Method for treating molybdenum-copper alloy

Abstract

The embodiment of the invention relates to the technical field of metal matrix surface treatment, in particular to a method for treating molybdenum-copper alloy. The treatment method is used for improving the heat-resistant vacuum volatilization characteristic of the molybdenum-copper alloy and can comprise the steps that the surface of a molybdenum-copper alloy matrix is pretreated to remove surface impurities of the molybdenum-copper alloy matrix; and forming a zirconium layer on the surface of the molybdenum-copper alloy matrix. According to the treatment method provided by the embodiment of the invention, the zirconium layer is formed on the surface of the molybdenum-copper alloy matrix, so that the heat-resistant vacuum volatilization characteristic of the molybdenum-copper alloy is improved, and the failure caused by volatilization of the molybdenum-copper alloy under the high-temperature vacuum condition can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of processing the surface of a metal substrate, and in particular to a method for processing a molybdenum-copper alloy. Background Art

[0002] This section of content merely provides background information related to the present application and does not necessarily constitute prior art.

[0003] Molybdenum-copper alloy is used as a heat transfer material in nuclear power sources for deep space exploration. Its service conditions are usually over 800℃ and less than 1×10 -5 However, the inventors of the present application have found that under such thermal vacuum conditions, the molybdenum-copper alloy material has the problem of failure after serving for a period of time. Summary of the invention

[0004] A brief overview of the present application is provided below in order to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify the key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0005] In response to the above technical problems, an embodiment of the present application provides a method for treating a molybdenum-copper alloy, which is used to improve the heat-resistant vacuum volatilization properties of the molybdenum-copper alloy. The treatment method may include: pretreating the surface of the molybdenum-copper alloy substrate to remove surface impurities of the molybdenum-copper alloy substrate; and forming a zirconium layer on the surface of the molybdenum-copper alloy substrate.

[0006] The treatment method provided in the embodiment of the present application improves the heat-resistant vacuum volatilization properties of the molybdenum-copper alloy by forming a zirconium layer on the surface of the molybdenum-copper alloy substrate, thereby effectively reducing the failure of the molybdenum-copper alloy caused by volatilization under high-temperature vacuum conditions.

[0007] These and other advantages of the present application will become more apparent through the following detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to further illustrate the above and other advantages and features of the present application, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. The accompanying drawings together with the following detailed description are included in this specification and form a part of this specification. Elements with the same function and structure are represented by the same reference numerals. It should be understood that these drawings only describe typical examples of the present application and should not be regarded as limiting the scope of the present application.

[0009] Figure 1is a schematic structural diagram of a sample fixture according to an embodiment of the present application;

[0010] Figure 2 is Figure 1 A schematic diagram of the structure of a molybdenum-copper alloy substrate with an arc segment placed on a sample fixture shown;

[0011] Figure 3 is a schematic structural diagram of a sample fixture according to another embodiment of the present application, wherein a plurality of special-shaped molybdenum-copper alloy substrates are placed on the sample fixture;

[0012] Figure 4 From another perspective Figure 3 A schematic diagram of the structure of the sample fixture shown;

[0013] Figure 5 yes Figure 3 A top view of the sample fixture shown;

[0014] Figure 6 yes Figure 5 The schematic cross-sectional view of the sample fixture along the BB direction is shown;

[0015] Figure 7 yes Figure 3 a bottom view of the sample fixture shown;

[0016] Figure 8 yes Figure 3 A schematic cross-sectional view of the sample fixture shown;

[0017] Fig. 9 is Figure 3 The schematic diagram of the structure of a baffle plate arranged on the surface of a special-shaped molybdenum-copper alloy substrate is shown.

[0018] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding.

[0019] Description of reference numerals:

[0020] 10. Sample fixture;

[0021] 11. Middle connecting piece; 12. End connecting piece;

[0022] 14. Sample mounting part; 141. Rod; 1411. Positioning part; 142. Thrust bearing;

[0023] 1421, bearing bushing; 143, bushing;

[0024] 15. Rotating mating part; 16. Synchronous pulley; 17. Synchronous belt;

[0025] 18. Open your mouth;

[0026] 19. Baffle;

[0027] 100. Molybdenum-copper alloy matrix. DETAILED DESCRIPTION

[0028] Exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the content of this application.

[0029] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

[0030] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should have the common meanings understood by persons with ordinary skills in the field to which this application belongs.

