A reverse progressive pneumatic expansion forming device and method for difficult-to-deform materials

Abstract

The present invention discloses a reverse progressive pneumatic inflation forming device and method for difficult-to-deform materials. According to the progressive forming processing technology, the present invention discretizes the target profile of the workpiece to be formed into several layers of to-be-formed areas in the vertical direction, and then discretizes each layer of to-be-formed areas into several sub-areas to be formed in the horizontal direction, plans a forming path according to the sub-areas to be formed, and uses a local pneumatic inflation forming process to process the sub-areas to be formed one by one, and then manufactures the target profile that meets the requirements layer by layer in the vertical direction of the workpiece to be formed. The present invention proposes the concept of local pneumatic inflation forming for the first time, thereby organically combining the two modes of pneumatic inflation forming and progressive forming. For difficult-to-deform materials or components with complex cross-sections, it can not only improve the forming limit of the formed parts, but also improve the surface quality of the formed parts, and at the same time has the advantages of low tool cost, short heating time, and no need for specific molds.

Description

Technical Field

[0001] The present invention belongs to the technical field of forming difficult-to-deform metal materials, and specifically relates to combining the characteristics of traditional gas expansion and induction heating progressive forming processes, in particular to a reverse progressive gas pressure expansion forming device and method for difficult-to-deform materials. Background Art

[0002] In the national equipment manufacturing industry, difficult-to-deform materials have a wide range of applications. For example, high-temperature alloys such as titanium alloys are mostly used in the fields of aerospace, automobile manufacturing, etc. With the continuous development of the economy, the country's demand for difficult-to-deform materials is increasing. The main difficult-to-deform materials have good performance, such as high-temperature alloys such as titanium alloys and magnesium alloys. They still have high strength and rigidity in high temperature environments, and have the advantages of low density, high specific strength, and good corrosion resistance. However, difficult-to-deform materials are difficult to deform at room temperature, have poor forming performance, and have serious springback. These shortcomings have hindered the application of difficult-to-deform materials in the past few years. With the research of scholars, the processing methods for difficult-to-deform materials have made considerable progress.

[0003] Incremental forming technology is suitable for processing relatively complex curved surfaces and difficult-to-process materials in the aerospace field. It has the advantages of high forming degree and low cost when manufacturing small batches of parts, but the disadvantage is that the friction generated by the extrusion between the tool head and the plate will reduce the quality of the processed surface, and the single-point extrusion friction will reduce the thinning rate of the formed part. The characteristic of incremental forming is single-point forming, and the advantage is that it can improve the forming limit of the material; the inflation forming method is integral forming, and the advantage is that the surface quality of the formed part is good. In recent years, some scholars have made great progress in the research of incremental forming.

[0004] The single-point incremental forming local heating workbench disclosed in Chinese patent CN 201920027456.5 can form some difficult-to-form metals such as magnesium alloys and titanium alloys. The resistance wire heating coil in the heating assembly heats the blank synchronously, and controls the temperature of the heated area of ​​the blank to be near the target temperature, so that the resistance wire always processes the area to be formed. After the plate is heated, it will be formed into a three-dimensional entity in the horizontal and vertical directions under the continuous extrusion and friction of the tool head. The performance of the formed parts by this method is higher than that of traditional incremental forming. Electric pulse assisted single-point incremental forming technology combines electric pulse assisted forming technology with local loading forming process. The advantage is that the use of electric auxiliary heating can shorten the heating time and significantly improve the forming performance of the plate. It is an advanced plate processing and manufacturing technology, but the disadvantage is that the device is relatively complex and the processing cost is high. In addition, the extrusion of the tool head reduces the surface quality of the plate. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a reverse progressive pneumatic inflation forming device for difficult-to-deform materials, which is used for processing difficult-to-deform materials or components with complex cross-sections. The device organically combines the pneumatic inflation forming process with the induction heating progressive forming process, which not only improves the forming limit and saves heating time, but also improves the surface quality of the processed plate.

