A molybdenum metal fitting processing technology and forming system

Abstract

The application discloses a molybdenum metal accessory processing technology, which comprises a plate with a concave surface and an annular extension edge around the plate; the processing technology comprises the following steps: (1) plate punching positioning, (2) liquid filling forming of the plate, (3) heating, shaping and setting, and obtaining the molybdenum metal accessory. The application adopts the liquid filling forming process to replace the existing stamping forming process, specifically, the concave die plate is filled with high-pressure liquid, and the stamping forming method of establishing reverse hydraulic pressure when the convex die plate drives the plate blank into the concave die plate is used. Meanwhile, according to the high strength and high resilience characteristics of the accessory material, the plate punching positioning process is added in the processing process, and the variation coefficient of the accessory is reduced by further heating, shaping and setting after preforming, so that the product shape and size precision are high, the yield is high, and the production cost is low under the premise of meeting the overall reliability and strength requirements of the accessory structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal pressure processing, in particular to a molybdenum metal accessory processing technology and forming system. BACKGROUND

[0002] Molybdenum metal accessories refer to product accessories with specific shapes formed by stamping and pressing molybdenum plates. Since molybdenum has a high melting point of 2620℃ and can still maintain high strength at high temperatures, it has excellent red hardness (hardness retention ability at high temperatures) and is suitable for making accessories in high-temperature environments, such as aircraft engine components and high-temperature molds, and is widely used in high-tech industries such as aviation, aerospace, automobiles, etc. which have high requirements for accessory performance, integrity and reliability under various high-temperature conditions.

[0003] The existing molybdenum metal accessories are usually processed using stamping processing equipment. For example, patent documents CN118417408A, a tungsten-molybdenum alloy plate processing equipment and its processing method, CN221231380U, a anti-deviation molybdenum plate stamping die, and CN220311484U, a molybdenum plate stamping die, etc. The above-mentioned molybdenum metal accessories are all formed by rigid dies composed of a punch and a die, and the power is applied through a mechanical press or a hydraulic press. The punch moves downward to press the plate into the die cavity, and the shape is obtained through plastic deformation. However, the above stamping process has high local contact stress and significant friction, which can easily cause cracking, wrinkling, and other damage phenomena such as severe deformation or cracking, resulting in a low yield rate of only about 50%.

[0004] In addition, the existing stamping processing technology mainly considers how to correct the position of the stamped plate, but does not consider how to prevent the plate from rebounding after stamping. The high elastic modulus of molybdenum materials results in a large amount of material rebound after unloading, making it extremely difficult to control the material rebound in the industry, especially in complex curved surface forming processes, resulting in large dimensional accuracy errors of the accessories, high scrap rates, and high processing costs. Therefore, improvements are needed for the above technical problems. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, one of the purposes of the present application is to provide a molybdenum metal accessory processing technology and forming system.

[0006] The second purpose of the present application is to provide a molybdenum metal accessory processing forming system.

[0007] One of the purposes of the present application is achieved by the following technical scheme: a molybdenum metal accessory processing technology, characterized in that the molybdenum metal accessory includes a plate with a concave surface, and the plate has an annular extension around the periphery; the molybdenum metal accessory processing technology includes the following steps:

[0008] (1) Punching positioning of plate material: the liquid-filled stretch forming die comprises an upper punch plate and a lower die plate arranged in a stacked manner, a die cavity is formed between the punch plate and the die plate, the plate blank is placed in the die cavity of the liquid-filled stretch forming die, the blank holder is annular and is sleeved outside the punch plate, the blank holder moves downward to press the peripheral edge of the plate blank tightly, thus the annular edge is obtained, then the punch pin built in the blank holder punches downward to form at least one positioning hole to position the plate blank;

[0009] (2) Liquid punching forming of plate material:

[0010] The punch plate is driven to move downward by the driving device, the punch plate and the die plate are closed to each other, the die plate is provided with a liquid injection cavity, high-pressure liquid is injected to apply an upward supporting force to the plate blank, the punch plate and the die plate are stretched and deformed to form a curved surface matching the size and shape of the die plate, thus a plate part with a positioning hole and a curved surface is obtained;

[0011] (3) Heating, shaping and setting: the heating and shaping die is heated, the plate part obtained in step (2) is placed in the die cavity of the heating and shaping die, and the plate part is continuously kept warm under high pressure to be shaped and set, the die is opened, and the plate part is taken out, thus a molybdenum metal part is obtained.

