Large-area surface multistage complex microstructure composite forming device and method

Abstract

The invention discloses a large-area surface multistage complex microstructure composite forming device which comprises an electric field auxiliary micro-rolling forming mechanism and an electric field auxiliary micro-die forming mechanism, the electric field auxiliary micro-rolling forming mechanism comprises a pulse power source, a feeding mechanism, a roughing roller, a finishing roller and a discharging mechanism, and the feeding mechanism, the roughing roller, the finishing roller and the discharging mechanism are sequentially arranged in the conveying direction. The electric field assisted micro die forming mechanism comprises a die pressing mechanism and pressure equipment located above the die pressing mechanism, the die pressing mechanism comprises a male die and a blank groove formed below the male die, and a plurality of microstructures are formed in the bottom end of the male die. According to the forming device, the rough roller, the finish roller and the pulse power source are arranged on the electric field auxiliary micro-rolling forming mechanism, the surface of a material is subjected to rolling forming twice under the heating condition, a basic structure is obtained, then the material is subjected to multi-stage complex microstructure forming through the male die, and the material is subjected to multi-stage complex microstructure forming. The method is suitable for the technical field of machining and plastic micro-forming.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing and plastic micro-forming, and in particular relates to a large-area surface multi-level complex micro-structure composite forming device and method. Background Art

[0002] Steam chamber technology is a heat dissipation technology developed based on the heat dissipation technology of the vacuum chamber heat spreader, also known as a flat heat pipe. The overall thickness of the micro steam chamber is generally less than 2 mm, which significantly increases the heat transfer area with the heat-generating components and can better exert the heat transfer capacity of the heat pipe, especially in the field of heat dissipation of high-density electronic devices in space satellites. It has great application potential. Micro steam chambers in space environments are mainly made of materials such as aluminum, nickel, titanium and their alloys, among which the capillary structure wick processing methods are mainly etching, micro-electrical spark, micro-machining, etc. These micro-machining technologies have varying degrees of limitations in terms of processing efficiency, machinable materials and types of parts, and it is difficult to meet the capillary structure manufacturing requirements.

[0003] Plastic micro-forming is a micro-manufacturing technology that uses plastic deformation to form micro-components. It has the characteristics of simple process, high efficiency, good repeatability, high part precision and excellent mechanical properties. Among them, surface microstructure plastic forming technology based on micro-molding technology and micro-rolling technology has become an important processing method for large-area surface microstructures.

[0004] The Chinese invention patent "A device and method for cross-scale compression molding of large-area array microstructures" (Announcement No. CN114260351B) effectively solves the technical problems of difficulty in filling blanks and exhaust during compression molding of large-area multi-scale array microstructures. The Chinese invention patent "A micro-groove plate with dual performance and its composite forming process and equipment" (Announcement No. CN114192797B) uses pulse current to assist in micro-rolling of composite material blanks to obtain micro-groove structures. The Chinese invention patent "A device and method for longitudinal roll forming of fuel cell metal plate flow channels" (Announcement No. CN110125216B) uses pre-formed straight flow channels and secondary formed U-shaped flow channels to increase the flow channel depth to avoid cracking and reduce rebound.

[0005] However, the above-mentioned micro-molding and micro-rolling forming are mainly aimed at some simple and easily deformable materials. With the continuous reduction of the characteristic size of the capillary structure of the steam chamber, the continuous expansion of the scale range, and the increasing number of material types, the micro-rolling and micro-molding technology that simply relies on the mold to apply the force field and the heat source to provide the heat field has become difficult to produce large-area surface microstructures that meet the scale and precision requirements.