[0006] In order to achieve the above technical objectives, the present invention will adopt the following technical solutions:

[0007] A reverse progressive pneumatic bulging forming method for a difficult-to-deform material is characterized in that, according to the progressive forming processing technology, after the target profile of the workpiece to be formed is discretized into a plurality of layers of to-be-formed regions in the vertical direction, each layer of the to-be-formed regions is discretized into a plurality of to-be-formed sub-regions in the horizontal direction, a forming path is planned according to the sub-regions to be formed, the sub-regions to be formed are processed one by one by a local pneumatic bulging forming process, and then a target profile that meets the requirements is manufactured layer by layer in the vertical direction of the workpiece to be formed; the forming characteristics are as follows:

[0008] (1) After the target surface of the workpiece to be formed is discretized into a plurality of layers of to-be-formed regions in the vertical direction, each layer of the to-be-formed regions is discretized into a plurality of to-be-formed sub-regions in the horizontal direction, and a forming path is planned according to the to-be-formed sub-regions;

[0009] (2) The workpiece to be formed is placed at the forming port of the supporting die, and can be sealed with the air chamber through the pressing block, and the sealing performance meets the requirements;

[0010] (3) A pressurized gas P0 (P0 is less than the room temperature plastic deformation yield pressure P of the workpiece to be formed) is introduced between the workpiece to be formed and the gas chamber cavity. S室 , greater than the plastic deformation yield pressure P of the sheet at high temperature T ST ) and maintain it at a constant pressure P0.

[0011] (4) a movable mold heating assembly (consisting of a tool head, an induction coil, and a concave mold) is arranged on one side of the workpiece to be formed;

[0012] (5) Install the tool head and the infrared imager, and connect the induction coil outside the tool head to the low-voltage and high-current pulse power supply through a wire;

[0013] (6) A low-voltage, high-current pulse power supply provides a specific AC power supply to the induction coil, and the movable mold heating assembly heats the material below it to the forming temperature, so that the material there is reversely bulged to fit the die under the action of a constant internal pressure P0;

[0014] (7) Move the tool head according to the forming path planned in step (1) and repeat step (4), and cyclically form the remaining layers of the to-be-formed area until the target profile is reached.

[0015] (8) Turn off the low-voltage, high-current pulse power supply, then stop supplying air to the air chamber, and take out the formed workpiece after it cools down.

[0016] As a further improvement of the above-mentioned reverse progressive pneumatic inflation forming method, the heating component heats each sub-area by induction heating.

[0017] Another technical object of the present invention is to provide a reverse progressive pneumatic expansion forming device for difficult-to-deform materials, comprising a control device, a supporting die, a heating assembly, a driving mechanism and a tool head, wherein:

[0018] The supporting mold is provided with an air chamber, the air chamber is provided with an air inlet channel, an exhaust channel and a forming port matching the forming part of the workpiece to be formed, and a pressing block for clamping the workpiece to be formed is provided outside the forming port; the workpiece to be formed is sealed with the air chamber through the pressing block and the supporting mold; the air chamber is pre-filled with gas that will not cause bulging of the workpiece at room temperature through the air inlet channel, and the gas pressure is constant at P0, and the forming part of the workpiece to be formed is in direct contact with the gas with a pressure of P0 in the air chamber through the forming port;

[0019] The tool head is generally cylindrical and suspended above the workpiece to be formed. The upper end of the tool head is the transmission end, which is connected to the power output end of the milling machine or the manipulator; the lower end of the tool head is the forming end, and the die set in the forming end is a truncated cone. After the heated local area fits the mold, the shape of the die is formed. As the die moves, the area to be formed gradually becomes larger.

[0020] The heating assembly includes an induction coil and a low-voltage, high-current pulse power supply connected to the induction coil; the induction coil is close to the forming end of the tool head and is wound around the outside of the tool head;

[0021] The driving mechanism is connected to the control device and can drive the tool head to move in the vertical and horizontal directions to heat the various layers of the workpiece to be formed according to the forming path planned by the control device;

[0022] The air chamber, under the control of the control device, can always maintain the air pressure at P0 during the forming process;

[0023] The heating assembly, under the control of the control device, can heat the sub-region to be formed to the target temperature T; when the air pressure P0 reaches the target temperature T in each sub-region, the corresponding sub-region can be inflated and deformed to fit with the die of the tool head.

[0024] As a further improvement of the above-mentioned reverse progressive pneumatic expansion forming device, the supporting mold is provided with an air chamber at the middle position, and the upper surface of the air chamber forms a forming opening, and the lower ends of the air inlet channel and the exhaust channel are both arranged through the lower surface of the supporting mold, and at the same time, the upper ends of the air inlet channel and the exhaust channel are respectively connected to the bottom of the air chamber.