[0012] Further, in the punching positioning of plate material in step (1), the blank holder is applied with a pressure of 20-23 MPa, the punch plate is applied with a pressure of 15-16 MPa, and the blank holder and the punch plate are kept at the same pressure for 3-5 s after the downward forming is completed; when punching, the pressure of the blank holder is 23 MPa, and no pressure keeping is required.

[0013] Further, in the liquid punching forming of plate material in step (2), the output pressure of the driving device is 20-30 MPa, the pressure of the high-pressure liquid is 3-5 MPa, and the keeping time is 3-5 s.

[0014] Further, in the heating, shaping and setting in step (3), the heating and shaping die is heated to 90-110℃, the plate part is preheated in a heating furnace to 280-320℃, and after being taken out from the heating furnace, the plate part is quickly placed in the die cavity of the heated heating and shaping die, the plate part is kept at a pressure of 200-250T and a die temperature of 90-110℃ for 25-30 min, and then the workpiece is taken out.

[0015] Further, in the heating, shaping and setting in step (3), the heating and shaping die is heated to 100℃, the plate part is preheated in a heating furnace to 300℃, and after being taken out from the heating furnace, the plate part is quickly placed in the die cavity of the heated heating and shaping die, the plate part is kept at a pressure of 220T and a die temperature of 100℃ for 30 min, and then the workpiece is taken out.

[0016] The second purpose of the present application is achieved by the following technical scheme: a molybdenum metal accessory processing and forming system, comprising a liquid-filled stretch forming die for pre-limiting the position of a slab blank and then processing the slab blank into a preset shape through the principle of liquid-filled stretch forming, and a heating and shaping die for heating and shaping a pre-formed slab blank.

[0017] Further, the liquid-filled stretch forming die comprises a first female die plate, a first male die plate, a pressure ring, and a punching device.

[0018] The pressure ring is sleeved on the outer periphery of the first male die plate and abuts against the outer periphery of the first female die plate. The first male die plate is movably arranged above the center of the first female die plate. The first female die plate is provided with a liquid injection cavity. The first male die plate, the first female die plate, and the pressure ring are closed to each other to form a cavity for forming the shape of the molybdenum metal accessory, or are moved away from each other for demolding to facilitate the removal of the slab.

[0019] The punching device is arranged in the pressure ring. The punching device comprises a piston rod, a punch pin, and an elastic reset member. The pressure ring is provided with a piston cavity for mounting the piston rod, a punch pin cavity for mounting the punch pin, and an oil inlet channel for delivering high-pressure liquid to the piston cavity. The elastic reset member is sleeved on the punch pin and abuts against the punch pin cavity. The oil inlet channel is connected to the high-pressure liquid, which in turn drives the piston rod and the punch pin to move downward, thereby breaking the slab to achieve positioning.

[0020] The first female die plate is provided with a punch pin avoiding channel and a waste material leading-out channel. The slab debris broken by the punch pin is discharged out of the liquid-filled stretch forming die through the waste material leading-out channel.

[0021] Further, two punching devices are arranged on the two sides of the pressure ring symmetrically about the axis.

[0022] Further, the heating and shaping die comprises an upper die seat, a lower die seat, a second female die plate, a second male die plate, and a heating device. The second female die plate and the second male die plate are provided with a cavity for placing the molybdenum metal accessory. The heating device is used for heating the second female die plate and the second male die plate.

