Preparation method of energy storage box aluminum alloy water-cooling plate with high qualified rate

Abstract

The invention relates to a high-yield energy storage box aluminum alloy water-cooling plate preparation method which comprises the following steps: cutting a whole aluminum material to obtain a base plate blank and a cover plate blank, and reserving certain margins at the peripheries; the substrate blank and the cover plate blank are cleaned through plasma activation cleaning, and blank impurities are removed; the base plate is placed on a CNC machine tool to be fixed, and a tool bit of the CNC machine tool digs out a main flow channel in the surface of the base plate along a preset path; compressed air is used for blowing away metal chippings in the main runner, then an electrolysis process is adopted, and residual fine burrs of the main runner are accurately removed through anodic dissolution; performing pulse micro-arc oxidation treatment on the surface of the substrate; the inner wall of the main runner is coated with thermoplastic nano-imprinting glue; the water-cooling plate has the advantages that the heat dissipation uniformity of the water-cooling plate is improved, the heat dissipation cooling speed of the water-cooling plate is increased, the strength of the base body is improved, the service life of the water-cooling plate is effectively prolonged, and the high percent of pass during preparation of the water-cooling plate is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of water-cooled plate preparation, and particularly to a method for preparing an aluminum alloy water-cooled plate for an energy storage box with a high qualified rate. Background Art

[0002] With the continuous increase in the power density of electronic devices (such as 5G base stations, high-computing power chips, new energy vehicle electronic control systems, etc.), traditional air-cooled heat dissipation can no longer meet the temperature control requirements of high heat flux density scenarios (>300W / cm 2 )). Liquid cooling technology, with its high thermal conductivity coefficient (the thermal conductivity of water is about 25 times that of air) and uniform heat dissipation characteristics, has become the core solution for the thermal management of high-power devices. As a key heat transfer component of the liquid cooling system, the preparation technology of the water-cooled plate directly determines the heat dissipation efficiency, reliability, and cost.

[0003] Patent No. CN202411723920.6 discloses a method for preparing a PVD semiconductor reaction chamber water-cooled plate assembly and the water-cooled plate assembly, which relates to the technical field of semiconductor water-cooled plate preparation. The method includes: cutting oxygen-free copper material according to the target base size, and then performing rough machining to obtain a base blank; cutting oxygen-free copper material according to the target cover size, and then performing rough machining to obtain a cover blank; heat-treating the cover blank to obtain a heat-treated cover blank; assembling the base blank and the heat-treated cover blank, and then performing welding to obtain an assembled component; performing a water pressure test on the assembled component under a water pressure of 0.6MPa - 0.8MPa; performing finish machining on the assembled component that passes the water pressure test, and then performing helium leak detection to obtain a finished water-cooled plate assembly. The water-cooled plate assembly of the present application can be closely combined with the semiconductor reaction chamber, has a high welding sealing performance, and has a high heat conduction efficiency. Heat can be taken away through water cooling transmission, enabling the semiconductor device to quickly cool down with a high cooling efficiency. However, this process has the following problems: Firstly, when only a main flow channel is provided for cooling in this process, the heat dissipation uniformity is not high. Secondly, the qualified rate of the weld seam cannot be improved when preparing the water-cooled plate by this process. Summary of the Invention

[0004] The object of the present invention is to address the deficiencies of the prior art. By setting micro-channels imprinted on the inner wall of the main flow channel to form a composite flow channel, the main flow channel is responsible for large-flow heat exchange, the micro-channels enhance the water flow turbulence, and the heat dissipation uniformity ability is improved. The total heat dissipation area increases. At the same time, the composite flow channel can increase the water flow velocity at the circular corner, solving the technical problem that the heat dissipation uniformity is not high when only a main flow channel is provided for cooling in this process. When performing welding treatment at the joint by setting friction stir welding, electromagnetic coils are arranged around the stirring head to improve the welding speed, and an infrared thermal imager is used to monitor the weld seam temperature in real time to solve the technical problem that the qualified rate of the weld seam cannot be improved when preparing the water-cooled plate by this process.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A preparation method of an aluminum alloy water-cooled plate for an energy storage box with a high qualified rate, comprising

[0007] Step S1: Cut the whole piece of aluminum material to obtain a substrate blank and a cover plate blank, leaving a certain margin around, and select the most heat-resistant aluminum alloy raw material to ensure the smooth progress of subsequent processes;

[0008] Step S2: Clean the substrate blank and the cover plate blank by plasma-activated cleaning to remove blank impurities;

[0009] Step S3: Place the substrate on a CNC machine tool for fixation, and the cutter head of the CNC machine tool digs out the main flow channel on the surface of the substrate along a preset path;

