Preparation method of a copper-tungsten composite material and the copper-tungsten composite material

Abstract

The present invention discloses a preparation method of a copper-tungsten composite material, comprising the steps of: material preparation: taking copper rods and tungsten rods, and performing degreasing and ultrasonic cleaning on the copper rods and tungsten rods; mold loading: first placing the tungsten rods into the forming holes of a graphite mold, and then placing the copper rods on top of the tungsten rods, wherein the bottom end of the copper rod has a frustum-shaped portion, and an obtuse angle α is formed between the side surface of the frustum-shaped portion and the side surface of the tungsten rod; furnace loading: feeding the graphite mold with the copper rods and tungsten rods placed therein into a vacuum furnace; vacuum pumping: pumping vacuum for the vacuum furnace, and the vacuum degree is 10-3 - 10-5 Pa; vacuum melting: heating the vacuum furnace for vacuum melting, and the melting temperature is 1200 - 1320 °C; high-temperature holding: holding at 1200 - 1320 °C for 5 - 10 minutes; controlled cooling: obtaining a composite material after cooling; post-treatment: performing heat treatment and machining on the composite material. Compared with the prior art, the present invention can achieve the preparation of a high-quality copper-tungsten composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of welding, and particularly relates to a preparation method of a copper-tungsten composite material and a copper-tungsten composite material. Background Art

[0002] In the field of material connection, the development of welding technology has always promoted the progress of the manufacturing industry. As an advanced welding process, vacuum brazing has been widely used in many high-end manufacturing fields due to its unique technical advantages.

[0003] Vacuum brazing is a brazing process carried out in a vacuum environment. Under high-temperature conditions, the filler metal exhibits good wettability and diffusion, and then firmly connects the workpieces together. Since the entire welding process is carried out in a vacuum, the occurrence of oxidation can be effectively avoided, greatly improving the welding quality. This advantage makes vacuum brazing an indispensable connection technology in fields with extremely high requirements for materials and welding quality, such as aerospace, electronic information, precision machinery manufacturing, etc., and is particularly suitable for the connection of high-demand materials and complex structures.

[0004] However, the vacuum brazing process itself has extremely strict requirements for operating conditions and workpiece states. Precise control of process parameters such as temperature, vacuum degree, and holding time is crucial. These process problems remain to be further solved. These problems not only limit the further popularization and application of vacuum brazing technology but also restrict the development of related high-end manufacturing industries. Based on this, this case proposes a preparation method of a copper-tungsten composite material and a copper-tungsten composite material. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a copper-tungsten composite material and a copper-tungsten composite material, which can achieve the preparation of high-quality copper-tungsten composite materials.

[0006] The above technical purpose of the present invention is achieved through the following technical solutions:

[0007] A preparation method of a copper-tungsten composite material includes the steps of:

[0008] Material preparation: Take copper rods and tungsten rods, and degrease and ultrasonically clean the copper rods and tungsten rods to remove impurities and oxide layers;

[0009] Molding: First, place the tungsten rod into the forming hole of the graphite mold, and then place the copper rod on top of the tungsten rod. The bottom end of the copper rod has a frustum portion, and an obtuse angle α is formed between the side surface of the frustum portion and the side surface of the tungsten rod. The design of the frustum shape at the bottom end of the copper rod enables the melted copper to fall and roll along the surface of the tungsten rod when the copper rod melts;

[0010] Furnace loading: Feed the graphite mold containing the copper rod and tungsten rod into the vacuum furnace;

[0011] Vacuum pumping: Pump the vacuum furnace to a vacuum degree of 10 -3 -10 -5 Pa;

[0012] Vacuum melting: Heat up the vacuum furnace for vacuum melting, and the melting temperature is 1200 - 1320 °C;

[0013] High-temperature holding: Hold at 1200 - 1320 °C for 5 - 10 minutes;

[0014] Controlled cooling: Obtain the composite material after cooling;

[0015] Post-treatment: Perform heat treatment and machining on the composite material to obtain the finished product.

[0016] In a preferred embodiment, during the controlled cooling process, the temperature gradient is controlled for cooling.