[0006] Therefore, there is an urgent need for a device that can efficiently manufacture multi-level complex microstructures on large-area surfaces of difficult-to-deform materials. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a large-area surface multi-level complex microstructure composite forming device. The forming device uses a roughing roller and a finishing roller and a pulse power supply provided in an electric field-assisted micro-rolling forming mechanism to roll-form the material surface twice under heating conditions to obtain a basic structure, and then forms a microstructure of the material with the basic structure through a convex mold combined with a pulse power supply, thereby solving the problem that it is difficult to manufacture a large-area microstructure that meets the scale and accuracy on the surface of a difficult-to-deform material in the prior art.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a large-area surface multi-level complex microstructure composite forming device, characterized in that it includes an electric field-assisted micro-rolling forming mechanism and an electric field-assisted micro-molding forming mechanism, the electric field-assisted micro-rolling forming mechanism includes a pulse power supply and a feeding mechanism, a rough rolling roller, a finishing roller and a unloading mechanism arranged in sequence along the transmission direction, the electric field-assisted micro-molding forming mechanism includes a molding mechanism and a pressure device located above the molding mechanism, the molding mechanism includes a punch and a blank groove arranged below the punch, and a plurality of microstructures are opened at the bottom end of the punch.

[0009] The above-mentioned large-area surface multi-level complex microstructure composite forming device is characterized in that the rough rolling roll is composed of an upper rough rolling roll and a lower rough rolling roll, the finishing rolling roll is composed of an upper finishing roll and a lower finishing roll, the pulse power supply is connected to the upper rough rolling roll and the lower finishing roll through a wire, a plurality of first structures are opened on the rolling surface of the upper rough rolling roll, and a plurality of second structures are opened on the rolling surface of the upper finishing roll.

[0010] The above-mentioned large-area surface multi-level complex microstructure composite forming device is characterized in that the surface roughness of the second structure is higher than that of the first structure.

[0011] The above-mentioned large-area surface multi-level complex microstructure composite forming device is characterized in that the top of the punch is connected to an upper insulating plate, the top of the upper insulating plate is fixedly connected to an upper template, both sides of the upper template are connected to guide pillars through guide sleeves, a punch is provided on the upper template, and a pressure device is provided on the top of the punch; the bottom end of the blank groove is fixedly connected to a pad, the bottom end of the pad is fixedly connected to a lower insulating plate, the bottom end of the lower insulating plate is fixedly connected to a lower template, and the lower template is connected to the lower end of the guide pillar through a guide sleeve; the pad and the punch are both connected to a pulse power supply through wires.

[0012] The above-mentioned large-area surface multi-level complex microstructure composite forming device is characterized in that a limiting column is arranged inside the punch, and the bottom of the limiting column protrudes from the bottom surface of the punch.

[0013] The present invention also discloses a large-area surface multi-level complex microstructure composite forming method, which is characterized in that the large-area surface multi-level complex microstructure composite forming device is used, and the forming method comprises the following steps:

[0014] Step 1: Pre-process the front end of the blank to be formed into a slope and place it on the feeding mechanism, adjust the roller spacing of the roughing roller and the finishing roller, start the feeding mechanism, the roughing roller and the finishing roller, and insert the front end of the blank to be formed into the roughing roller and the finishing roller to ensure that the roughing roller and the finishing roller are in close contact with the blank to be formed at the same time to form an electric circuit;

[0015] Step 2: Use a pulse power supply to heat the blank to be formed in the step 1, and after reaching the roll forming temperature, perform roll forming of the basic structure to obtain a blank, and turn off the pulse power supply;

[0016] Step 3, trimming the blank obtained in step 2 and placing it in the blank groove, controlling the pressure device to move downward to drive the punch downward, so that the punch and the blank groove press the blank tightly;

[0017] Step 4: Use a pulse power supply to heat the blank pressed by the punch in step 3, keep it warm after reaching the molding temperature, and then continue to move the punch downward to apply force to the blank to deform the blank in stages. After the molding is completed, turn off the pulse power supply and obtain the part after cooling.

[0018] The above-mentioned large-area surface multi-level complex microstructure composite forming method is characterized in that the material of the blank to be formed in step one is one of magnesium and magnesium alloys, titanium and titanium alloys, nickel-based high-temperature alloys, refractory alloys, high-entropy alloys and steel, and the finishing roll spacing is 1.01 to 1.15 times the roughing roll spacing.

[0019] The present invention sets the finishing roll pitch to be 1.01 to 1.15 times the roughing roll pitch, thereby eliminating the springback generated after the first structure is rolled during finishing roll rolling, and simultaneously achieving the shaping of the size and surface accuracy of the first structure.