[0023] Further, the heating device comprises a first heating ring and a second heating ring respectively wrapped around the outer periphery of the second female die plate and the second male die plate. The first heating ring and the second heating ring are both composed of detachable semi-annular heating sheets.

[0024] Or / and the heating shaping die further comprises heating wire rods respectively arranged in the upper die seat and the lower die seat, heating wire mounting cavities are arranged in the upper die seat and the lower die seat in a longitudinal and transverse staggered manner, and the heating wires are inserted into the heating wire mounting cavities; the upper die seat and the second male die plate are further provided with an upper heat insulation sheet, and the lower die seat and the second female die plate are further provided with a lower heat insulation sheet.

[0025] Compared with the prior art, the application has the beneficial effects that:

[0026] 1、The application adopts a liquid filling forming process to replace the existing stamping forming process, specifically, a high-pressure liquid is filled in the female die plate, and a reverse hydraulic pressure is established when the male die plate drives the plate blank into the female die plate, meanwhile, in view of the high strength and high resilience characteristics of the accessory material, a plate punching positioning process is added in the machining process, and further heating, shaping and setting are performed after preforming, thereby reducing the variation coefficient of the accessory from 0.5 mm to 0.1 mm, under the premise of meeting the overall reliability and strength requirements of the accessory structure, the product shape and size precision is high, the flatness is less than 10 wires, the variation coefficient is less than 0.5 mm, and the good product rate is as high as 85% or more, thereby reducing the production cost.

[0027] 2、In the plate liquid punching forming process of the application, the curved surface forming structure of the metal accessory utilizes the liquid punching forming principle to make the profile material deform according to the preset shape, specifically, the male die plate and the female die plate are matched to adjust the pressure and other parameter conditions in the up-down direction, so that the plate forms a curved surface with high product shape and size adaptability. Further, the application is provided with an internally arranged hydraulic punching device, the hydraulic punching device is connected with high-pressure liquid, and the piston rod and the punch pin are driven to move and punch the plate blank, in the liquid filling forming process, the influence of the up-down direction hydraulic pressure is reduced, thereby effectively limiting the position deviation of the plate blank, thereby effectively ensuring the shape and size precision of the accessory; in addition, the positioning hole formed in the process becomes a limiting hole in the subsequent heating, shaping and setting process, and the preformed accessory can be well set under the high-temperature pressure holding condition, thereby further ensuring the flatness of the accessory.

[0028] 3、In the heating, shaping and setting process of the application, the plate punched and stretched by the liquid is heated, shaped and set, specifically, the heating and pressure holding conditions of the plate are controlled to reduce the deformation coefficient of the plate and improve the flatness of the plate, so that the plate can be applied to high-precision instruments and equipment such as aerospace. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The figure is a schematic view of a molybdenum metal accessory product structure of a preferred embodiment of the application.

[0030] Figure 2Another angle of product structure of the molybdenum metal fitting of the preferred embodiment of the present application;

[0031] Figure 3 Structure diagram of the liquid-filled stretch forming die of the preferred embodiment of the present application;

[0032] Figure 4 Partial exploded diagram of the liquid-filled stretch forming die of the preferred embodiment of the present application;

[0033] Figure 5 Structure diagram of the punching device of the preferred embodiment of the present application;

[0034] Figure 6 Structure diagram of the longitudinal section of the liquid-filled stretch forming die of the preferred embodiment of the present application;

[0035] Figure 7 Structure diagram of the heating and shaping die of the preferred embodiment of the present application;

[0036] Figure 8 Exploded diagram of the heating and shaping die of the preferred embodiment of the present application;

[0037] Figure 9 Structure diagram of the upper die holder / lower die holder of the preferred embodiment of the present application;

[0038] Figure 10 Structure diagram of the second female die plate / second male die plate of the preferred embodiment of the present application.

