A manufacturing process for microchannel structure flat plates

Abstract

This invention belongs to the field of electron beam welding technology and provides a manufacturing process for a microchannel structure plate. The process includes machining channels on the top surface of a raw material plate to obtain a channel plate; mounting a cover plate on the top surface of the channel plate to cover it; pressing the cover plate perpendicular to the channel plate until slight plastic deformation occurs, causing the bottom surface of the cover plate to fit against the top surface of the ribs and revealing the positions of the ribs on the cover plate; electron beam welding the cover plate and ribs at the revealed rib positions; and finally removing the frame to obtain the microchannel structure plate. The pressing process of this invention is performed at room temperature, preventing deformation of the ribs on the base plate due to high temperature and pressure. Furthermore, since electron beam welding is performed directly against the revealed rib positions on the cover plate, welding accuracy is significantly improved. The room-temperature pressing step also ensures complete fit between the cover plate and the ribs, eliminating gaps and further improving the quality of electron beam welding.

Description

Technical Field

[0001] This invention belongs to the field of electron beam welding technology, and in particular relates to a manufacturing process for a microchannel structure plate. Background Technology

[0002] Microchannel structured plates are welded together from a cover plate and a channel plate. Larger microchannel structured plates typically exceed 300mm in length and width. The surface of the channel plate is divided into multiple microchannels by ribs, each 2-3mm wide, while the microchannels are 4-5mm wide. The microchannels can be straight or irregularly shaped and are used in heat exchange or cooling devices. Currently, these larger microchannel structured plates are usually manufactured using electron beam welding or diffusion welding, but both methods have their own problems.

[0003] When using electron beam welding, after the cover plate covers the ribs, the ribs are not visible from one side of the cover plate, making it impossible to accurately locate their positions. Furthermore, after the cover plate and channel plate are assembled, they generally do not fit completely together, leaving gaps. After electron beam welding, the shrinkage and deformation of the weld seam will increase these gaps, leading to microchannel cross-cavities and affecting welding accuracy and quality. For microchannel structures with a large number of narrow microchannels, the welding volume is large, and the presence of gaps will further amplify the effects of welding deformation, resulting in distortion even when electron beam welding is performed using the coordinate data of the ribs.

[0004] When using diffusion welding, for microchannel structure plates with narrow ribs, the high temperature and high pressure conditions of diffusion welding can cause rib deformation or collapse, or even damage the microchannel structure, affecting the welding quality. Summary of the Invention

[0005] This invention provides a manufacturing process for microchannel structure flat panels, aiming to solve the above-mentioned technical problems.

[0006] This invention is implemented as follows: a manufacturing process for a microchannel structure flat plate includes the following steps:

[0007] Based on the number and size of the microchannels in the designed microchannel structure plate, channels are machined on the top surface of the raw material plate to obtain a channel plate. Ribs are formed between adjacent channels, and a frame is formed between the channels and the edge of the channel plate.

[0008] A cover plate is fitted onto the top surface of the channel plate to cover the channel plate;

[0009] The cover plate is pressed perpendicular to the channel plate so that the bottom surface of the cover plate is in contact with the top surface of the rib and the position of the rib is displayed on the cover plate;

[0010] The cover plate and the rib are welded together using an electron beam at the location of the exposed rib.

[0011] By removing the frame and the portion of the cover plate corresponding to the frame along the outline of the ribs, a microchannel structure plate is obtained.

[0012] Furthermore, the top surface height of the rib is greater than the top surface height of the frame.

[0013] Furthermore, the height difference between the top surface of the rib and the top surface of the frame is 0.1 mm.

[0014] Furthermore, after mounting a cover plate on the top surface of the channel plate to cover the channel plate, the following steps are also included:

[0015] The edge of the cover plate and the edge of the channel plate are fixed by intermittent spot welding using laser welding.

[0016] Furthermore, the yield strength of the cover plate is less than or equal to the yield strength of the channel plate.