[0020] The above-mentioned large-area surface multi-level complex microstructure composite forming method is characterized in that the pulse parameters of the pulse power supply heating in step 2 are: frequency 100Hz~3000Hz, current density 50A / mm 2 ~300A / mm 2 The roll forming temperature is 50°C to 400°C.

[0021] The present invention sets the pulse parameters of the pulse power supply according to the material and size of the blank to be formed. The higher the material strength, the greater the current density; the smaller the part size, the smaller the current density and the higher the frequency.

[0022] The above-mentioned large-area surface multi-level complex microstructure composite forming method is characterized in that the pulse parameters of the pulse power supply heating in step 4 are: frequency 100Hz~1000Hz, current density 50A / mm 2 ~500A / mm 2 The molding temperature is 100°C to 700°C, and the insulation time is 2min to 10min.

[0023] The present invention sets the pulse parameters of the pulse power supply according to the material and size of the blank to be formed. Compared with the roller forming in step 2, the compression forming in step 4 has a lower frequency, and a higher current density and a forming temperature.

[0024] The above-mentioned large-area surface multi-level complex microstructure composite forming method is characterized in that the graded molding deformation in step four is to divide the multi-level complex microstructure into several microstructures, and multiple molding deformations are performed by replacing the punch with the corresponding microstructure at the bottom to obtain a part with a multi-level complex microstructure.

[0025] The present invention adopts a graded molding deformation process, and can perform re-pressing on the previous microstructure during the next molding, thereby effectively improving the forming degree and precision of the multi-level complex microstructure.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The present invention combines an electric field-assisted micro-rolling forming mechanism with an electric field-assisted micro-molding forming mechanism to achieve large-area multi-level complex microstructure forming on the material surface; by using the roughing roller and the finishing roller and the pulse power supply provided by the electric field-assisted micro-rolling forming mechanism, the material surface is roll-formed twice under heating conditions to obtain a basic structure, so as to reduce the difficulty of subsequent multi-level complex microstructure forming, and then by using a convex mold to perform micro-molding on the basic structure, the precision forming of the multi-level complex microstructure is achieved.

[0028] 2. The present invention provides a pulse power supply and utilizes the energy, time and position adjustability generated by the pulse current to perform fixed-point heating on the material, thereby improving the machinability of the difficult-to-deform material and achieving the regulation of the material's microstructure and mechanical properties.

[0029] 3. The present invention adopts a multi-step graded forming method to distribute the concentrated stress / strain generated in the multi-level complex microstructure forming process to each step, which can improve the uniformity of deformation, inhibit the generation of forming defects and reduce deformation rebound, thereby improving the geometric accuracy and mechanical properties of the material; at the same time, it can improve the dimensional accuracy of the multi-level complex microstructure and realize the processing of multi-level complex microstructures at the micron level on the material surface.

[0030] 4. The forming method of the multi-level complex microstructure of the present invention is low-cost, low-energy-consuming, and can be mass-produced.

[0031] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of the electric field assisted micro-rolling forming mechanism of the present invention.

[0033] Figure 2 It is a structural schematic diagram of the electric field assisted micro-molding forming mechanism of the present invention.

[0034] Figure 3 for Figure 2 Enlarged view of point A.

[0035] Figure 4 This is a schematic diagram of the cross-sectional structure of the first structure in Example 2 of the present invention.

[0036] Figure 5 It is a schematic diagram of the cross-sectional structure of the second structure in Example 2 of the present invention.

[0037] Figure 6 It is a cross-sectional schematic diagram of several levels of the punch microstructure in Example 3 of the present invention.

[0038] Description of reference numerals:

[0039] 1—Pulse power supply; 2—Feeding mechanism; 3—Unloading mechanism;

[0040] 4—convex mold; 4-1—upper insulating plate; 4-2—upper mold plate;

[0041] 4-3—punch; 4-4—limiting column; 5—blank slot;

[0042] 5-1—base plate; 5-2—lower insulation board; 5-3—lower formwork;

[0043] 6—upper roughing roller; 6-1—first structure; 7—lower roughing roller;

[0044] 8—upper finishing roller; 8-1—second structure; 9—lower finishing roller;

[0045] 10—guide pin; 10-1—guide sleeve; 11—blank to be formed;

[0046] 12—blank; 13—conductor. DETAILED DESCRIPTION

[0047] The large-area surface multi-level complex microstructure composite forming device of the present invention is described in detail through Examples 1 to 3.

