of Φ8mm.

[0084] (5) Annealing: The copper-hafnium composite rotary forging bar is annealed in a vacuum annealing furnace, wherein the vacuum pressure is <1.33×10 -2 Pa, annealing temperature is 780℃, holding time is 2h;

[0085] (6) Wire drawing: The copper-hafnium composite rotary forging bar after annealing in step (5) is first drawn on a wire drawing machine, and the deformation amount per pass is controlled to be 10%; when the total deformation amount reaches 55%, the intermediate product recrystallization annealing treatment is carried out, the annealing temperature is 720℃, and the holding time is 1h; then the second peeling treatment is carried out, leaving a thickness of 0.2mm of pure copper on the surface of the copper-hafnium composite wire, and a copper-hafnium composite wire with a size of Φ3.0mm is obtained;

[0086] (7) Annealing: The copper-hafnium composite wire is annealed in a vacuum annealing furnace, wherein the vacuum pressure is <1.33×10 -2 Pa, annealing temperature is 700℃, holding time is 2h;

[0087] (8) Polishing: The copper hafnium composite wire after annealing in step (7) is polished on a wire abrasive belt polishing equipment. The abrasive belt is 800 mesh silicon carbide, the diameter of the copper hafnium composite wire is removed by 0.02 mm, and the surface roughness after polishing is ≤Ra0.4μm. The copper hafnium composite wire can then be obtained.

[0088] The copper-hafnium composite wire prepared using the processing technology of this invention exhibits excellent electrical and thermal conductivity when the copper is fused onto the metal hafnium substrate, forming a metallurgical bond with extremely low resistance between the two. This results in good electrical and thermal conductivity, extending the electrode's lifespan. In contrast, when a pure hafnium electrode is brazed to the copper substrate of a plasma cutting electrode using a silver-copper alloy, the lack of a metallurgical bond leads to higher resistance, higher heat generation, and increased electrode burn-out.

[0089] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0090] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A processing technology for copper-hafnium composite wire, characterized in that, Includes the following steps: (1) Clean and dry the surface of the hafnium bar; (2) The surface of the dried hafnium rod is subjected to laser cladding treatment. The cladding material is pure copper powder or pure copper wire, and the cladding thickness is 1mm to 2mm to obtain copper-hafnium composite rod blank. (3) The copper hafnium composite rod blank is subjected to the first peeling process through a wire drawing die; (4) The copper-hafnium composite billet after peeling is subjected to multi-pass hot rotary forging to obtain a copper-hafnium composite rotary forging bar; wherein the deformation amount of each pass in the multi-pass hot rotary forging is 9% to 25%, and the total deformation amount is 35% to 60%; (5) Anneal the copper-hafnium composite rotary forging bar; (6) The copper-hafnium composite forged bar after annealing in step (5) is subjected to wire drawing, intermediate product recrystallization annealing, and second peeling treatment in sequence to obtain copper-hafnium composite wire; the thickness of pure copper on the surface of the copper-hafnium composite wire is 0.1mm to 0.3mm, and the size of the copper-hafnium composite wire is Φ1mm to Φ4mm. (7) The copper hafnium composite wire is subjected to finished product annealing treatment; (8) Polish the copper hafnium composite wire after annealing in step (7) to obtain the copper hafnium composite wire.

2. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (1), the cleaning agent used in the cleaning process is an alkaline degreasing agent; And / or, the drying process is carried out at a temperature of 46°C to 82°C for a time of 0.5h to 1h.

3. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (3), during the first peeling process, the diameter removal amount of the copper hafnium composite rod blank is ≤0.3mm.

4. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (4), the heating temperature for the multi-pass hot rotary forging deformation is 700℃~800℃, and the heating time is 0.2h~0.5h; And / or, the dimensions of the copper-hafnium composite rotary forging bar are Φ8mm~Φ9mm.

5. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (5), the annealing process is carried out in a vacuum annealing furnace with a vacuum pressure <1.33×10⁻⁶. -2 Pa, annealing temperature is 750℃~800℃, holding time is 1h~2h.

6. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (6), the single-pass deformation amount of the wire drawing process is 9% to 12%, and recrystallization annealing is performed when the total deformation amount is 35% to 55%. And / or, the annealing temperature for the recrystallization annealing treatment of the intermediate product is 650℃~750℃, and the holding time is 1h~2h.

7. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (7), the finished product annealing treatment is carried out in a vacuum annealing furnace with a vacuum pressure <1.33×10⁻⁶. -2 Pa, annealing temperature is 650℃~750℃, holding time is 1h~2h.

8. The copper-hafnium composite wire processing technology according to claim 1, characterized in that, In step (8), the polishing process uses 600-1200 mesh silicon carbide abrasive belt; and after polishing, the diameter reduction of the copper hafnium composite wire is 0.013 mm to 0.07 mm, and the surface roughness is ≤ Ra0.4 μm.

9. A copper-hafnium composite wire, characterized in that, The copper-hafnium composite wire is prepared by the processing technology described in any one of claims 1-8.