[0017] Furthermore, the thickness of the cover plate is 0.5~1.2mm.

[0018] Furthermore, the pressure applied to the cover plate perpendicular to the channel plate direction is the product of the material yield strength of the cover plate and the sum of the top surface areas of all the ribs.

[0019] Furthermore, after the pressure is achieved to press the cover plate perpendicular to the channel plate, the pressure is maintained for 5 to 10 hours.

[0020] Furthermore, at the location of the exposed rib, the cover plate and the rib are welded together using an electron beam to a depth that is 2 to 4 times the thickness of the cover plate.

[0021] The microchannel structure flat panel manufacturing process provided by this invention utilizes room temperature pressing of a cover plate covering the ribs and channels of a base plate, making the rib positions visible on the surface of the cover plate. The pressed cover plate fits tightly against the ribs at the rib locations, and then electron beam welding is used to weld the cover plate to the ribs according to the visible rib positions on the cover plate. Because the pressing process is carried out at room temperature, the ribs on the base plate will not deform due to high temperature and pressure. Furthermore, since electron beam welding is performed directly according to the visible rib positions on the cover plate, the welding accuracy can be significantly improved. The room temperature pressing step also ensures complete fit between the cover plate and the ribs, eliminating gaps and further improving the quality of electron beam welding. In addition, compared to diffusion welding, this invention has lower equipment and manufacturing costs, and a shorter process time. This invention can avoid deformation of the microchannel structure during manufacturing and improve welding quality. Attached Figure Description

[0022] Figure 1 This is a structural diagram of the raw material plate.

[0023] Figure 2 This is a structural schematic diagram of the channel plate.

[0024] Figure 3 This is a structural diagram of the cover plate and channel plate.

[0025] Figure 4 It is a perspective view of the pressing method of the cover plate and channel plate.

[0026] Figure 5 This is a schematic diagram showing the position of the ribs on the pressed cover plate.

[0027] Figure 6 This is a schematic diagram of a microchannel structure plate.

[0028] Figure 7 yes Figure 6 A magnified view of one end of the microchannel.

[0029] The numbers in the diagram represent: 1-raw material plate, 2-channel plate, 3-channel, 4-rib, 5-frame, 6-cover plate, 7-workbench, 8-pressure head, 9-microchannel structure plate, 10-microchannel. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] See Figures 1-7 This invention provides a manufacturing process for a microchannel structure flat plate, which includes the following steps:

[0032] S1: Based on the number and size of the microchannels in the designed microchannel structure plate, grooves 3 are processed on the top surface of the raw material plate 1 to obtain the groove plate 2. Ribs 4 are formed between adjacent grooves 3, and a frame 5 is formed between the edge of the groove 3 and the edge of the groove plate 2.

[0033] like Figure 2 As shown, before manufacturing the microchannel structure plate, a model of the microchannel structure plate with dimensional parameters is pre-designed. The size of the raw material plate 1 is determined according to the length, width and thickness of the model. The same number of channels 3 as the microchannels are processed on the raw material plate 1.

[0034] In this embodiment of the invention, the channel 3 has a wave-shaped structure, with multiple channels 3 arranged at equal intervals, and adjacent channels 3 are separated by ribs 4. The channel plate 2 has a frame 5, and the channels 3 and ribs 4 are located in the concave area enclosed by the frame 5. The top surface height of the ribs 4 is greater than the top surface height of the frame 5.

[0035] S2: Install a cover plate 6 on the top surface of the channel plate 2 to cover the channel plate 2.

[0036] like Figure 3 As shown, in this embodiment of the invention, the length and width of the cover plate 6 are equal to the length and width of the channel plate 2. To prevent the cover plate 6 from slipping or misaligning on the channel plate 2 during subsequent pressing, the following is included after step S2:

[0037] The edge of the cover plate 6 and the edge of the channel plate 2 are fixed by intermittent spot welding using laser welding.