[0025] As a further improvement of the above-mentioned reverse progressive pneumatic expansion forming device, the driving mechanism is a milling machine or a manipulator.

[0026] As a further improvement of the above-mentioned reverse progressive pneumatic expansion forming device, the tool head is arranged in a cylindrical shape as a whole and is suspended above the workpiece to be formed. The upper end of the tool head is the transmission end, which is connected to the power output end of the milling machine or the manipulator; the lower end of the tool head is the forming end, and the die arranged in the forming end is a truncated cone shape. After the heated local area is fitted with the mold, a die shape is formed. As the die moves, the area to be formed gradually becomes larger.

[0027] As a further improvement of the above-mentioned reverse progressive gas pressure expansion forming device, the gas filled in the air chamber is argon.

[0028] As a further improvement of the above-mentioned reverse progressive pneumatic expansion forming device, the heating component is also equipped with a temperature detection device for real-time sensing of the temperature of the forming processing part; the temperature detection device is a thermal imager.

[0029] As a further improvement of the above reverse progressive pneumatic expansion forming device, the low voltage and high current pulse power supply can output 5-10A / mm 2 , the duty cycle is 5%.

[0030] According to the above technical solution, compared with the prior art, the present invention has the following advantages:

[0031] The present invention proposes the concept of local inflation forming for the first time, thereby organically combining the inflation forming process and the progressive forming process. This forming process can improve the forming limit and surface quality of the formed parts for difficult-to-deform materials or components with complex cross-sections, and has the advantages of low tool cost, short heating time, and no need for specific molds. Specifically:

[0032] The present invention is based on the principle of progressive forming, and plans the forming process path to perform local inflation forming on each sub-region one by one. During local inflation forming, the present invention pre-fills the air chamber with gas at a pressure of P0. Then, under the induction heating of the induction coil on the periphery of the tool head, the sub-region of the workpiece to be formed can be heated and expanded outward when reaching the preset target temperature T, and the expanded shape can be controlled by the local forming surface set at the forming end of the tool head. It can be known that:

[0033] (1) By forming the to-be-formed processing portion of the workpiece to be formed into a target forming surface by the method described in the present invention, it is only necessary to set a specific surface (local forming surface) at the forming end of the tool head to finally obtain the target forming surface according to the forming processing path, without setting a specific mold cavity to obtain the target forming surface. In other words, the present invention obtains different target forming surfaces by changing the forming processing path;

[0034] (2) Since the heated area of ​​the workpiece to be formed is always the corresponding forming processing part at the current moment, the forming limit of the sheet in the heated area can be maximized;

[0035] (3) Due to the increased plasticity of the heated sheet, it can be reversely convexly formed under the action of gas pressure P0, without the extrusion and friction between the tool head and the sheet, which can greatly improve the surface quality of the formed part;

[0036] (4) The present invention heats the plate through an electromagnetic induction heating coil, and uses a control device to control the driving mechanism to drive the tool head to perform local heating in the area that needs to be heated. Therefore, the heating area can be controlled and kept away from the non-forming area, which can improve the forming limit and precision of the blank.

[0037] (5) The present invention uses induction coil heating to shorten the heating time. The heating method of the forming equipment is simple, the number and cost of equipment are reduced, and energy consumption is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of the reverse progressive pneumatic inflation forming device (local inflation forming of a sub-region of a workpiece to be formed) of the present invention;

[0039] Figure 2 It is a decomposition schematic diagram of the forming process of local inflation forming of a sub-region of a workpiece to be formed;

[0040] Figure 3 is a partial enlarged view of the forming end portion of the middle tool head;

[0041] Figure 4 yes Figure 3 AA section view;

[0042] Figure 5 It is an axonometric view of the tool head;

[0043] Figure 6 It is a bulging temperature distribution diagram of a sub-region of a workpiece to be formed during local bulging forming;

[0044] In the figure: 1. Air inlet channel; 2. Workpiece to be formed; 3. Tool head; 4. Low-voltage large-pulse power supply; 5. Heating component; 6. Induction coil; 7. Infrared thermal imager; 8. Press block; 9. Support mold; 10. Air chamber; 11. Exhaust channel; 12. Control device; 13. Driving mechanism. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise specified, the relative arrangement, expressions and numerical values ​​of the components and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and devices known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and devices should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0046] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations).