[0039] In the figure:

[0040] 100, liquid-filled stretch forming die; 11, first female die plate; 111, punch needle avoiding passage; 112, waste material leading-out passage; 113, liquid injection cavity; 12, first male die plate; 13, pressure pad; 131, piston cavity; 132, punch needle cavity; 133, oil inlet passage; 14, punching device; 141, piston rod; 142, punch needle; 143, elastic reset member;

[0041] 200, heating and shaping die;

[0042] 21, upper die holder; 211, heating wire installation cavity; 22, lower die holder; 221, heating wire installation cavity; 23, second female die plate; 24, second male die plate; 241, limiting cavity; 25, heating device; 251, first heating ring; 252, second heating ring; 26, upper heat insulation sheet; 27, lower heat insulation sheet;

[0043] A, plate blank; B, molybdenum metal fitting; B1, annular edge extension; B2, concave surface; B3, positioning hole; a1, hydraulic input port of the punching device; a2, debris discharge port of the punching device; b, high-pressure liquid input passage of the liquid-filled stretch forming die. DETAILED DESCRIPTION

[0044] Hereinafter, the present application will be further described in conjunction with the drawings and the specific embodiments, it should be noted that the following described embodiments or technical features can be combined to form new embodiments without conflict.

[0045] The molybdenum metal accessory B processed by the present application has a specific shape, specifically including a plate with a concave surface B2, the plate has a ring-shaped extension B1 around the periphery, and a positioning hole B3 is formed on the ring-shaped extension B1, as shown in Figures 1-2 ;

[0046] The molybdenum metal accessory B processing process includes the following steps:

[0047] (1) Plate punching positioning: The liquid-filled stretch forming die 100 includes an upper and lower punch plate and a concave die plate, and the punch plate and the concave die plate form a die cavity, the plate blank A is placed in the die cavity of the liquid-filled stretch forming die 100, the pressure ring is annular, and is sleeved outside the punch plate, the pressure ring moves downward to press the peripheral extension of the plate blank A, that is, the ring-shaped extension B1, and then the punch pin 142 built in the pressure ring is punched downward to form at least one positioning hole B3 to position the plate blank position;

[0048] (2) Plate liquid punching forming:

[0049] The punch plate is driven to move downward by the driving device, and the punch plate and the concave die plate are closed to each other, the concave die plate is provided with a liquid injection cavity 113, high-pressure liquid is injected to apply upward supporting force to the plate blank A, and the punch plate and the concave die plate are stretched and deformed to form a curved surface matched with the size and shape of the concave surface B2, thereby obtaining a plate with a positioning hole B3 and a curved surface; in this process, the driving device can use the existing oil cylinder system.

[0050] (3) Heating, shaping and setting: The heating and shaping die is heated, the plate obtained in step (2) is placed in the die cavity of the heating and shaping die, and the plate is continuously heated and shaped under high pressure. Set, open the mold, take out the plate, and obtain the molybdenum metal accessory B.

[0051] The present application adopts a liquid filling forming process instead of the existing stamping forming process, specifically, a high-pressure liquid is filled in the concave die plate, and a reverse hydraulic pressure is established when the male die plate drives the plate blank A into the concave die plate, meanwhile, in view of the high strength and high resilience characteristics of the accessory material, a plate punching positioning process is added in the machining process, and after preforming, further heating, shaping and setting are performed to reduce the variation coefficient of the accessory from 0.5 mm to 0.1 mm, and under the premise of meeting the overall reliability and strength requirements of the accessory structure, high-precision shape and size are obtained, and the flatness is less than 0.5 wires.

[0052] As a further preferred scheme, in the plate punching positioning of step (1), the pressure of the pressure ring is 20-23 MPa, the pressure of the male die plate is 15-16 MPa, and after the lower forming is in place, the pressure ring and the male die plate jointly maintain pressure for 3-5 s; when punching, the pressure of the pressure ring is 23 MPa, and pressure maintenance is not required.

[0053] As a further preferred scheme, in the plate liquid punching forming of step (2), the output pressure of the driving device is 20-30 MPa, the moving speed of the male die plate is fast first and then slow, specifically, the moving speed of the male die plate is fast when it is idle, and the speed becomes slow when it contacts the accessory, the pressure of the high-pressure liquid is 3-5 MPa, and the holding time is 3-5 s.