[0017] In a preferred embodiment, the angle of the obtuse angle α is 160° to 175°.

[0018] In a preferred embodiment, tungsten wires are attached to the tungsten rod, which act on the melted copper to generate vibration and combine with the cooled copper.

[0019] In a preferred embodiment, the tungsten wires are arranged in a spiral shape and wound around the tungsten rod.

[0020] In a preferred embodiment, the spiral diameter of the tungsten wire is smaller than the diameter of the tungsten rod.

[0021] In a preferred embodiment, at least 2 copper solder joints are provided on the tungsten wire.

[0022] In a preferred embodiment, the length of the tungsten wire is smaller than the length of the formed copper material.

[0023] In a preferred embodiment, the diameter of the tungsten wire is 0.1 - 0.2 mm.

[0024] A copper-tungsten composite material, comprising a tungsten rod and a copper material, wherein the copper material is coated on the tungsten rod and is made by applying the preparation method of the copper-tungsten composite material described above.

[0025] Compared with the prior art, in the material preparation stage of the present invention, the copper rod and the tungsten rod are degreased, ultrasonically cleaned, and impurities and oxide layers are removed, which effectively ensures the purity of the raw materials, lays a solid foundation for the subsequent preparation of high-quality composite materials, and avoids affecting the welding effect and material properties due to the oil stains, impurities and oxide layers on the surface of the raw materials.

[0026] Furnace charging and vacuum pumping steps: Place the graphite mold with the materials into the vacuum furnace and pump the vacuum furnace to a specific vacuum level. This creates an oxygen-free environment for subsequent vacuum melting, effectively preventing material oxidation during melting, significantly improving the welding quality, and meeting the strict requirements of vacuum brazing for the vacuum environment.

[0027] In the vacuum melting and high-temperature holding stage, heat the vacuum furnace to 1200 - 1320 °C and hold it within this temperature range for 5 - 10 minutes. Precise temperature control and duration control ensure that the copper rod melts completely, providing conditions for high-quality bonding between copper and tungsten, ensuring sufficient copper penetration and avoiding bubble formation.

[0028] After controlled cooling, perform heat treatment and machining on the composite material to obtain the finished product. Through this series of processes, the material properties are further optimized to meet the diverse requirements of actual use.

[0029] The particularly prominent design is as follows: The frustum-shaped design at the bottom of the copper rod enables the molten copper to fall and roll along the surface of the tungsten rod when the copper rod melts. This process can effectively expel the gas adsorbed on the surface of the tungsten rod, avoiding bonding defects caused by bubbles at the copper-tungsten joint after cooling. It greatly improves the bonding quality of the copper-tungsten composite material and breaks through the limitations of the vacuum brazing process in terms of operating conditions and workpiece status. Description of the Drawings

[0030] Figure 1 is a process flow chart of a method for preparing a copper-tungsten composite material according to the present invention.

[0031] Figure 2 is a schematic structural diagram of a copper-tungsten composite material according to the present invention.

[0032] Figure 3 is a schematic diagram showing the placement of the graphite mold and materials used in a method for preparing a copper-tungsten composite material according to the present invention.

[0033] Figure 4 is Figure 3 a longitudinal cross-sectional structural diagram of the structure shown in

[0034] Figure 5 is Figure 4 an enlarged structural diagram of part A in

[0035] Figure 6 is a schematic diagram showing the placement state of the copper rod and the tungsten rod in a method for preparing a copper-tungsten composite material according to the present invention.

[0036] Figure 7 is a schematic structural diagram of the vacuum furnace used in a method for preparing a copper-tungsten composite material according to the present invention.

[0037] Figure 8 It is a schematic diagram of the internal structure of a vacuum furnace applied in a method for preparing a copper-tungsten composite material according to the present invention.

[0038] Copper material 1; copper rod 2; tungsten rod 3; tungsten wire 4; graphite mold 5; forming hole 6; vacuum furnace 7. Specific embodiments

[0039] The present invention will be further described in detail below with reference to the accompanying drawings.