[0047] The present invention takes into account that in the prior art, the existing progressive forming method uses a tool to directly mechanically extrude and process the forming surface. Although it can process and form any size, especially large-sized surfaces, at a relatively low cost, this processing method has the disadvantage of low surface quality of the formed surface. The existing inflation forming method generally adopts overall inflation forming, which has a high processing cost and difficulty for the forming processing of large-sized surfaces, and at the same time, the forming limit is also low. Therefore, in view of this technical fact, the present invention provides a reverse progressive pneumatic inflation forming method for difficult-to-deform materials, namely: after the target surface of the workpiece to be formed is discretized into several layers of to-be-formed areas in the vertical direction, each layer of the to-be-formed areas is discretized into several to-be-formed sub-areas in the horizontal direction, a forming path is planned according to the sub-areas to be formed, and the sub-areas to be formed are processed one by one using a local inflation forming process, and then the target surface that meets the requirements is manufactured layer by layer in the vertical direction of the workpiece to be formed.

[0048] According to this technical solution, it can be seen that the present invention combines the incremental forming processing technology with the inflation forming technology to form a local inflation forming processing technology for the workpiece, which makes full use of the advantages of the incremental forming processing technology and the inflation forming technology, so that the formed workpiece has the advantages of good processing accuracy and surface quality, high forming limit, etc., and also has the advantages of low tool cost, short heating time, and no need for specific molds.

[0049] As a further improvement of the above-mentioned reverse progressive pneumatic bulging forming method, the heating component heats each sub-area by induction heating. This heating method heats the induction coil by electromagnetic induction, and then heats the workpiece to be formed. The tool head is controlled by the control device to perform local heating in the area to be heated, and the heating area can be controlled and kept away from the non-forming area, such as Figure 6 As shown in the figure, this can improve the forming limit and precision of the blank. Since the deformation resistance decreases after the sub-region is locally heated, under the same pressure P0, within the set temperature range, the sub-region undergoes local deformation due to its proximity to the tool head.

[0050] In order to realize the above-mentioned reverse progressive pneumatic inflation forming method, the present invention provides a reverse progressive pneumatic inflation forming device for difficult-to-deform materials, including a control device, a supporting mold, a heating component, a driving mechanism and a tool head, wherein:

[0051] The supporting mold is provided with an air chamber, the air chamber is provided with an air inlet channel, an exhaust channel and a forming port matching the forming part of the workpiece to be formed, and a pressing block for clamping the workpiece to be formed is provided outside the forming port; the workpiece to be formed is sealed with the air chamber through the pressing block and the supporting mold; the air chamber is pre-filled with gas that will not bulge at room temperature through the air inlet channel, and the gas pressure is constant at P0, and the forming part of the workpiece to be formed is in direct contact with the gas with a pressure of P0 in the air chamber through the forming port; specifically, the supporting mold is provided with an air chamber at the middle position, the air chamber penetrates the upper surface of the supporting mold to form a forming port, the lower ends of the air inlet channel and the exhaust channel are both provided through the lower surface of the supporting mold, and the upper ends of the air inlet channel and the exhaust channel are respectively connected to the bottom of the air chamber. In other words, the cross-sectional structure of the supporting mold of the present invention is U-shaped as a whole, and the cavity between the two side arms of the U-shaped supporting mold is the above-mentioned air chamber, and the pressing block can dock with the two side arms of the U-shaped supporting mold, so as to seal the workpiece to be formed to the notch of the U-shaped supporting mold. The load applied by the gas pressure P0 is a passive load, which is characterized by increasing the local temperature of the plate and thus changing the effect of the uniformly distributed load generated by the high-pressure gas on the plate, which is determined by the temperature of the induction coil and the distance between the induction coil and the plate.

[0052] The tool head, such as Figure 3-5 As shown, the tool head is set in a cylindrical shape as a whole and is suspended above the workpiece to be formed. The upper end of the tool head is the transmission end, which is connected to the power output end of the milling machine or the manipulator; the lower end of the tool head is the forming end, and the concave die set in the forming end is a truncated cone shape. After the heated local area fits the mold, a concave die shape is formed. As the concave die moves, the area to be formed gradually becomes larger. The position of the tool head from the workpiece to be formed can be adjusted, so that the length of time the tool head heats the sub-area of ​​the workpiece to be formed can be controlled by controlling the distance between the tool head and the workpiece to be formed. The workpiece to be formed expands outward due to heat, which is just restricted by the local forming surface of the tool head, so that the heated area of ​​the workpiece to be formed can be formed according to the preset distance and size. It can be seen from this that in the present invention, the direction of the "reverse progressive air bulging forming" is opposite to the direction of action of the tool head. Under the extrusion force of the gas inside the air chamber, the workpiece to be formed convexly deforms in the opposite direction of the tool head. The shape of the tool head for heating the workpiece to be formed has a concave cavity feature, which has a constraining effect on the bulging distance of the workpiece to be formed (plate) and can control the forming accuracy.