[0038] S3: Press the cover plate 6 in the direction perpendicular to the channel plate 2 so that the bottom surface of the cover plate 6 is in contact with the top surface of the rib 4 and the position of the rib 4 is displayed on the cover plate 6.

[0039] The yield strength of the material of cover plate 6 is less than or equal to the yield strength of the material of channel plate 2. The materials of cover plate 6 and channel plate 2 can be selected as: copper-304 stainless steel, copper-copper, 304 stainless steel-304 stainless steel, Q235 steel-Q235 steel, etc. In addition, the thickness of cover plate 6 is 0.5~1.2mm.

[0040] like Figure 4 , 5 As shown, after the channel plate 2 and the cover plate 6 are assembled, they are placed on the workbench 7 and fixed. The cover plate 6 is pressed down by the pressure head 8. Due to the difference in yield strength, during the pressing process, the position where the cover plate 6 contacts the rib 4 will be supported by the rib 4 and will fit tightly with the rib 4. The position where the cover plate 6 does not contact the rib 4, that is, the position of the cover plate 6 above the channel 3, will undergo plastic deformation in the direction perpendicular to the surface of the cover plate 6 under the pressure of the pressure head 8 due to the lack of support from the rib 4. This makes the surface of the cover plate 6 show the shape and position of the rib 4 and the channel 3.

[0041] To ensure that the pressure of the pressure head 8 can reveal the position of the ribs 4 on the cover plate 6 without damaging the structure of the channel 3 or microchannel, in this embodiment of the invention, when the top surface height of the ribs 4 is greater than the top surface height of the frame 5, the pressure of pressing the cover plate 6 in the direction perpendicular to the channel plate 2 is the product of the yield strength of the material of the cover plate 6 and the sum of the top surface areas of all the ribs 4. Let the pressure of pressing the cover plate 6 in the direction perpendicular to the channel plate 2 be F, the yield strength of the material of the cover plate 6 be σ, and the sum of the top surface areas of all the ribs 4 be S, then F = σS.

[0042] In addition, after the pressure head 8 is pressed down, the frame 5 can play a role in limiting and protecting the position.

[0043] To ensure that the cover plate 6 and the rib 4 are completely fitted together and that the position of the rib 4 is clearly visible on the surface of the cover plate 6, the present invention maintains pressure for 5 to 10 hours after the pressure of pressing the cover plate in the direction perpendicular to the channel plate is reached.

[0044] S4: Electron beam welding is used to weld the cover plate to the rib at the exposed rib position.

[0045] Using electron beam welding, the cover plate 6 is welded to the rib 4 as shown on the cover plate 6. The electron beam weld is perpendicular to the surface of the cover plate 6 and penetrates through the weld. The depth of the electron beam weld is 2 to 4 times the thickness of the cover plate 6.

[0046] S5: Remove the frame 5 and part of the structure corresponding to the frame 5 of the cover plate 6 along the outline of the rib 4 to obtain the microchannel structure plate 9.

[0047] like Figure 6 , 7 As shown, after electron beam welding is completed, the frame 5 is cut off along the wavy structure of the rib 4 on both sides of the length direction of the microchannel 10, and the frame 5 is cut off at both ends of the microchannel 10 to make the edges flush.

[0048] The microchannel structure plate manufacturing process provided in this invention combines pressing and electron beam welding. Compared to using electron beam welding alone, pressing the cover plate and ribs together reveals the position of the ribs on the cover plate, allowing for accurate positioning of the electron beam welding position and improving welding accuracy. Furthermore, the higher degree of adhesion between the cover plate and ribs after pressing also prevents gaps from affecting welding quality. Compared to using diffusion welding alone, this invention is performed at room temperature, preventing deformation of narrow ribs under high temperature and pressure, thus ensuring the integrity of the microchannel structure. In addition, compared to diffusion welding, this invention has lower equipment and manufacturing costs, shorter process time, effectively shortening the manufacturing cycle and reducing production costs.