[0010] Step S4: Use compressed air to blow out the metal chips in the main flow channel, and then adopt an electrolytic process to accurately remove the remaining fine burrs in the main flow channel through anodic dissolution;

[0011] Step S5: Perform pulsed micro-arc oxidation treatment on the surface of the substrate;

[0012] Step S6: Coat the inner wall of the main flow channel with a thermoplastic nanoimprinting adhesive;

[0013] Step S7: Use the imprinting surface of the nanoimprinting template to imprint and form microchannels on the inner wall of the main flow channel;

[0014] Step S8: Place the substrate under ultraviolet light for irradiation to cure the microchannels and form a composite flow channel together with the main flow channel;

[0015] Step S9: Fix the substrate and the cover plate with a tooling fixture, and then use friction stir welding to weld the joint to form the entire water-cooled plate;

[0016] Step S10: Remove the excess height of the weld area by CNC secondary machining milling and perform fly surface shaping;

[0017] Step S11: Sandblast the surface of the water-cooled plate, and then perform gradient temperature aging treatment on the entire water-cooled plate;

[0018] Step S12: Install the inlet and outlet nozzles, connect the pipelines and test the sealing performance;

[0019] Step S13: Conduct quality test inspection on the water-cooled plate.

[0020] According to the preparation method of an aluminum alloy water-cooled plate for an energy storage box with a high qualified rate as described in claim 1, it is characterized in that the imprinting surface of the nanoimprinting template in step S7 is provided with tree-shaped fractal microchannel protrusions, and the size is 20-50 μm.

[0021] As a preference, the imprinting surface of the nanoimprint template in step S7 is provided with dendritic fractal microchannel protrusions, with a size of 20 - 50 μm.

[0022] As a preference, in step S7, the imprinting surface of the nanoimprint template is imprinted on the nanoimprint layer on the inner wall of the main channel at 280 °C and 60 MPa to form a shape, and the pressure holding time is 120 s.

[0023] As a preference, the first stage of the gradient temperature aging treatment in step S11 is the low temperature section of 80 - 120 °C, the second stage is the medium temperature section of 150 - 200 °C, and the third stage is the high temperature section of 250 - 300 °C.

[0024] As a preference, in step S11, the water cooling plate first completes the passivation reaction after sandblasting through the low temperature section, then realizes the crystal form transformation of the passivation layer in the medium temperature section, and finally completes the aging strengthening through the high temperature section.

[0025] As a preference, when performing the welding treatment at the joint in step S9 by friction stir welding, an electromagnetic coil is arranged around the stirring head, with a magnetic field strength of 0.3 T, to increase the welding speed.

[0026] As a preference, when welding the joint in step S9, an infrared thermal imager is used to monitor the weld temperature in real time and control it at 450 - 480 °C.

[0027] As a preference, when performing pulsed micro-arc oxidation treatment on the surface of the substrate in step S5, a voltage of 400 v and a frequency of 1000 Hz are used to generate a ceramic oxide layer with a thickness of 5 - 8 μm. The ceramic oxide layer needs to be polished to form a surface roughness to ensure the adhesion of the nanoimprinting glue.

[0028] As another preference, in step S9, a UV light source with a wavelength of 365 nm is used to ensure complete cross-linking of the nanoimprinting glue, and the curing time is shortened to 10 - 30 seconds.

[0029] Advantages of the present invention:

[0030] (1) In the present invention, by performing pulsed micro-arc oxidation treatment on the surface of the substrate in step S5 to form a ceramic oxide layer, while improving the corrosion resistance of the substrate, the adhesion of the nanoimprinting glue in the subsequent step S7 can be improved. When the microchannel is ultraviolet cured and forms a composite channel together with the main channel, the main channel is responsible for large-flow heat exchange, the microchannel enhances the water flow turbulence, improves the heat dissipation uniformity ability, increases the total heat dissipation area. At the same time, the composite channel can increase the water flow velocity at the circular corner. Under the same flow rate, compared with the traditional single-layer channel, the composite channel reduces the demand for the pump, increases the heat dissipation uniformity of the water cooling plate, and improves the heat dissipation and cooling speed of the water cooling plate.

[0031] (2) In the present invention, by setting the step of performing gradient temperature aging treatment on the water-cooled plate after sandblasting. During the gradient temperature aging treatment, first, the passivation reaction after sandblasting is completed in the low-temperature section of 80 - 120 °C. Subsequently, the crystal form transformation of the passivation layer is achieved in the medium-temperature section of 150 - 200 °C. Finally, age hardening is completed in the high-temperature section of 250 - 300 °C, realizing the integration of processes, synchronously improving the strength of the substrate body and the adhesion of the passivation layer. The micro-pits formed by sandblasting are controlled by gradient temperature, enabling the passivation solution to deeply penetrate during the thermal expansion - contraction cycle, improving the density of the passivation film, and effectively increasing the service life of the water-cooled plate.