[0053] The heating assembly includes an induction coil and a low-voltage, high-current pulse power supply electrically connected to the induction coil; the induction coil is sleeved on the periphery of the tool head close to the forming end of the tool head, and is arranged close to the upper surface of the workpiece to be formed. The positive and negative electrodes of the low-voltage, high-current pulse power supply are connected through wires to form an electromagnetic induction heating system to achieve local heating of each sub-area of ​​the forming processing part. The low-voltage, high-current pulse power supply can output a current density of 5-10A / mm 2 , with a duty cycle of 5%. The heating assembly is also equipped with a temperature detection device for real-time sensing of the temperature of the forming processing part; the temperature detection device is a thermal imager. The infrared thermal imager is connected to the upper part of the tool head through an insulating bracket, and the two move together to detect in real time the surface temperature of the corresponding position of the sub-area of ​​the workpiece to be formed heated by the induction coil.

[0054] The driving mechanism is connected to the control device and can drive the tool head to move in the vertical and horizontal directions to heat the various layers of the workpiece to be formed according to the forming path planned in the control device, so as to manufacture the target surface that meets the requirements layer by layer at the forming processing part.

[0055] Under the control of the control device, the air chamber can always maintain the air pressure at P0 during the processing process.

[0056] The heating assembly, under the control of the control device, can heat each sub-region of the forming processing part to the target temperature T; when the air pressure P0 in each sub-region reaches the target temperature T, the corresponding sub-region can be inflated and deformed to fit with the die of the tool head. And the pressure P0 is less than the room temperature plastic deformation yield pressure P of the workpiece to be formed. S室 , greater than the plastic deformation yield pressure P of the sheet at high temperature T ST Air pressure.

[0057] Based on the above-mentioned reverse progressive pneumatic inflation forming device, the present invention also provides a reverse progressive pneumatic inflation forming method for difficult-to-deform materials, comprising the following steps:

[0058] (1) After the target surface of the workpiece to be formed is discretized into a plurality of layers of to-be-formed regions in the vertical direction, each layer of the to-be-formed regions is discretized into a plurality of to-be-formed sub-regions in the horizontal direction, and a forming path is planned according to the to-be-formed sub-regions;

[0059] (2) The workpiece to be formed is placed at the forming port of the supporting die, and can be sealed with the air chamber through the pressing block, and the sealing performance meets the requirements;

[0060] (3) A pressurized gas P0 (P0 is less than the room temperature plastic deformation yield pressure P of the workpiece to be formed) is introduced between the workpiece to be formed and the gas chamber cavity. S室 , greater than the plastic deformation yield pressure P of the sheet at high temperature T ST) and maintain it at a constant pressure P0.

[0061] (4) a movable mold heating assembly (consisting of a tool head, an induction coil, and a concave mold) is arranged on one side of the workpiece to be formed;

[0062] (5) Install the tool head and the infrared imager, and connect the induction coil outside the tool head to the low-voltage and high-current pulse power supply through a wire;

[0063] (6) A low-voltage, high-current pulse power supply provides a specific AC power supply to the induction coil, and the movable mold heating assembly heats the material below it to the forming temperature, so that the material there is reversely bulged to fit the die under the action of a constant internal pressure P0;

[0064] (7) Move the tool head according to the forming path planned in step (1) and repeat step (4), and cyclically form the remaining layers of the to-be-formed area until the target profile is reached.

[0065] (8) Turn off the low-voltage, high-current pulse power supply, then stop supplying air to the air chamber, and take out the formed workpiece after it cools down.