[0031] In the description of the embodiments of the present application, “plurality” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0032] The inventor of the present application found that in the related art, the main reason why the molybdenum-copper alloy fails after a period of service under thermal vacuum conditions is that molybdenum-copper is a pseudo alloy, and copper is easy to volatilize due to its low melting point. Although molybdenum is difficult to volatilize due to its high melting point, it cannot inhibit the volatilization of copper. This causes the copper component of the molybdenum-copper alloy to continuously volatilize under high temperature and high vacuum conditions, thereby causing the molybdenum-copper alloy material to fail.

[0033] The inventor of the present application has found that the zirconium layer can improve the heat-resistant vacuum volatilization characteristics of the molybdenum-copper alloy. Therefore, in order to solve the above technical problems, the embodiment of the present application provides a method for treating the molybdenum-copper alloy, the treatment method is used to improve the heat-resistant vacuum volatilization characteristics of the molybdenum-copper alloy, the treatment method may include: pre-treating the surface of the molybdenum-copper alloy substrate to remove surface impurities of the molybdenum-copper alloy substrate; forming a zirconium layer on the surface of the molybdenum-copper alloy substrate.

[0034] The treatment method provided in the embodiment of the present application forms a zirconium layer on the surface of the molybdenum-copper alloy substrate. Since the zirconium layer has excellent heat-resistant vacuum volatilization properties and still has a low saturated vapor pressure at a high temperature of 800°C, the heat-resistant vacuum volatilization properties of the molybdenum-copper alloy can be improved, thereby extending its service life in a high-temperature and high-vacuum environment and avoiding material failure due to volatilization.

[0035] Furthermore, the inventors of the present application have found that for samples in which the zirconium layer is directly bonded to the surface of the molybdenum-copper alloy, when the molybdenum-copper alloy is in a high temperature environment (e.g., a high temperature environment formed during welding), zirconium will undergo solid solution diffusion with the molybdenum-copper alloy. In order to prevent this situation from occurring, in some embodiments, before forming the zirconium layer, the processing method of the embodiment of the present application may further include: forming an anti-solid solution diffusion layer on the surface of the molybdenum-copper alloy substrate to prevent solid solution diffusion between zirconium and the molybdenum-copper alloy substrate; and forming a zirconium layer on the surface of the anti-solid solution diffusion layer.

[0036] The embodiments of the present application can avoid the solid solution diffusion of zirconium and the molybdenum-copper alloy by providing an anti-solution diffusion layer between the zirconium layer and the molybdenum-copper alloy substrate, thereby ensuring the heat-resistant vacuum volatilization property of the molybdenum-copper alloy.

[0037] The inventors of the present application have also found that the molybdenum layer can improve the thermal stability of the molybdenum-copper alloy substrate and can also improve the bonding force between the zirconium layer and the molybdenum-copper alloy substrate. Therefore, in some embodiments, the solid solution diffusion prevention layer can be a molybdenum layer.

[0038] In some embodiments, the processing method of the embodiment of the present application can use a multi-arc ion plating device to plate an anti-solid solution diffusion layer on the surface of the molybdenum-copper alloy substrate, and plate a zirconium layer on the surface of the anti-solid solution diffusion layer. The multi-arc ion plating device may include a vacuum chamber. The processing method of the embodiment of the present application may include: S1, preparing a zirconium target, a molybdenum target and an etching target; S2, placing the molybdenum-copper alloy substrate, the zirconium target, the molybdenum target, and the etching target into a vacuum chamber, and evacuating the vacuum chamber; S3, etching and cleaning the molybdenum-copper alloy substrate using the etching target; S4, forming a molybdenum layer on the molybdenum-copper alloy substrate using the molybdenum target; S5, forming a zirconium layer on the molybdenum layer using the zirconium target. It is easy to understand that in the process of film coating using a multi-arc ion plating device, molybdenum atoms or zirconium atoms evaporate from the surface of the molybdenum target or the zirconium target under the action of high-energy arc plasma, and are deposited on the surface of the molybdenum-copper alloy substrate to form a molybdenum layer or a zirconium layer. In this embodiment, a molybdenum layer for preventing solid solution diffusion is first plated on the molybdenum-copper alloy through a multi-arc ion plating device, and then a zirconium layer is plated on the molybdenum layer. This can effectively improve the heat-resistant vacuum volatilization characteristics of the molybdenum-copper alloy, while ensuring good bonding between the zirconium layer and the molybdenum-copper alloy substrate.