[0054] In this process, the plate curved surface forming liquid punching forming principle makes the profile material deform according to the preset shape, specifically by adjusting the pressure and other parameter conditions in the up-down direction, the male die plate and the concave die plate cooperate with each other to make the plate form a curved surface with high shape size adaptability to the product. Further, the present application sets an internal hydraulic punching device 14, the hydraulic punching device 14 is connected with high-pressure liquid, drives the piston rod 141 and the punch pin 142 to move, and breaks the plate blank A. In the liquid filling forming process in this process, the influence of the hydraulic pressure in the up-down direction is reduced, thereby effectively limiting the position deviation of the plate blank A, thereby effectively ensuring the shape and size precision of the accessory; in addition, the positioning hole B3 formed in this process becomes a limiting hole in the subsequent heating, shaping and setting process, and the preformed accessory can be well set under the condition of high-temperature pressure holding, thereby further ensuring the flatness of the accessory.

[0055] As a further preferred scheme, in the heating, shaping and setting of step (3), the heating and shaping die is heated to 280-320℃, after the accessory is placed in the cavity of the heating and shaping die, pressure holding is performed under the conditions of pressure 180-250T and temperature 280-320℃ for 15-25 min, and then the temperature is reduced to 80-120℃, and pressure holding is continued for 20-40 min.

[0056] As a further preferred solution, in the heating, shaping and setting of step (3), the heating and shaping die is heated to 300 DEG C, the plate is placed in the cavity of the heating and shaping die, and then the pressure is maintained at 220T and the temperature is maintained at 300 DEG C for 18 minutes, and then the temperature is lowered to 100 DEG C and the pressure is maintained for another 30 minutes.

[0057] In this process, the plate after the hydrodynamic stretch forming is heated, shaped and set, the heating and pressure maintaining conditions of the plate are controlled, the deformation coefficient of the plate is reduced, the flatness of the plate is improved, and the plate can be applied to high-precision instruments and equipment such as aerospace.

[0058] As shown in Figures 3-10 The application also provides a processing and forming system for a molybdenum metal accessory B, which comprises a hydrodynamic stretch forming die 100 for pre-limiting the position of a plate blank A and then processing the plate blank A into a preset shape through the principle of hydrodynamic stretch forming, and a heating and shaping die 200 for heating, shaping and setting the pre-formed plate blank A.

[0059] As a further preferred solution, the hydrodynamic stretch forming die 100 comprises a first female die plate 11, a first male die plate 12, a pressure ring 13 and a punching device 14.

[0060] The pressure ring 13 is sleeved on the outer periphery of the first male die plate 12 and abuts against the outer periphery of the first female die plate 11, the first male die plate 12 is movably arranged above the center of the first female die plate 11, and the first female die plate 11 is provided with a liquid injection cavity 113, as shown in the figure, the b direction is a high-pressure liquid input channel of the hydrodynamic stretch forming die, the first male die plate 12, the first female die plate 11 and the pressure ring 13 are closed to each other to form a cavity for forming the shape of the molybdenum metal accessory B, or are away from each other for demolding to facilitate taking out the plate;

[0061] The punching device is arranged in the pressure ring 13, the punching device 14 comprises a piston rod 141, a punch pin 142 and an elastic reset member 143, the pressure ring 13 is provided with a piston cavity 131 for mounting the piston rod 141, a punch pin cavity 132 for mounting the punch pin 142 and an oil inlet channel 133 for supplying high-pressure liquid to the piston cavity 131, as shown in the figure, a1 is a hydraulic input port of the punching device; the elastic reset member 143 is sleeved on the punch pin 142 and abuts against the punch pin cavity 132; the oil inlet channel 133 is supplied with high-pressure liquid, which in turn drives the piston rod 141 and the punch pin 142 to move downward, and breaks the plate blank A to realize positioning of the plate blank A;

[0062] The first recess die plate 11 is provided with a punch avoiding channel 111 and a scrap guiding channel 112. The scrap of the plate blank A punched by the punch 142 is discharged out of the liquid-filled stretch forming die 100 through the scrap guiding channel 112. The scrap discharge port of the punching device is in the direction of a2 in the figure.