[0049] The following detailed description is provided through specific embodiments. Example

[0050] This invention provides a manufacturing process for a microchannel structure flat panel, comprising the following steps:

[0051] Prepare the raw material plate and cover plate. The raw material plate is 304 stainless steel plate with a thickness of 8mm and the cover plate is 304 stainless steel plate with a thickness of 1mm. The length of the raw material plate and the cover plate is 380mm and the width is 316mm.

[0052] Multiple grooves are machined at equal intervals on the raw material plate, and ribs are formed between adjacent grooves. The width of the groove is 6mm, and the width of the rib is 3mm. A frame is formed between the groove and the edge of the groove plate. The width of the frame is 20mm, and the top surface of the rib is 0.1mm higher than the top surface of the frame.

[0053] Remove the oil from the cover plate and channel plate, clean them thoroughly, and blow them dry.

[0054] A cover plate is installed on the surface of the channel plate to cover the channel plate, and the edge of the cover plate is fixed to the edge of the channel plate by laser spot welding.

[0055] The pressure to be applied by the pressure head is calculated by multiplying the yield strength of 304 stainless steel by the sum of the top surface areas of all the reinforcing bars.

[0056] Fix the channel plate on the workbench, and use a pressure head to press the cover plate perpendicular to the channel plate. Hold the pressure for 8 hours to make the bottom surface of the cover plate fit with the top surface of the rib and make the position of the rib visible on the cover plate.

[0057] Raise the pressure head, and use electron beam welding to weld the cover plate and ribs at the exposed rib positions. The electron beam welding depth is 2mm, resulting in a microchannel structure plate.

[0058] Individual pressure tests were conducted on each microchannel in the manufactured microchannel structure plate. The results showed that the weld strength of the electron beam welded using the embodiment of the present invention was close to that of the base material, and the individual microchannels formed between the cover plate and the channel plate did not cross-cavity and were free of defects.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A manufacturing process for a microchannel structure flat plate, characterized in that, Includes the following steps: Based on the number and size of the microchannels in the designed microchannel structure plate, channels are machined on the top surface of the raw material plate to obtain a channel plate. Ribs are formed between adjacent channels, and a frame is formed between the channels and the edge of the channel plate. A cover plate is fitted onto the top surface of the channel plate to cover the channel plate; At room temperature, the cover plate is pressed perpendicular to the channel plate so that the bottom surface of the cover plate is in contact with the top surface of the rib and the position of the rib is displayed on the cover plate. The cover plate and the rib are welded together using an electron beam at the location of the exposed rib. By removing the frame and the portion of the cover plate corresponding to the frame along the outline of the ribs, a microchannel structure plate is obtained; The height of the top surface of the rib is greater than the height of the top surface of the frame; The yield strength of the material of the cover plate is less than or equal to the yield strength of the material of the channel plate.

2. The microchannel structure flat plate manufacturing process according to claim 1, characterized in that, The height difference between the top surface of the rib and the top surface of the frame is 0.1 mm.

3. The microchannel structure flat plate manufacturing process according to claim 1, characterized in that, After mounting a cover plate on the top surface of the channel plate to cover the channel plate, the following steps are also included: The edge of the cover plate and the edge of the channel plate are fixed by intermittent spot welding using laser welding.

4. The microchannel structure flat plate manufacturing process according to claim 1, characterized in that, The thickness of the cover plate is 0.5~1.2mm.

5. The microchannel structure flat plate manufacturing process according to claim 4, characterized in that, The pressure applied to the cover plate perpendicular to the channel plate direction is the product of the yield strength of the cover plate material and the sum of the top surface areas of all the ribs.

6. The microchannel structure flat plate manufacturing process according to claim 1, characterized in that, After the pressure reaches the point where the cover plate is pressed perpendicular to the channel plate, maintain the pressure for 5 to 10 hours.

7. The microchannel structure flat plate manufacturing process according to claim 1, characterized in that, At the location of the exposed rib, the cover plate and the rib are welded together using an electron beam to a depth of 2 to 4 times the thickness of the cover plate.

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