[0032] (3) In the present invention, by setting a high-frequency electromagnetic coil integrated around the stirring head and a dynamic pressure feedback system to adjust the downward pressure in real time, while avoiding the collapse of the micro-structure at the weld seam and improving the welding speed. When performing the step S9 at the welding joint, an infrared thermal imager is used to monitor the weld temperature in real time and control it at 450 - 480 °C to prevent thermal damage to the nanoimprint layer. At the same time, in step S2, plasma activation cleaning is used for the substrate blank and the cover plate blank. While removing organic substances such as grease, fingerprints, and dust, it can also use plasma bombardment to form nano-scale concave and convex structures, increasing the mechanical interlocking effect and reducing the rate of false soldering, enabling the improvement of the weld quality when welding the joint in step S8 and ensuring a high qualification rate during the preparation of the water-cooled plate.

[0033] In summary, this process has the advantages of increasing the heat dissipation uniformity of the water-cooled plate, improving the heat dissipation and cooling speed of the water-cooled plate, enhancing the strength of the substrate body, effectively increasing the service life of the water-cooled plate, and ensuring a high qualification rate during the preparation of the water-cooled plate, and is particularly suitable for the technical field of water-cooled plate preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0035] Figure 1 It is a schematic diagram of the overall steps of the present invention.

[0036] Figure 2 It is a schematic diagram of the steps of gradient temperature aging treatment for sandblasting on the surface of the substrate in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the drawings.

[0038] Embodiment 1

[0039] As Figures 1 to 2As shown in the figure, the present invention provides a method for preparing an aluminum alloy water-cooled plate for an energy storage box with a high qualified rate, including

[0040] Step S1: Cut the whole piece of aluminum material to obtain a substrate blank and a cover plate blank, leaving a certain margin around, and the margin is used to compensate for possible dimensional deviations or surface unevenness in the cutting process, providing an adjustment space for subsequent finishing;

[0041] Step S2: Clean the substrate blank and the cover plate blank through plasma-activated cleaning to remove blank impurities and ensure that there is no impurity and moisture residue on the welding surface;

[0042] Step S3: Place the substrate on a CNC machine tool for fixation, and the cutter head of the CNC machine tool digs out the main flow channel on the surface of the substrate along a preset path;

[0043] Step S4: Use compressed air to blow out the metal chips in the main flow channel to ensure that there are no impurities in the main flow channel, and then adopt an electrolytic process to accurately remove the remaining fine burrs on the main flow channel through anodic dissolution, avoiding mechanical contact damage to the surface of the main flow channel;

[0044] Step S5: Perform pulsed micro-arc oxidation treatment on the surface of the substrate to generate an oxidation ceramic layer on the surface of the substrate and the main flow channel;

[0045] Step S6: Coat the inner wall of the main flow channel with a thermoplastic nano-imprinting adhesive;

[0046] Step S7: Use the imprinting surface of the nano-imprinting template to imprint and form micro-channels on the inner wall of the main flow channel;

[0047] Step S8: Place the substrate under ultraviolet light for irradiation to cure the micro-channels and form a composite flow channel together with the main flow channel;

[0048] Step S9: Fix the substrate and the cover plate with a tooling fixture, and then use friction stir welding to weld the joint to form the entire water-cooled plate;

[0049] Step S10: Remove the excess height of the weld area through secondary CNC machining milling and perform fly surface shaping to ensure surface flatness;

[0050] Step S11: Sandblast the surface of the water-cooled plate, and then perform gradient temperature aging treatment on the entire water-cooled plate, and strengthen the surface of the water-cooled plate during the gradient temperature aging treatment;

[0051] Step S12: Install the inlet and outlet nozzles, connect the pipelines and test the sealing performance;

[0052] Step S13: Conduct quality test and inspection of the water-cooled plate.

[0053] Further, the imprinting surface of the nanoimprint template in step S7 is provided with dendritic fractal microchannel protrusions, which are three-dimensional with a fractal dimension of 1.5. The nanoimprint template can be used for a long time. This nanoimprint template has many sizes and templates, which are adapted to different water-cooling plate substrates and main channels. After the main channel is dug out by a CNC machine tool, the protrusions on the imprinting surface of the nanoimprint template are adapted to the main channel. The resin dispensing microchannel protrusions provided on the protrusions where the imprinting surface of the nanoimprint template is adapted to the main channel are the main force for imprinting microchannels, with a size of 20 - 50 μm.