Claims

1. A reverse progressive pneumatic expansion forming device for difficult-to-deform materials, characterized in that: It includes a control device, a supporting mold, a heating component, a driving mechanism and a tool head, wherein: The supporting mold is provided with an air chamber, the air chamber is provided with an air inlet channel, an exhaust channel and a forming port matching the forming part of the workpiece to be formed, and a pressing block for clamping the workpiece to be formed is provided outside the forming port; the workpiece to be formed is sealed with the air chamber through the pressing block and the supporting mold; the air chamber is pre-filled with a gas that will not cause bulging of the workpiece at room temperature through the air inlet channel, and the gas pressure is constant at P0, and the forming part of the workpiece to be formed is in direct contact with the gas with a pressure of P0 in the air chamber through the forming port; The tool head is cylindrical in shape and suspended above the workpiece to be formed. The upper end of the tool head is the transmission end, which is connected to the power output end of the milling machine or the manipulator. The lower end of the tool head is the forming end. The concave die set in the forming end is in the shape of a truncated cone. After the heated local area fits the mold, the concave die shape is formed. As the concave die moves, the area to be formed gradually becomes larger. The heating assembly includes an induction coil and a low-voltage, high-current pulse power supply connected to the induction coil; the induction coil is close to the forming end of the tool head and is wound around the outside of the tool head; The driving mechanism is connected to the control device and can drive the tool head to move in the vertical and horizontal directions to heat the various layers of the workpiece to be formed according to the forming path planned by the control device; The air chamber, under the control of the control device, maintains the air pressure at P0 during the forming process; The heating assembly, under the control of the control device, heats the sub-region to be formed to a target temperature T; The gas pressure P0 is less than the room temperature plastic deformation yield pressure P of the workpiece to be formed. S室 , greater than the plastic deformation yield pressure P of the workpiece at high temperature T ST When the air pressure P0 reaches the target temperature T in each sub-area, the corresponding sub-area expands and deforms until it fits with the die of the tool head.

2. The reverse progressive pneumatic bulging forming device for difficult-to-deform materials according to claim 1, characterized in that: The support mold is provided with an air chamber in the middle position, and a forming opening is formed on the upper surface of the air chamber. The lower ends of the air inlet channel and the exhaust channel are both arranged through the lower surface of the support mold, and the upper ends of the air inlet channel and the exhaust channel are respectively connected to the bottom of the air chamber.

3. The reverse progressive pneumatic bulging forming device for difficult-to-deform materials according to claim 1, characterized in that: The gas filled in the gas chamber is an inert gas that needs to maintain stable performance under high temperature and high pressure. The inert gas is argon.

4. The reverse progressive pneumatic bulging forming device for difficult-to-deform materials according to claim 1, characterized in that: The heating component is also equipped with a temperature detection device for real-time monitoring of the temperature of the forming processing part; the temperature detection device is a thermal imager.

5. A method for reverse progressive pneumatic bulging forming of a difficult-to-deform material, using the reverse progressive pneumatic bulging forming device for a difficult-to-deform material according to claim 1, It is characterized by the following steps: (1) After the target surface of the workpiece to be formed is discretized into a plurality of layers of to-be-formed regions in the vertical direction, each layer of the to-be-formed regions is discretized into a plurality of to-be-formed sub-regions in the horizontal direction, and a forming path is planned according to the to-be-formed sub-regions; (2) The workpiece to be formed is placed at the forming port of the supporting die, and can be sealed with the air chamber through the pressing block, and the sealing performance meets the requirements; (3) introducing pressurized gas between the workpiece to be formed and the air chamber cavity and maintaining it at a constant pressure P0; (4) a movable mold heating assembly is arranged on one side of the workpiece to be formed, wherein the movable mold heating assembly includes a tool head and an induction coil; (5) installing the tool head and the infrared imager, and connecting the induction coil outside the tool head to a low-voltage, high-current pulse power supply through a wire; (6) A low-voltage, high-current pulse power supply provides a specific AC power supply to the induction coil, and the movable mold heating assembly heats the material below it to the forming temperature, so that the material there is reversely bulged to fit the die under the action of a constant pressure P0; (7) moving the tool head according to the forming path planned in step (1) and repeating step (4), and cyclically forming the remaining layers of the to-be-formed areas until the target profile is reached; (8) Turn off the low-voltage, high-current pulse power supply, then stop supplying air to the air chamber. Wait for the formed workpiece to cool down before taking it out.

6. A method for reverse progressive pneumatic bulging forming of a difficult-to-deform material according to claim 5, characterized in that: The heating component heats each sub-area to be formed by induction heating.

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