[0039] Etching and cleaning treatment refers to the removal of impurities on the surface of the substrate by a high-energy ion beam generated by a target. Before coating, the molybdenum-copper alloy substrate is first etched and cleaned using an etching target to further ensure that the molybdenum-copper alloy substrate is free of impurities. In addition, the coating plated by the multi-arc ion plating device has small grains and uniform grain distribution. In a high-temperature vacuum environment, the atomic diffusion at the grain boundaries of the coating is thermally activated, which may cause volatilization, but the possibility of such volatilization is reduced due to the small number of grain boundaries and small grain size.

[0040] In some embodiments, the purity of the molybdenum target and the zirconium target is greater than 99.99%, which is beneficial to improving the heat-resistant vacuum volatilization characteristics of the molybdenum-copper alloy and the bonding strength between the zirconium layer and the molybdenum-copper alloy substrate.

[0041] In some embodiments, in the step of evacuating the vacuum chamber, the vacuum degree in the vacuum chamber can be reduced to below 40 Pa using a pre-evacuation pump and a Roots pump, and then the vacuum degree can be further reduced to 5×10 -5 Pa or less to ensure a high vacuum environment in the vacuum chamber, thereby effectively avoiding the interference of gases on the coating process and improving the purity and quality of the molybdenum layer and the zirconium layer.

[0042] In some embodiments, after the step of evacuating the vacuum chamber, the heating temperature may be set to 190-210° C., and when the temperature reaches the heating temperature, the temperature may be kept constant for 25-35 minutes.

[0043] In some embodiments, before etching and cleaning, 165-175 sccm of argon gas may be introduced to maintain the pressure in the vacuum chamber at 0.15 Pa-0.25 Pa, and then etching and cleaning may be performed. This is beneficial to improving the etching and cleaning effect and ensuring the activity of the surface of the molybdenum-copper alloy substrate.

[0044] In some embodiments, during the etching and cleaning process, the current of the etching target can be 130 to 140A, the negative bias voltage of the molybdenum-copper alloy substrate can be -140 to -160V, and the cleaning time can be 55 to 65 minutes, which is beneficial to improve the etching and cleaning effect and protect the surface of the molybdenum-copper alloy substrate while ensuring the removal of impurities.

[0045] In some embodiments, the etching target material may be a titanium target. The titanium target has moderate activity and can generate a sufficient number of ions during the etching process, while not damaging the surface of the molybdenum-copper alloy substrate due to excessive etching. Therefore, a titanium target is used as the etching target material in this embodiment.

[0046] In some embodiments, the multi-arc ion plating device may further include a rotating platform disposed in the vacuum chamber. The processing method of the embodiment of the present application may further include: providing a sample fixture, placing a plurality of molybdenum-copper alloy substrates on the sample fixture; placing the sample fixture on the rotating platform, and during the coating process, rotating the sample fixture and the rotating platform together, so that the plurality of molybdenum-copper alloy substrates can be coated simultaneously, and uniform coating is facilitated.

[0047] In some embodiments, the multi-arc ion plating device may further include a driving member and a plurality of rotating members disposed on the rotating platform. The plurality of rotating members are distributed along the circumferential direction of the rotating platform. The driving member is used to drive the rotating members to rotate.

[0048] See also Figure 1 and Figure 2 , Figure 1 is a schematic structural diagram of a sample fixture according to an embodiment of the present application; Figure 2 is Figure 1 A schematic diagram of the structure of a molybdenum-copper alloy substrate with an arc segment placed on the sample fixture shown. In some embodiments, the sample fixture 10 may include a middle connector 11, two end connectors 12, a plurality of sample mounting members 14, and a rotating fitting member. The two end connectors 12 are connected to the middle connector 11. Each sample mounting member 14 is used to mount a plurality of molybdenum-copper alloy substrates 100. The two ends of the plurality of sample mounting members 14 are rotatably connected to the two end connectors 12, respectively. The rotating fitting member is connected to the middle connector 11, and the rotating fitting member cooperates with the rotating member, so that the rotating fitting member, the middle connector 11, and the two end connectors 12 are driven by the rotating member to rotate together.