[0048] Example 1

[0049] like Figure 1 and Figure 2 As shown, the forming device of this embodiment includes an electric field-assisted micro-rolling forming mechanism and an electric field-assisted micro-molding forming mechanism. The electric field-assisted micro-rolling forming mechanism includes a pulse power supply 1 and a feeding mechanism 2, a rough rolling roller, a finishing roller and a unloading mechanism 3 arranged in sequence along the conveying direction. The electric field-assisted micro-molding forming mechanism includes a molding mechanism and a pressure device located above the molding mechanism. The molding mechanism includes a punch 4 and a blank groove 5 arranged below the punch 4, and a plurality of microstructures are opened at the bottom end of the punch 4.

[0050] In actual use, in this embodiment, an electric field-assisted micro-rolling forming mechanism and an electric field-assisted micro-molding forming mechanism are provided to first micro-roll forming the material and then micro-molding the material to obtain a high-precision multi-level complex microstructure; a pulse power supply 1 is provided to heat the material during the micro-rolling forming and micro-molding forming processes to improve the machinability of the material; a feeding mechanism 2 is provided to convey the material into the roughing roller and the finishing roller for two roll forming processes to improve the accuracy of the basic structure of the material surface, and then the roll-formed material is delivered through the unloading mechanism 3; and the molding mechanism is provided as a punch 4 and a blank groove 5, so that micro-molding can be performed on the basic structure of the material surface to form a multi-level complex microstructure.

[0051] like Figure 1 and Figure 2 As shown, further, in this embodiment, the roughing roll is composed of an upper roughing roll 6 and a lower roughing roll 7, the finishing roll is composed of an upper finishing roll 8 and a lower finishing roll 9, the pulse power supply 1 is connected to the upper roughing roll 6 and the lower finishing roll 9 through a wire 13, a plurality of first structures 6-1 are provided on the rolling surface of the upper roughing roll 6, and a plurality of second structures 8-1 are provided on the rolling surface of the upper finishing roll 8.

[0052] In actual use, in this embodiment, by arranging the upper rough roller 6 and the lower rough roller 7 and the upper fine roller 8 and the lower fine roller 9, the material can be placed between the upper rough roller 6 and the lower rough roller 7 for rough rolling forming, and between the upper fine roller 8 and the lower fine roller 9 for fine rolling forming; the pulse power supply 1 is connected to the upper rough roller 6 and the lower fine roller 9 through the wire 13, and when the material penetrates between the roughing roller and the fine roller and is in close contact with the roughing roller and the fine roller at the same time, an energized circuit can be formed to heat the material, which is beneficial for the first structure 6-1 on the rolling surface of the upper rough roller 6 and the second structure 8-1 on the rolling surface of the upper fine roller 8 to successively process several basic structures on the surface of the material; at the same time, the positions of several first structures 6-1, second structures 8-1 and the microstructures at the bottom of the punch 4 in this embodiment are matched.

[0053] It should be noted that, in this embodiment, the upper rough roller 6 and the lower fine roller 9 are insulated from the rest of the electric field assisted micro-rolling forming mechanism, and the surfaces of the feeding mechanism 2 and the unloading mechanism 3 are made of insulating materials; ensuring that the current circuit of the material, the upper rough roller 6, the lower fine roller 9 and the pulse power supply 1 are insulated from the rest of the electric field assisted micro-rolling forming mechanism.

[0054] like Figure 2 As shown, further, in this embodiment, the top of the punch 4 is connected to an upper insulating plate 4-1, the top of the upper insulating plate 4-1 is fixedly connected to an upper template 4-2, both sides of the upper template 4-2 are connected to guide columns 10 through guide sleeves 10-1, a punch 4-3 is provided on the upper template 4-2, and a pressure device is provided on the top of the punch 4-3; the bottom end of the blank groove 5 is fixedly connected to a pad 5-1, the bottom end of the pad 5-1 is fixedly connected to a lower insulating plate 5-2, the bottom end of the lower insulating plate 5-2 is fixedly connected to a lower template 5-3, and the lower template 5-3 is connected to the lower end of the guide column 10 through a guide sleeve 10-1; the pad 5-1 and the punch 4 are connected to the pulse power supply 1 through a wire 13.