[0040] This specific embodiment is only an explanation of the present invention and is not a limitation thereof. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law. Example 1

[0041] Referring to Figures 1 to 8 , a method for preparing a copper-tungsten composite material includes the steps:

[0042] Material preparation: Take copper rod 2 and tungsten rod 3, and degrease and ultrasonically clean copper rod 2 and tungsten rod 3 to remove impurities and oxide layers;

[0043] Molding: First, place tungsten rod 3 into forming hole 6 of graphite mold 5, and then place copper rod 2 on top of tungsten rod 3. The bottom end of copper rod 2 has a frustum part, and an obtuse angle α is formed between the side surface of the frustum part and the side surface of tungsten rod 3;

[0044] Furnace loading: Send graphite mold 5 with copper rod 2 and tungsten rod 3 placed therein into vacuum furnace 7;

[0045] Vacuum pumping: Pump vacuum for vacuum furnace 7, and the vacuum degree is 10 -3 -10 -5 Pa;

[0046] Vacuum melting: Heat up vacuum furnace 7 for vacuum melting, and the melting temperature is 1200 - 1320 °C;

[0047] High-temperature holding: Hold at 1200 - 1320 °C for 5 - 10 minutes;

[0048] Controlled cooling: Obtain a composite material after cooling;

[0049] Post-treatment: Perform heat treatment and machining on the composite material to obtain the finished product.

[0050] In the material preparation stage of the method for preparing a copper-tungsten composite material in this embodiment, the copper rod 2 and the tungsten rod 3 are degreased, ultrasonically cleaned, and impurities and oxide layers are removed. This effectively ensures the purity of the raw materials, lays a solid foundation for the subsequent preparation of high-quality composite materials, and avoids affecting the welding effect and material properties due to oil stains, impurities, and oxide layers on the surface of the raw materials.

[0051] In the steps of loading into the furnace and evacuating to vacuum, the graphite mold 5 with the materials placed is sent into the vacuum furnace 7, and the vacuum furnace 7 is evacuated to a specific vacuum degree. This creates an oxygen-free environment for the subsequent vacuum melting, effectively avoids oxidation of the materials during the melting process, greatly improves the welding quality, and meets the strict requirements of vacuum brazing for the vacuum environment.

[0052] In the vacuum melting and high-temperature holding stage, the vacuum furnace 7 is heated to 1200 - 1320 °C and held in this temperature range for 5 - 10 minutes. Precise temperature control and duration control ensure that the copper rod 2 is fully melted, provide conditions for achieving high-quality bonding between copper and tungsten, ensure that copper fully penetrates, and avoid the generation of bubbles.

[0053] After controlled cooling, the composite material is subjected to heat treatment and machining to obtain the finished product. Through this series of treatments, the material properties are further optimized to meet the diverse requirements of actual use.

[0054] The particularly prominent design lies in: the frustum-shaped design at the bottom end of the copper rod 2 enables the molten copper to fall and roll along the surface of the tungsten rod 3 when the copper rod 2 melts. This process can effectively expel the gas adsorbed on the surface of the tungsten rod 3, avoid bonding defects caused by bubbles at the copper-tungsten joint after cooling, greatly improve the bonding quality of the copper-tungsten composite material, and break through the limitations of the vacuum brazing process in terms of operating conditions and workpiece status.

[0055] Furthermore, during the controlled cooling process, gradient cooling is controlled. The advantages of gradient cooling are as follows:

[0056] 1. Regulate the microstructure of the material

[0057] The thermophysical properties of copper and tungsten are significantly different, and there are large differences in the thermal expansion coefficients. If the cooling rate is uniform, during the cooling process, due to the inconsistent shrinkage degrees of the two materials, large internal stresses will be generated at the interface, resulting in defects in the microstructure. Gradient cooling can reasonably control the cooling rate according to the characteristics of copper and tungsten at different temperature stages. At the high-temperature stage, the cooling rate is appropriately increased to inhibit the precipitation of harmful phases and refine the grains; at the low-temperature stage, the cooling rate is slowed down to allow sufficient time for the release of internal stresses in the material and promote the full diffusion of atoms, thereby optimizing the microstructure and enhancing the stability of the material.