[0049] The multi-arc ion plating device includes a plurality of rotating parts arranged on a rotating platform, each rotating part drives a sample fixture 10 to rotate. Since the sample fixture 10 includes a plurality of sample mounting parts 14, and each sample mounting part 14 can be installed with a plurality of molybdenum-copper alloy substrates 100, a plurality of molybdenum-copper alloy substrates 100 can be plated at the same time, thereby improving the plating efficiency.

[0050] In some embodiments, the multi-arc ion plating device includes 6 rotating parts arranged on a rotating platform, each sample holder 10 may include 5 to 10 sample mounting parts 14, and each sample mounting part 14 can be installed with 6 molybdenum-copper alloy substrates 100, that is, in one coating process, more than 100 molybdenum-copper alloy substrates 100 can be coated at the same time, thereby improving the coating efficiency.

[0051] See also Figure 1 and Figure 2In some embodiments, the sample mounting member 14 may further include a rod 141 and a plurality of positioning member groups disposed on the rod 141. Each positioning member group may include two positioning members 1411 disposed opposite to each other, and two fasteners respectively pass through the two positioning members 1411 of each positioning member group to press the upper and lower ends of the molybdenum-copper alloy substrate 100 tightly, so as to prevent the molybdenum-copper alloy substrate 100 from shaking during the coating process, and at the same time avoid blocking the coating area of ​​the molybdenum-copper alloy substrate 100, which is conducive to improving the uniformity of the coating.

[0052] The molybdenum-copper alloy in the embodiment of the present application can come from the heat pipe structure of the nuclear energy system. In some embodiments, the heat pipe structure is a standard round tube, and when the sample holder 10 of the embodiment of the present application is used to clamp the sample, the shape of the molybdenum-copper alloy substrate 100 can be set to a semicircular arc segment.

[0053] exist Figure 1 and Figure 2 In the illustrated embodiment, the molybdenum-copper alloy substrate 100 is a semicircular arc segment. In such an embodiment, the rod 141 is a cylindrical structure, and the molybdenum-copper alloy substrate 100 of the semicircular arc segment is pressed against the rod 141. The molybdenum-copper alloy substrate 100 of the two semicircular arc segments can be pressed against the rod 141 on both radial sides of the rod 141.

[0054] In some embodiments, the molybdenum copper alloy is derived from a shaped structure used to connect two pipes. Figure 3 , Figure 4 as well as Figure 8 , Figure 3 is a schematic structural diagram of a sample fixture according to another embodiment of the present application, wherein a plurality of special-shaped molybdenum-copper alloy substrates are placed on the sample fixture; Figure 4 From another perspective Figure 3 A schematic diagram of the structure of the sample fixture shown; Figure 8 yes Figure 3 Schematic cross-sectional view of the sample fixture shown. In such an embodiment, the molybdenum-copper alloy substrate 100 can be formed by cutting semicircular arcs inwardly at the upper and lower bases of a structural member with an isosceles trapezoidal cross section. One semicircular arc of the molybdenum-copper alloy substrate 100 with a special-shaped structure is pressed against the rod 141, and the other semicircular arc faces away from the rod 141. The two molybdenum-copper alloy substrates 100 with special-shaped structures can be pressed against the rod 141 on both radial sides of the rod 141.

[0055] See also Fig. 9 , Fig. 9 is Figure 3The schematic diagram of the structure of the baffle plate provided on the surface of the special-shaped molybdenum-copper alloy substrate is shown. Since the semicircular arc facing away from the rod 141 does not need to be coated, a semicircular arc-shaped baffle plate 19 can be provided to shield it. In such an embodiment, the baffle plate 19 can be connected to the positioning member 1411 by fasteners, and there is no need to use fasteners to abut the molybdenum-copper alloy substrate 100, which can reduce damage to the molybdenum-copper alloy substrate 100.

[0056] In some embodiments, each sample mounting member 14 cooperates with the rotating fitting member 15, so that the rotating fitting member 15 drives the sample mounting member 14 to rotate. In this embodiment, the driving member drives the rotating member to rotate, and then the rotating fitting member 15 cooperates with the rotating member to drive the sample fixture 10 to rotate as a whole, so that the molybdenum-copper alloy substrate 100 can be bombarded by the ion beam in a comprehensive and uniform manner during the coating process, thereby improving the uniformity of the coating, ensuring the uniform coverage of the coating on the surface of the molybdenum-copper alloy substrate 100, and effectively avoiding the situation of local uneven thickness.