[0055] In actual use, in this embodiment, the upper insulating plate 4-1 is connected to the top of the punch 4, the upper template 4-2 is fixedly connected to the top of the upper insulating plate 4-1, and a punch 4-3 is set on the upper template 4-2, so that the punch 4, the upper insulating plate 4-1 and the upper template 4-2 are formed into a whole, and when the pressure equipment moves downward and contacts the punch 4-3, it drives the whole to move downward; the blank groove 5 is fixedly connected to the pad 5-1, the pad 5-1 is fixedly connected to the lower insulating plate 5-2, and the lower insulating plate 5-2 is fixedly connected to the lower template 5-3. The upper mold plate 4-2 and the lower mold plate 5-3 are connected to each other by using a guide column 10 and a guide sleeve 10-1, so that the punch 4 does not deviate in the horizontal direction during the pressing process, and the punch 4 and the blank groove 5 are properly aligned to avoid the occurrence of mispositioning, thereby ensuring the accuracy of the forming of multi-level complex microstructures; the pulse power supply 1 is connected to the pad 5-1 and the punch 4 through a wire 13 to provide a pulse current, so that the material is heated during the micro-molding process to improve the machinability of the material.

[0056] It should be noted that, in this embodiment, the punch 4 and the pad 5-1 are insulated from the rest of the electric field-assisted micro-molding mechanism to ensure that the current loop formed by the punch 4, the pad 5-1, the material and the pulse power supply 1 are insulated from the rest of the electric field-assisted micro-molding mechanism to prevent the current from causing harm to personnel and mechanisms; at the same time, in this embodiment, insulating bolts are used to connect the punch 4 and the upper insulating plate 4-1, and the pad 5-1 and the lower insulating plate 5-2.

[0057] like Figure 2 and Figure 3As shown, further, in this embodiment, a limiting column 4 - 4 is arranged inside the punch 4 , and the bottom of the limiting column 4 - 4 protrudes from the bottom surface of the punch 4 .

[0058] In actual use, in this embodiment, a limiting column 4 - 4 is provided in the punch 4 to prevent the punch 4 from being over-pressed, thereby preventing abnormal deformation of the multi-level complex microstructure on the surface of the material.

[0059] It should be noted that in this embodiment, by changing the access position of the wire 13, such as connecting the pulse power supply 1 to the upper rough roller 6 and the lower rough roller 7 through the wire 13, or connecting the pulse power supply 1 to both ends of the material through the wire 13, local heating of specific areas of the material can be achieved by changing the position of the current heating, thereby achieving shape control.

[0060] Example 2

[0061] The difference between this embodiment and embodiment 1 is that: Figure 4 and Figure 5 As shown, in this embodiment, the first structure 6-1 is in the shape of a quadrangular pyramid, and the second structure 8-1 is in the shape of a quadrangular pyramid.

[0062] In actual use, in this embodiment, the first structure 6-1 is set to a four-sided pyramid shape and the second structure 8-1 is set to a four-sided pyramid shape. The characteristic dimensions (length, width, height and edge length) of the four-sided pyramid and the four-sided pyramid are all 0.01mm~1mm, and the longitudinal cross-sectional area of ​​the four-sided pyramid is 70%~90% of the longitudinal cross-sectional area of ​​the four-sided pyramid. By reducing the volume of the first structure 6-1 to reduce the deformation amount of the first structure 6-1 during roll forming, the deformation difficulty is further reduced, and the concentrated stress / strain of the rolling process is distributed to the two rolling forming processes; at the same time, the bottom surface shapes and sizes of the four-sided pyramid and the four-sided pyramid are the same, which can reduce the forming difficulty of the second structure 8-1.

[0063] Furthermore, in this embodiment, the surface roughness of the second structure 8 - 1 is higher than that of the first structure 6 - 1.

[0064] In actual use, in this embodiment, the surface roughness of the second structure 8-1 is controlled to be higher than that of the first structure 6-1 to improve the accuracy of the basic material structure; preferably, in this embodiment, the surface roughness Ra of the first structure 6-1 is 3.2, and the surface roughness Ra of the second structure 8-1 is 1.6.