[0058] 2. Reduce residual stress

[0059] During the cooling process, due to the asynchronous shrinkage of copper and tungsten, residual stress will be formed inside the material. Residual stress not only reduces the fatigue strength of the material but may also cause the material to deform or even crack during subsequent processing or use. Gradient cooling effectively reduces the residual stress inside the material by gradually adjusting the cooling rate, allowing copper and tungsten to shrink orderly at different stages. This reduction in stress significantly improves the reliability of the material, extends its service life in practical applications, and reduces product failures caused by stress problems.

[0060] 3. Improve the bonding strength of the material

[0061] The cooling process has a significant impact on the bonding strength between copper and tungsten. Gradient cooling can form a more stable and continuous metallurgical bond between copper and tungsten at the interface. In the initial stage of cooling, a faster cooling rate promotes the rapid mutual diffusion of copper atoms and tungsten atoms, forming strong chemical bonds. As the temperature decreases, slowing down the cooling rate helps to further improve the interface structure and enhance the interfacial bonding force. This significantly improves the overall bonding strength of the copper-tungsten composite material, meeting the stringent requirements for material properties in the high-end manufacturing field.

[0062] 4. Ensure the consistency of product quality

[0063] In industrial production, the consistency of product quality is crucial. Gradient cooling reduces the material property differences caused by fluctuations in cooling conditions by precisely controlling the cooling process. Whether it is small-batch trial production or large-scale production, it can ensure the quality stability of each copper-tungsten composite material product, improve production efficiency, reduce production costs, and enhance the competitiveness of products in the market.

[0064] In this embodiment, the angle of the obtuse angle α is 160° to 175°. Within this angle range, after the copper rod 2 melts, the path and speed of the copper liquid rolling along the surface of the tungsten rod 3 are more ideal, which is conducive to fully expelling the gas adsorbed on the surface of the tungsten rod 3, greatly reducing the probability of bubble generation at the copper-tungsten joint, and improving the bonding quality. At the same time, this design can effectively reduce the problem of inconvenient coordination between the copper rod 2 and the tungsten rod 3 caused by unreasonable angles.

[0065] To further eliminate the possibility of bubble generation between copper and tungsten, a tungsten wire 4 is attached to the tungsten rod 3, which acts on the melted copper to generate vibrations and combines with the cooled copper. When the copper rod 2 is heated and melted during the vacuum melting stage, the liquid copper flows along the surface of the tungsten rod 3 under the action of gravity. During this process, the copper liquid deflects the tungsten wire 4 attached to the tungsten rod 3. This deflection causes the tungsten wire 4 to vibrate. On the one hand, the vibration makes it easier for bubbles to escape from the system. On the other hand, it promotes the generation of disturbances inside the copper liquid, and the gas originally adsorbed on the surface of the tungsten rod 3 is also released, effectively preventing these gases from forming bubbles and remaining at the copper-tungsten joint during the cooling and solidification process. As the copper liquid cools, the tungsten wire 4 combines with the solidified copper, enhancing the connection strength between copper and tungsten.

[0066] Furthermore, the tungsten wire 4 is arranged in a spiral shape and wound around the tungsten rod 3. The spiral-shaped tungsten wire 4 greatly increases the contact area with the copper liquid and is also conducive to the generation and transmission of vibrations. When the copper rod 2 melts, the copper liquid flowing along the surface of the tungsten rod 3 will exert forces on various parts of the spiral-shaped tungsten wire 4, triggering continuous vibrations. Compared with ordinary settings, this kind of vibration is more uniform and efficient, greatly improving the bubble discharge efficiency and significantly reducing the possibility of bubble residue at the copper-tungsten joint. In terms of the bonding strength, the spiral structure enables the tungsten wire 4 to form a tighter and more solid bond with the cooled copper. During the flow of the copper liquid, it can fully fill the spiral gaps and form an interlocking structure after cooling and solidification, effectively enhancing the mechanical bite and metallurgical bond between copper and tungsten. In addition, the presence of the spiral-shaped tungsten wire 4 guides the flow direction of the copper liquid, making its distribution more uniform and optimizing the tissue and property distribution inside the composite material.