[0057] See also Figures 5 to 7 , Figure 5 yes Figure 3 A top view of the sample fixture shown; Figure 6 yes Figure 5 The schematic cross-sectional view of the sample fixture along the BB direction is shown; Figure 7 yes Figure 3 A bottom view of the sample holder shown in FIG. 1 is shown in FIG. 1 . In some embodiments, the rotating member and the rotating matching member 15 are two gears meshing with each other. The sample holder 10 may also include a plurality of synchronous pulleys 16 and a plurality of synchronous belts 17. The rotating matching member 15 and the sample mounting member 14 are matched by the plurality of synchronous pulleys 16 and the plurality of synchronous belts 17. With such a configuration, each sample mounting member 14 can be rotated synchronously and at the same speed, thereby achieving uniform coating.

[0058] Two synchronous pulleys 16 are arranged at one end of the rod 141 of the sample mounting member 14. The two synchronous pulleys 16 are coaxial with the rod 141 and can rotate synchronously. A synchronous pulley 16 is arranged at the end of the middle connecting member 11. The synchronous pulley 16 is coaxially arranged with the rotating matching member 15 and can rotate synchronously with the rotating matching member 15. Specifically, the first sample mounting member 14, the second sample mounting member 14, the third sample mounting member 14, ... the nth sample mounting member 14 are sequentially distributed along the circumferential direction. A synchronous pulley 16 of the first sample mounting member 14 is connected to the synchronous pulley 16 of the middle connecting member 11 through a synchronous belt 17, another synchronous pulley 16 of the first sample mounting member 14 is connected to a synchronous pulley 16 of the second sample mounting member 14 through a synchronous belt 17, another synchronous pulley 16 of the second sample mounting member 14 is connected to the synchronous pulley 16 of the third sample mounting member 14 through a synchronous belt 17, another synchronous pulley 16 of the third sample mounting member 14 is connected to a synchronous pulley 16 of the fourth sample mounting member 14 through a synchronous belt 17, and so on, until a synchronous pulley 16 of the nth sample mounting member 14 is connected to a synchronous pulley 16 of the n-1th sample mounting member 14 through a synchronous belt 17.

[0059] In some embodiments, the rotating fitting 15 can be disposed on a side of one end connector 12 facing away from the other end connector 12, so as to cooperate with the rotating member of the rotating platform of the multi-arc ion plating device. For ease of description, the end connector 12 on one side facing the rotating platform of the multi-arc ion plating device is referred to as the first end connector 12, and the other end connector 12 is referred to as the second end connector 12.

[0060] The middle connecting member 11 passes through the first end connecting member 12 and is connected to the rotating fitting member 15 .

[0061] The synchronous pulley 16 can also be arranged on the side of the first end connecting member 12 facing the rotating platform of the multi-arc ion plating device. In such an embodiment, the rod 141 of the sample mounting member 14 passes through the first end connecting member 12 and is connected to the synchronous pulley 16.

[0062] See also Figure 6 In order to reduce the friction between the rod 141 and the first end connector 12 during the rotation process and improve the rotation efficiency, in some embodiments, the sample mounting member 14 may further include a thrust bearing 142, which is disposed at the connection between the rod 141 and the first end connector 12. This arrangement enables the rod 141 to rotate more smoothly, effectively reducing friction and wear. The thrust bearing 142 is sleeved on the radial outer side of the rod 141 and may be disposed on the side of the first end connector 12 that is away from the rotating platform of the multi-arc ion plating device.

[0063] In some embodiments, the thrust bearing 142 may be made of a high temperature resistant material and may withstand a temperature of up to 600° C.

[0064] See also Figure 6 In some embodiments, the sample mounting member 14 may further include a bearing bushing 1421, which is disposed between the rod 141 and the thrust bearing 142 and between the rod 141 and the first end connector 12, so as to facilitate the installation of the thrust bearing 142 and ensure the concentricity of the rod 141, thereby improving the installation efficiency and coating quality of the bearing.

[0065] See also Figure 6 In some embodiments, the sample mount 14 may further include a bushing 143, which is disposed at the connection between the rod 141 and the second end connector 12. The bushing 143 is disposed radially outward of the rod 141 to ensure the stability of the rod 141 and prevent the rod 141 from shaking when rotating, thereby improving the uniformity of the coating.

[0066] In some embodiments, a plurality of openings 18 are relatively provided on the surface of the end connector 12 along the same circumference, so that the end connector 12 forms a hollow structure, which is beneficial to improve the uniformity and efficiency of the coating.