[0065] Example 3

[0066] The difference between this embodiment and embodiment 2 is that: Figure 6As shown, in the present embodiment, a plurality of punches 4 are used to form a multi-level complex microstructure, by dividing the multi-level complex microstructure into several levels of regions along the axial direction, and then including the previous level region in the next level region, several levels of punches 4 whose bottom microstructures have the same shape as the above-mentioned several levels of regions are used to perform micro-molding in sequence, so that when the next level punch 4 is performing molding, the previous level region is re-pressed, thereby effectively improving the forming degree of the multi-level complex microstructure.

[0067] Preferably, in this embodiment, the surface roughness Ra of the microstructure of the punch 4 is set to 0.8, combined with the surface roughness Ra of the first structure 6-1 being 3.2 and the surface roughness Ra of the second structure 8-1 being 1.6, the roughness of the microstructure of the material surface can be continuously reduced during the processing, thereby improving the precision of the multi-level complex microstructure; at the same time, Figure 6 As shown, the microstructure at the bottom of the punch 4 in this embodiment is a terraced shape that is symmetrical on both sides, and the height and step length of each layer of the terraced shape are both 5μm to 500μm, which reduces the scale of the multi-level complex microstructure after micro-molding, from the millimeter level to the micron level, thereby improving the capillary force of the multi-level complex microstructure.

[0068] The large-area surface multi-level complex microstructure composite forming method of the present invention is described in detail through Examples 4 to 7.

[0069] Example 4

[0070] In this embodiment, the blank 11 to be formed is a 1 mm thick TA2 pure titanium plate, and the multi-level complex microstructure is divided into three-level regions along the axial direction, and then the shape of the previous level region is included in the next level. A three-level punch 4 with a bottom microstructure shape consistent with the shape of the above-mentioned three-level region is used for multiple micro-molding. The punch 4 includes a first-level punch, a second-level punch and a third-level punch.

[0071] The forming method of this embodiment comprises the following steps:

[0072] Step 1: Pre-process the front end of the TA2 pure titanium plate into a slope and place it on the feeding mechanism 2, adjust the roller pitch of the roughing roller to 0.92mm and the roller pitch of the finishing roller to 0.88mm, start the feeding mechanism 2, the roughing roller and the finishing roller, and insert the front end of the TA2 pure titanium plate into the roughing roller and the finishing roller to ensure that the roughing roller and the finishing roller are in close contact with the TA2 pure titanium plate at the same time to form an electrical circuit;

[0073] Step 2: Start the pulse power supply 1 to heat the TA2 pure titanium plate formed in the power circuit in step 1. After reaching 250°C, perform basic structure roll forming to obtain blank 12, and turn off the pulse power supply 1. The pulse parameters of the pulse power supply 1 for heating are: frequency 600Hz, current density 150A / mm 2 ;

[0074] Step 3, trim the blank 12 obtained in step 2 and put it into the blank groove 5, control the pressure device downward to drive the first-stage punch to move downward, so that the first-stage punch presses the blank 12;

[0075] Step 4: Start the pulse power supply 1 again to heat the blank 12 pressed by the first-stage punch in step 3. Keep it warm for 3 minutes after reaching 500°C. Then, the first-stage punch continues to move downward to apply force to the blank 12, so that the blank 12 undergoes the first compression deformation. Then, the second-stage punch and the third-stage punch are replaced in turn for compression deformation. After completion, turn off the pulse power supply 1, and obtain the part after cooling. The pulse parameters of the pulse power supply 1 for heating are: frequency 300Hz, current density 350A / mm 2 .

[0076] Example 5

[0077] The blank 11 to be formed in this embodiment is a 1.5 mm thick GH4169 nickel-based high-temperature alloy plate, and the multi-level complex microstructure is divided into four regions along the axial direction, and then the shape of the previous level region is included in the next level, and a four-level punch 4 with a bottom microstructure shape consistent with the shape of the above-mentioned four-level region is used for multiple micro-molding. The punch 4 includes a first-level punch, a second-level punch, a third-level punch and a fourth-level punch.