[0054] Further, in step S7, the imprinting surface of the nanoimprint template is imprinted on the nanoimprint layer on the inner wall of the main channel at 280 °C and 60 MPa to form a shape, and the pressure holding time is 120 s.

[0055] Further, the first stage of the gradient temperature aging treatment in step S11 is the low temperature section of 80 - 120 °C, the second stage is the medium temperature section of 150 - 200 °C, and the third stage is the high temperature section of 250 - 300 °C, which can effectively improve the overall strength of the water-cooling plate.

[0056] Further, in step S11, the water-cooling plate first completes the passivation reaction after sandblasting through the low temperature section, then realizes the crystal form transformation of the passivation layer in the medium temperature section, and finally completes the aging strengthening through the high temperature section, realizing the integration of processes, synchronously improving the strength of the substrate body and the adhesion of the passivation layer. The micro-pits formed by sandblasting are controlled by gradient temperature, so that the passivation solution deeply penetrates in the thermal expansion - contraction cycle, improving the density of the passivation film and effectively increasing the service life of the water-cooling plate.

[0057] Further, when welding the joint in step S9 by friction stir welding, electromagnetic coils are arranged around the stirring head. The electromagnetic coils are located at the upper end of the specific operation position of the stirring head, which will not affect the welding operation of the water-cooling plate. The magnetic field strength is 0.3 T. At the same time, an electromagnetic shielding layer is provided at the upper end of the stirring head to improve the welding speed. The dynamic pressure feedback system adjusts the downward pressure in real time, avoiding the collapse of the micro-structure at the weld while improving the welding speed.

[0058] Further, when welding the joint in step S9, an infrared thermal imager is used to monitor the weld temperature in real time, controlling it at 450 - 480 °C to prevent thermal damage to the nanoimprint layer. At the same time, in step S2, plasma activation cleaning is used for the substrate blank and the cover plate blank. While removing organic substances such as grease, fingerprints, and dust, it can also use plasma bombardment to form nano-scale concave and convex structures, increasing the mechanical bite effect and reducing the rate of false soldering, so that the quality of the weld can be improved when welding the joint in step S8, ensuring a high qualification rate during the preparation of the water-cooling plate.

[0059] Further, during the pulse micro-arc oxidation treatment of the substrate surface in step S5, a voltage of 400V and a frequency of 1000Hz are used to generate a ceramic oxide layer with a thickness of 5 - 8μm. The ceramic oxide layer needs to be polished to form a surface roughness to ensure the adhesion of the nanoimprint adhesive. While improving the corrosion resistance of the substrate, it can also enhance the adhesion of the nanoimprint adhesive in subsequent step S7. After the microchannel is cured by ultraviolet light and forms a composite channel together with the main channel, the main channel is responsible for large-flow heat exchange, the microchannel enhances the water flow turbulence, improves the heat dissipation uniformity ability, increases the total heat dissipation area. At the same time, the composite channel can increase the flow velocity of the water at the circular corner. At the same flow rate, the composite channel requires less pump power compared to the traditional single-layer channel, increases the heat dissipation uniformity of the water-cooled plate, and improves the heat dissipation and cooling speed of the water-cooled plate.

[0060] Furthermore, in step S9, a UV light source with a wavelength of 365nm is used to ensure the complete cross-linking of the nanoimprint adhesive, and the curing time is shortened to 10 - 30 seconds.

[0061] Working process: First, the whole aluminum material is cut to obtain the substrate blank and the cover plate blank, with a certain margin left around. The margin is used to compensate for possible dimensional deviations or surface unevenness in the cutting process, providing an adjustment space for subsequent finishing. Then, the substrate blank and the cover plate blank are cleaned by plasma activation cleaning to remove the blank impurities and ensure that there are no impurities and moisture residues on the welding surface. Next, the substrate is placed and fixed on a CNC machine tool. The cutter head of the CNC machine tool digs out the main channel on the substrate surface along the preset path. Immediately, compressed air is used to blow out the metal debris in the main channel to ensure that there are no impurities in the main channel. Then, an electrolytic process is adopted to precisely remove the remaining fine burrs on the main channel surface by anodic dissolution, avoiding mechanical contact damage to the main channel surface. Then, the substrate surface is subjected to pulse micro-arc oxidation treatment to generate an oxide ceramic layer on the substrate and the main channel surface. Next, a thermoplastic nanoimprint adhesive is coated on the inner wall of the main channel. Immediately, the imprinting surface of the nanoimprint template is used to imprint and form the microchannel on the inner wall of the main channel. After the imprinting is completed, the substrate is placed under ultraviolet light for irradiation to cure the microchannel and form a composite channel together with the main channel. After the ultraviolet irradiation is completed, the substrate and the cover plate are fixed by a tooling fixture. Then, friction stir welding is used to weld the joint to form the whole water-cooled plate. Then, the weld area is machined by CNC for a second time to mill off the excess height and perform fly surface shaping to ensure the surface flatness. After the CNC fly surface shaping, the surface of the water-cooled plate is sandblasted. Then, the whole water-cooled plate is subjected to gradient temperature aging treatment, and at the same time, the surface of the water-cooled plate is strengthened during the gradient temperature aging treatment. The inlet and outlet nozzles are installed, the pipelines are connected and the sealing performance is tested. Finally, the quality test and inspection of the water-cooled plate are carried out.