[0067] In some embodiments, the process parameters for forming a molybdenum layer on a molybdenum-copper alloy substrate 100 using a molybdenum target are as follows: the duty cycle of the pulse period can be 45-55%, the rotation speed of the rotating platform can be 1-3r / min, the arc current can be 90-110A, the substrate negative bias voltage of the molybdenum-copper alloy substrate 100 can be -70-80V, the nitrogen flow rate can be 300sccm, and the deposition time can be 85-95min. The process parameters for forming a zirconium layer on a molybdenum layer using a zirconium target are as follows: the duty cycle of the pulse period, the rotation speed of the rotating platform, the nitrogen flow rate and the deposition time are the same as the corresponding parameters for forming the molybdenum layer, the arc current can be 140-160A, and the substrate negative bias voltage of the molybdenum layer can be -65-55V. It is easy to understand that each pulse period can be divided into two stages: "occupy" and "empty", and the duty cycle refers to the time ratio occupied by the effective signal time. Using the above process parameters, the uniformity of the molybdenum layer and the zirconium layer can be improved, the surface damage to the molybdenum-copper alloy substrate 100 can be reduced, and the bonding strength between the molybdenum layer and the zirconium layer can be enhanced.

[0068] In some embodiments, the processing method of the embodiment of the present application may further include performing vacuum heat treatment on the molybdenum-copper alloy substrate 100 after forming the zirconium layer to improve the bonding strength and thermal shock resistance of the coating.

[0069] In some embodiments, the vacuum heat treatment step may include placing the plated molybdenum-copper alloy substrate 100 in a vacuum muffle furnace and evacuating the vacuum to 2×10 -2Pa, then heated to 1000-1200℃ and annealed for 8-12 hours, and finally cooled to room temperature with the furnace to improve the bonding strength and thermal shock resistance of the coating.

[0070] In some embodiments, the step of pre-treating the surface of the molybdenum-copper alloy substrate 100 may include: S01, sandblasting the surface of the molybdenum-copper alloy substrate 100. Sandblasting can remove impurities on the surface of the molybdenum-copper alloy substrate 100, so that the surface is in a compressive stress state, and form a laminated structure that is inlaid and interlocked with each other. The specific operation steps of sandblasting are: select aluminum oxide sand with a particle size range of 200 to 500 mesh as abrasive, apply high pressure through compressed air, transport it to the nozzle through a pipeline and instantly spray it onto the surface of the molybdenum-copper alloy substrate 100 to be plated, and the micro-blade structure of the sand can produce a cutting effect on the surface of the molybdenum-copper alloy substrate 100, thereby effectively removing impurities and adsorbed oxide films on the surface of the molybdenum-copper alloy substrate 100, and increasing the bonding area between the coating and the surface of the molybdenum-copper alloy substrate 100.

[0071] In some embodiments, after the sandblasting step, the step of pre-treating the surface of the molybdenum-copper alloy substrate 100 may include: S02, soaking the surface of the molybdenum-copper alloy substrate 100 in chemical agents and ultrasonic cleaning. The surface of the molybdenum-copper alloy substrate 100 can be cleaned using a special oily cleaning agent and ultrasonic cavitation to remove oily impurities on its surface; then, deionized water can be used as a rinse liquid to rinse the surface of the molybdenum-copper alloy substrate 100, and the rinsing time can be 10 to 20 minutes to avoid impurities and pollutants in the tap water remaining on the surface of the molybdenum-copper alloy substrate 100; then, the molybdenum-copper alloy substrate 100 can be baked to ensure that the molybdenum-copper alloy can remain dry before coating. The baking temperature can be 110 to 130°C, so as to ensure that the water evaporates quickly and dries the molybdenum-copper alloy substrate 100, and to avoid damage to the molybdenum-copper alloy substrate 100 due to excessive temperature, such as deformation, cracking, etc.

[0072] The method for treating the molybdenum-copper alloy in the embodiments of the present application is further explained below with specific examples.

[0073] (1) Pretreatment: First, the surface of the molybdenum-copper alloy substrate 100 is sandblasted and roughened. Alumina sand of 400 mesh is used. Under the high pressure of compressed air, it is instantly sprayed onto the surface of the workpiece to be plated through a pipe and a nozzle for 5 minutes to remove surface impurities of the molybdenum-copper alloy substrate 100 and form a laminated structure in a compressive stress state. Then, a special degreasing cleaning agent is used in combination with ultrasonic cavitation for cleaning for 10 minutes to remove greasy impurities on the surface of the molybdenum-copper alloy substrate 100. Subsequently, deionized water is used for rinsing for 15 minutes to avoid impurities in tap water remaining on the surface of the molybdenum-copper alloy substrate 100. Finally, the molybdenum-copper alloy substrate 100 is baked at a baking temperature of 120°C.