[0078] The forming method of this embodiment comprises the following steps:

[0079] Step 1: Pre-process the front end of the GH4169 nickel-based high-temperature alloy plate into a slope and place it on the feeding mechanism 2, adjust the roller pitch of the roughing roller to 1.2 mm and the roller pitch of the finishing roller to 1.1 mm, start the feeding mechanism 2, the roughing roller and the finishing roller, and insert the front end of the GH4169 nickel-based high-temperature alloy plate into the roughing roller and the finishing roller to ensure that the roughing roller and the finishing roller are in close contact with the GH4169 nickel-based high-temperature alloy plate at the same time to form an electrical circuit;

[0080] Step 2: Start the pulse power supply 1 to heat the GH4169 nickel-based high-temperature alloy plate that forms the power circuit in step 1. After reaching 230°C, perform basic structure roll forming to obtain a blank 12, and turn off the pulse power supply 1; the pulse parameters of the pulse power supply 1 for heating are: frequency 500Hz, current density 120A / mm 2 ;

[0081] Step 3, trim the blank 12 obtained in step 2 and put it into the blank groove 5, control the pressure device downward to drive the first-stage punch to move downward, so that the first-stage punch presses the blank 12;

[0082] Step 4: Start the pulse power supply 1 again to heat the blank 12 pressed by the first-level punch in step 3. After reaching 450°C, keep it warm for 5 minutes. Then the first-level punch continues to move downward to apply force to the blank 12, so that the blank 12 undergoes the first compression deformation. Then, the second-level punch, the third-level punch and the fourth-level punch are replaced in turn for compression deformation. After completion, turn off the pulse power supply 1 and obtain the part after cooling. The pulse parameters of the pulse power supply 1 for heating are: frequency 220Hz, current density 290A / mm 2 .

[0083] Example 6

[0084] The difference between this embodiment and embodiment 4 is that the blank 11 to be formed is a 3 mm thick TA2 pure titanium plate, the roller pitch of the roughing roll in step 1 is 2.76 mm, and the roller pitch of the finishing roll is 2.42 mm; in step 2, the blank 11 to be formed is heated to 50°C, and the pulse parameters of the pulse power supply 1 are: frequency 2800 Hz, current density 50 A / mm 2 In step 4, the blank 12 is heated to 700°C and then kept warm for 2 minutes. The pulse parameters of the pulse power supply 1 are: frequency 100 Hz, current density 480 A / mm 2 .

[0085] Example 7

[0086] The difference between this embodiment and embodiment 5 is that the blank 11 to be formed is a GH4169 nickel-based high-temperature alloy plate with a thickness of 0.8 mm, the roller pitch of the roughing roll in step 1 is 0.64 mm, and the roller pitch of the finishing roll is 0.63 mm; in step 2, the blank 11 to be formed is heated to 400°C, and the pulse parameters of the pulse power supply 1 are: frequency 100 Hz, current density 300 A / mm 2 In step 4, the blank 12 is heated to 100°C and kept warm for 10 minutes. The pulse parameters of the pulse power supply 1 are: frequency 1000Hz, current density 60A / mm 2 .

[0087] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A large-area surface multi-level complex microstructure composite forming device, characterized in that: The invention comprises an electric field assisted micro-roll forming mechanism and an electric field assisted micro-mold forming mechanism, wherein the electric field assisted micro-roll forming mechanism comprises a pulse power supply (1) and a feeding mechanism (2), a rough rolling roller, a finishing rolling roller and a feeding mechanism (3) arranged in sequence along a conveying direction, and the electric field assisted micro-mold forming mechanism comprises a mold forming mechanism and a pressure device located above the mold forming mechanism, wherein the mold forming mechanism comprises a punch (4) and a blank groove (5) arranged below the punch (4), and a plurality of micro structures are provided at the bottom end of the punch (4).

2. A large-area surface multi-level complex microstructure composite forming device according to claim 1, characterized in that: The roughing rollers are composed of an upper roughing roller (6) and a lower roughing roller (7), and the finishing rollers are composed of an upper finishing roller (8) and a lower finishing roller (9). The pulse power supply (1) is connected to the upper roughing roller (6) and the lower finishing roller (9) via a conductor (13). A plurality of first structures (6-1) are provided on the rolling surface of the upper roughing roller (6), and a plurality of second structures (8-1) are provided on the rolling surface of the upper finishing roller (8).