[0062] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "front and back", "left and right", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the invention.

[0063] Of course, in this technical solution, those skilled in the art should understand that the term "one" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of this element can be multiple. The term "one" should not be construed as a limitation to the quantity.

[0064] As described above, it is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement that can be easily thought of by those skilled in the art under the technical inspiration of the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for preparing an aluminum alloy water-cooled plate for an energy storage box with a high qualified rate, characterized in that: include Step S1: Cut the whole piece of aluminum material to obtain a base plate blank and a cover plate blank, leaving a certain margin around them; Step S2: cleaning the substrate blank and the cover plate blank by plasma activation cleaning to remove impurities in the blank; Step S3: The substrate is placed on a CNC machine tool and fixed, and a cutter head of the CNC machine tool digs out a main channel on the surface of the substrate along a preset path; Step S4: using compressed air to blow away metal debris in the main channel, and then using an electrolytic process to accurately remove the remaining fine burrs in the main channel through anodic dissolution; Step S5: performing pulse micro-arc oxidation treatment on the substrate surface; Step S6: coating the inner wall of the main channel with thermoplastic nanoimprint glue; Step S7: using the imprinting surface of the nanoimprint template to imprint and shape the inner wall of the main channel to form a microchannel on the inner wall of the main channel; Step S8: placing the substrate under ultraviolet light to solidify the microchannels and form a composite channel together with the main channel; Step S9: fix the base plate and the cover plate by a fixture, and then use stir friction welding to weld the joints to form the entire water cooling plate; Step S10: The weld area is milled by CNC secondary processing to remove excess height and perform flying surface shaping; Step S11: sandblasting the surface of the water-cooling plate, and then performing gradient temperature aging treatment on the entire water-cooling plate; Step S12: Install the water inlet and outlet nozzles, connect the pipes and test the sealing performance; Step S13: Performing a quality test on the water cooling plate.

2. The method for preparing a high-qualified energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In the step S7, the imprinting surface of the nanoimprint template is provided with tree-like fractal microchannel protrusions with a size of 20-50 μm.

3. The method for preparing a high qualified energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In the step S7, the imprinting surface of the nanoimprint template is imprinted on the nanoimprint layer on the inner wall of the main channel at 280° C. and 60 MPa, and the holding time is 120 seconds.

4. The method for preparing a high qualified rate energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: The first stage of the gradient temperature aging treatment in step S11 is a low temperature stage of 80-120°C, the second stage is a medium temperature stage of 150-200°C, and the third stage is a high temperature stage of 250-300°C.

5. The method for preparing a high qualified rate energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In step S11, the water-cooled plate first passes through a low temperature section to complete the passivation reaction after sandblasting, then realizes the crystal transformation of the passivation layer in a medium temperature section, and finally completes aging strengthening in a high temperature section.

6. The method for preparing a high qualified energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In step S9, when performing the welding process at the joint by friction stir welding, an electromagnetic coil is arranged around the stirring head with a magnetic field strength of 0.3T to increase the welding speed.

7. The method for preparing a high qualified energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In step S9, when welding the joint, an infrared thermal imager is used to monitor the temperature of the weld in real time and control it at 450-480°C.

8. The method for preparing a high qualified rate energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In the step S5, the voltage of 400V and the frequency of 1000Hz are used for pulse micro-arc oxidation treatment on the substrate surface to generate a ceramic oxide layer with a thickness of 5-8μm. The ceramic oxide layer needs to be polished to form surface roughness to ensure the adhesion of the nanoimprint glue.

9. The method for preparing a high qualified energy storage box aluminum alloy water-cooling plate according to claim 1, characterized in that: In the step S8, a UV light source with a wavelength of 365 nm is used to ensure that the nanoimprint adhesive is completely cross-linked and the curing time is shortened to 10-30 seconds.

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