[0074] (2) Fixture preparation and substrate installation: First, prepare a sample fixture 10 made of stainless steel, which includes 6 sample mounting parts 14, each of which can mount 20 substrates. Then, mount the pre-treated molybdenum-copper alloy substrate 100 on the sample mounting parts 14 to ensure that the installation is firm and reliable.

[0075] (3) Preparation of multi-arc ion plating device: prepare zirconium targets, molybdenum targets and etched titanium targets with a purity greater than 99.99%, and place these targets together with the sample holder 10 loaded with the molybdenum-copper alloy substrate 100 into the vacuum chamber of the multi-arc ion plating device. Then, place the sample holder 10 on the rotating platform of the multi-arc ion plating device, and make precise adjustments to ensure that all molybdenum-copper alloy substrates 100 are in the best position for coating. Next, perform the vacuum operation. First, use the pre-pump and Roots pump to evacuate the vacuum chamber to 30Pa, then turn on the turbomolecular pump to further evacuate the vacuum to 3×10 -5 Pa to ensure that the coating process is carried out in a high vacuum environment.

[0076] (4) Pre-treatment of coating: The heating temperature is set to 200°C and maintained at a constant temperature for 30 minutes to ensure that the temperature of the molybdenum-copper alloy substrate 100 is uniform. Subsequently, 170 sccm of argon gas is introduced, the pressure in the chamber is maintained at 0.2 Pa, the titanium target is turned on, the etching titanium target current is set to 135A, the negative bias voltage of the molybdenum-copper alloy substrate 100 is -150V, and etching and cleaning are performed for 60 minutes to further remove impurities on the surface of the molybdenum-copper alloy substrate 100 and prepare for coating treatment.

[0077] (5) Coating treatment: First, the molybdenum target is turned on, and a molybdenum layer that prevents solid solution diffusion is formed on the surface of the molybdenum-copper alloy substrate 100 by using the molybdenum target, and the duty cycle of the pulse cycle is set to 50%, the rotation speed of the rotating platform is 2r / min, the arc current is 100A, the negative bias voltage of the molybdenum-copper alloy substrate 100 is -75V, the nitrogen flow rate is 300sccm, and the deposition time is 90 minutes to ensure that the molybdenum layer is evenly and densely covered on the substrate surface. Then, the molybdenum target is turned off, and the zirconium target is turned on, and a zirconium layer is formed on the molybdenum layer by using the zirconium target, and the duty cycle of the pulse cycle is set to 50%, the rotation speed of the rotating platform is 2r / min, the arc current is 150A, the substrate negative bias voltage of the molybdenum layer is -60V, the nitrogen flow rate is 300sccm, and the deposition time is 90 minutes to ensure that the zirconium layer can be evenly and densely covered on the molybdenum layer.

[0078] (6) Cooling and taking out: After the coating is completed, the coating is cooled with the furnace to prevent stress or defects in the coating layer due to rapid cooling. After cooling to room temperature, the vacuum chamber is opened and the coated molybdenum-copper alloy substrate 100 is taken out.

[0079] (7) Vacuum heat treatment: The coated molybdenum-copper alloy substrate 100 is placed in a vacuum muffle furnace and first evacuated to 1×10 -2 Pa, then heated to 1100 ° C, followed by 10 hours of annealing to improve the bonding strength and thermal shock resistance of the coating. After annealing, it is cooled to room temperature with the furnace.

[0080] The method for processing the molybdenum-copper alloy provided in the embodiment of the present application can sequentially form a molybdenum layer and a zirconium layer of a certain thickness on the surface of the molybdenum-copper alloy substrate 100. The molybdenum layer can improve the thermal stability of the molybdenum-copper alloy material, and the zirconium layer can improve the heat-resistant vacuum volatilization characteristics of the molybdenum-copper alloy material. At the same time, the molybdenum layer and the zirconium layer have similar thermal expansion coefficients to the molybdenum-copper alloy, and can also improve the thermal shock resistance of the molybdenum-copper alloy material, which has good application prospects in the application of heat pipe materials in nuclear energy systems.