3. The large-area surface multi-level complex microstructure composite forming device according to claim 2 is characterized in that: The surface roughness of the second structure (8-1) is higher than that of the first structure (6-1).

4. The large-area surface multi-level complex microstructure composite forming device according to claim 1 is characterized in that: The top of the punch (4) is connected to an upper insulating plate (4-1), the top of the upper insulating plate (4-1) is fixedly connected to an upper mold plate (4-2), both sides of the upper mold plate (4-2) are connected to guide pillars (10) through guide sleeves (10-1), a punch (4-3) is provided on the upper mold plate (4-2), and a pressure device is provided at the top of the punch (4-3); the bottom of the blank groove (5) is fixedly connected to a pad (5-1), the bottom of the pad (5-1) is fixedly connected to a lower insulating plate (5-2), the bottom of the lower insulating plate (5-2) is fixedly connected to a lower mold plate (5-3), and the lower mold plate (5-3) is connected to the lower end of the guide pillar (10) through a guide sleeve (10-1); the pad (5-1) and the punch (4) are both connected to a pulse power supply (1) through a wire (13).

5. The large-area surface multi-level complex microstructure composite forming device according to claim 1 is characterized in that: A limiting column (4-4) is arranged inside the punch (4), and the bottom of the limiting column (4-4) protrudes from the bottom surface of the punch (4).

6. A method for composite forming of large-area surface multi-level complex microstructures, characterized in that: Using the large-area surface multi-level complex microstructure composite forming device as claimed in any one of claims 1 to 5, the forming method comprises the following steps: Step 1: After the front end of the blank to be formed (11) is pre-processed into a slope, it is placed on the feeding mechanism (2), the roller spacing between the roughing roller and the finishing roller is adjusted, the feeding mechanism (2), the roughing roller and the finishing roller are started, and the front end of the blank to be formed (11) is inserted into the roughing roller and the finishing roller, ensuring that the roughing roller and the finishing roller are in close contact with the blank to be formed (11) at the same time, so as to form an electric circuit; Step 2: using a pulse power supply (1) to heat the blank (11) to be formed in the power circuit formed in step 1, and after reaching the roll forming temperature, performing roll forming of the basic structure to obtain a blank (12), and then turning off the pulse power supply (1); Step 3, trimming the blank (12) obtained in step 2 and placing it in the blank groove (5), controlling the pressure device to move downward to drive the punch (4) to move downward, so that the punch (4) and the blank groove (5) press the blank (12); Step 4: Use a pulse power supply (1) to heat the blank (12) pressed by the punch (4) in step 3, keep it warm after reaching the molding temperature, then continue to move the punch (4) downward to apply force to the blank (12), so that the blank (12) is deformed by graded molding. After the molding is completed, turn off the pulse power supply (1) and obtain the part after cooling.

7. A large-area surface multi-level complex microstructure composite forming method according to claim 6, characterized in that: The material of the blank (11) to be formed in step 1 is one of magnesium and magnesium alloys, titanium and titanium alloys, nickel-based high-temperature alloys, refractory alloys, high-entropy alloys and steel, and the roller pitch of the finishing roll is 1.01 to 1.15 times the roller pitch of the roughing roll.

8. The method for composite forming of a large-area surface multi-level complex microstructure according to claim 6, characterized in that: The pulse parameters of the pulse power supply (1) in step 2 are: frequency 100Hz-3000Hz, current density 50A / mm 2 ~300A / mm 2 The roll forming temperature is 50°C to 400°C.

9. A large-area surface multi-level complex microstructure composite forming method according to claim 6, characterized in that: The pulse parameters of the pulse power supply (1) in step 4 are: frequency 100Hz~1000Hz, current density 50A / mm 2 ~500A / mm 2 The molding temperature is 100°C to 700°C, and the insulation time is 2min to 10min.

10. A large-area surface multi-level complex microstructure composite forming method according to claim 6, characterized in that: The graded compression molding described in step 4 is to divide the multi-level complex microstructure into several microstructures, and to obtain a part with a multi-level complex microstructure by performing compression molding multiple times by replacing the convex mold (4) with a corresponding microstructure at the bottom.

Images