[0067] To enable the tungsten wire 4 to be stably wound around the tungsten rod 3, the spiral diameter of the tungsten wire 4 is smaller than the diameter of the tungsten rod 3, so that the tungsten wire 4 can achieve a tight winding around the tungsten rod 3.

[0068] To further stabilize the tungsten wire 4, at least two copper solder joints are provided on the tungsten wire 4.

[0069] To prevent the tungsten wire 4 from protruding from the copper material 1, the length of the tungsten wire 4 is less than the length of the formed copper material 1.

[0070] In this embodiment, the diameter of the tungsten wire 4 is 0.1 - 0.2 mm. Such a diameter setting is easily deflected by the copper liquid, efficiently eliminates bubbles, ensures the material quality, and can fully combine with copper, enhancing the bonding strength and maintaining the process stability. Embodiment Two

[0071] Refer to Figures 1 to 8 , a copper-tungsten composite material, including a tungsten rod 3 and a copper material 1, wherein the copper material 1 is coated on the tungsten rod 3 and is made by using the preparation method of the copper-tungsten composite material described in Embodiment One.

[0072] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or terminal device. Without further limitation, elements defined by the statement "comprising..." or "including..." do not exclude the existence of additional elements in the process, method, article or terminal device comprising the said elements. In addition, in this text, "greater than", "less than", "more than" are understood not to include the number itself; "above", "below", "within" are understood to include the number itself.

[0073] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the present invention. Those skilled in the art can obviously make various modifications to the embodiments easily and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A preparation method of a copper-tungsten composite material, characterized in that, Including the steps: Stock preparation: Take copper rods and tungsten rods, and degrease and ultrasonically clean the copper rods and tungsten rods to remove impurities and oxide layers; Insert into the mold: First, place the tungsten rod into the forming hole of the graphite mold, and then place the copper rod on top of the tungsten rod. The bottom end of the copper rod has a frustum-shaped part, and an obtuse angle α is formed between the side surface of the frustum-shaped part and the side surface of the tungsten rod. The frustum-shaped design at the bottom end of the copper rod enables the melted copper to fall and roll along the surface of the tungsten rod when the copper rod melts; Insert into the furnace: Send the graphite mold with the copper rod and tungsten rod into the vacuum furnace; Vacuum pumping: Pump the vacuum furnace to a vacuum degree of 10 -3 -10 -5 Pa; Vacuum melting: Heat up the vacuum furnace for vacuum melting, and the melting temperature is 1200 - 1320 °C; High-temperature holding: Hold at 1200 - 1320 °C for 5 - 10 minutes; Controlled cooling: Obtain a composite material after cooling; Post-treatment: Perform heat treatment and machining on the composite material to obtain the finished product.

2. The preparation method of a copper-tungsten composite material according to claim 1, characterized in that, During the controlled cooling process, control the temperature gradient for cooling.

3. The preparation method of a copper-tungsten composite material according to claim 1, characterized in that, The angle of the obtuse angle α is 160° to 175°.

4. The preparation method of a copper-tungsten composite material according to claim 1, wherein, Tungsten wires are attached to the tungsten rod, which act on the melted copper to generate vibrations and combine with the cooled copper.

5. The preparation method of a copper-tungsten composite material according to claim 4, characterized in that, The tungsten wires are arranged in a spiral shape and wound around the tungsten rod.

6. The preparation method of a copper-tungsten composite material according to claim 5, wherein, The spiral diameter of the tungsten wire is smaller than the diameter of the tungsten rod.

7. The preparation method of a copper-tungsten composite material according to claim 5, characterized in that, There are at least 2 copper solder joints on the tungsten wire.

8. The preparation method of a copper-tungsten composite material according to claim 5, wherein The length of the tungsten wire is shorter than the length of the formed copper material.

9. The preparation method of a copper-tungsten composite material according to claim 4, characterized in that, The diameter of the tungsten wire is 0.1 - 0.2 mm.

10. A copper-tungsten composite material, comprising a tungsten rod and copper material, wherein the copper material is coated on the tungsten rod, characterized in that, Prepared by using the preparation method of the copper-tungsten composite material according to any one of claims 1 to 9.

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