[0081] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0082] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for treating a molybdenum-copper alloy, the method being used to improve the heat-resistant vacuum volatilization characteristics of the molybdenum-copper alloy, characterized in that: The method comprises: Pre-treating the surface of the molybdenum-copper alloy substrate to remove surface impurities of the molybdenum-copper alloy substrate; A zirconium layer is formed on the surface of the molybdenum-copper alloy substrate.

2. The method according to claim 1, characterized in that Before forming the zirconium layer, the method further comprises: Forming a solid solution diffusion prevention layer on the surface of the molybdenum-copper alloy substrate to prevent solid solution diffusion between zirconium and the molybdenum-copper alloy substrate; The zirconium layer is formed on the surface of the solid solution diffusion prevention layer.

3. The method according to claim 2, characterized in that The solid solution diffusion prevention layer is a molybdenum layer.

4. The method according to claim 3, characterized in that The method uses a multi-arc ion plating device to plate the anti-solid solution diffusion layer on the surface of the molybdenum-copper alloy substrate, and plates the zirconium layer on the surface of the anti-solid solution diffusion layer, wherein the multi-arc ion plating device includes a vacuum chamber; the method includes: Preparation of zirconium targets, molybdenum targets and etching targets; Putting the molybdenum-copper alloy substrate, the zirconium target, the molybdenum target, and the etching target into the vacuum chamber, and evacuating the vacuum chamber; Using the etching target material to etch and clean the molybdenum-copper alloy substrate; forming the molybdenum layer on the molybdenum-copper alloy substrate by using the molybdenum target; The zirconium layer is formed on the molybdenum layer using the zirconium target.

5. The method according to claim 4, characterized in that The etching target material is a titanium target.

6. The method according to claim 4, characterized in that The multi-arc ion plating device also includes a rotating platform disposed in the vacuum chamber; The method further comprises: Providing a sample fixture, placing a plurality of the molybdenum-copper alloy substrates on the sample fixture; The sample holder is placed on the rotating platform, and during the coating process, the sample holder and the rotating platform are rotated together.

7. The method according to claim 6, characterized in that The multi-arc ion plating device further comprises a driving member and a plurality of rotating members arranged on the rotating platform, wherein the plurality of rotating members are distributed along the circumferential direction of the rotating platform, and the driving member drives the rotating members to rotate; The sample holder comprises: A middle connecting piece and two end connecting pieces, wherein the two end connecting pieces are connected to the middle connecting piece; A plurality of sample mounting parts, each of which is used to mount a plurality of the molybdenum-copper alloy substrates, and both ends of the plurality of sample mounting parts are rotatably connected to the two end connectors respectively; A rotating fitting part connected to the middle connecting part, wherein the rotating fitting part cooperates with the rotating part, so that the rotating fitting part, the middle connecting part and the two end connecting parts are driven by the rotating part to rotate together; Each of the sample mounting parts cooperates with the rotational fitting part, so that the sample mounting part is driven to rotate by the rotational fitting part.

8. The method according to claim 7, characterized in that The rotating member and the rotating matching member are two gears meshing with each other; The sample fixture further comprises: a plurality of synchronous pulleys and a plurality of synchronous belts, and the rotating fittings and the plurality of sample mounting parts are matched with each other through the plurality of synchronous pulleys and the plurality of synchronous belts.

9. The method according to claim 6, characterized in that The process parameters for forming the molybdenum layer on the molybdenum-copper alloy substrate using the molybdenum target are as follows: The duty cycle of the pulse period is 45-55%, the rotation speed of the rotating platform is 1-3 r / min, the arc current is 90-110 A, the substrate negative bias voltage of the molybdenum-copper alloy substrate is -70--80 V, the nitrogen flow rate is 300 sccm, and the deposition time is 85-95 min; The process parameters for forming the zirconium layer on the molybdenum layer using the zirconium target are as follows: The duty cycle of the pulse period, the rotation speed of the rotating platform, the nitrogen flow rate and the deposition time are respectively the same as the corresponding parameters for forming the molybdenum layer, the arc current is 140 to 160A, and the negative bias voltage of the substrate of the molybdenum layer is -65 to -55V.

10. The method according to claim 2, characterized in that Also includes: After the zirconium layer is formed, the molybdenum-copper alloy substrate is subjected to vacuum heat treatment.

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