[0063] As a further preferred solution, the punching device is provided with two, respectively located on the two sides of the axis of the blank holder 13.

[0064] As a further preferred solution, the heating and shaping die 200 comprises an upper die seat 21, a lower die seat 22, a second recess die plate 23, a second convex die plate 24, and a heating device 25. The second recess die plate 23 and the second convex die plate are provided with a cavity for placing the molybdenum metal fitting B. The heating device 25 is used for heating the second recess die plate 23 and the second convex die plate. In the present application, the heating device has multiple embodiments, which can be designed and used in different ways according to the needs of different materials.

[0065] As a further preferred solution, the heating device 25 is a first heating ring 251 and a second heating ring 252 respectively wrapped around the outer periphery of the second recess die plate 23 and the second convex die plate. The first heating ring 251 and the second heating ring 252 are both composed of detachable semi-annular heating sheets.

[0066] Or / and the heating and shaping die further comprises heating wire rods (not shown in the figure) respectively built in the upper die seat 21 and the lower die seat 22. The upper die seat 21 and the lower die seat 22 are both provided with heating wire installation cavities 211 / 221 arranged in a longitudinal and transverse staggered manner. The heating wires are inserted into each heating wire installation cavity 211 / 221. The upper die seat 21 and the second convex die plate are further provided with an upper heat insulation sheet 26, and the lower die seat 22 and the second recess die plate 23 are further provided with a lower heat insulation sheet 27.

[0067] In the first heating mode, the heating sheets are designed as semi-annular heating sheets, and the heat energy is transferred from the outer periphery to the center of the second recess die plate 23 and the second convex die plate. In the second heating mode, multiple detachable heating wires are arranged inside the upper die seat 21 and the lower die seat 22. According to the needs of heat control, the number of heating wires can be increased or reduced, and the heating wires are arranged in a longitudinal and transverse staggered manner, so that the heat is uniformly transferred from the upper and lower directions to the second recess die plate 23 and the second convex die plate. In the third heating mode, the first heating mode and the second heating mode are combined, so that the heat is more uniformly transferred, and the shaping and setting effects are better.

[0068] Example 1

[0069] A molybdenum metal fitting B is processed by a molybdenum metal fitting B processing and forming system, which comprises a liquid-filled stretch forming die 100 for pre-positioning a blank A and then processing the blank A into a preset shape by the principle of liquid-filled stretch forming, and a heating and shaping die for heating, shaping and setting the pre-formed blank A.

[0070] The specific processing process comprises the following steps:

[0071] (1) Punching and positioning of the plate: the liquid-filled stretch forming die 100 comprises an upper punch plate and a lower die plate arranged in a vertical manner, and a die cavity is formed between the punch plate and the die plate. The blank A is placed in the die cavity of the liquid-filled stretch forming die 100, the pressure ring 13 is annular and is sleeved outside the punch plate, the pressure ring 13 moves downward to press the peripheral edge of the blank A, and then the punch pin 142 built in the pressure ring 13 moves downward to punch two positioning holes B3 in the annular peripheral edge B1 to position the blank A. In this process, the driving device of the pressure ring 13 adopts the existing oil cylinder system. In step (1), the pressure applied to the pressure ring is 22 MPa, the pressure applied to the punch plate is 15.5 MPa, and the pressure ring and the punch plate jointly maintain the pressure for 4 seconds after the downward forming is completed. When punching, the pressure of the pressure ring is 23 MPa, and no pressure maintaining is required.

[0072] (2) Liquid forming of the plate:

[0073] The punch plate is driven by the driving device to move downward, the punch plate and the die plate are closed to each other, the die plate is provided with a liquid injection cavity 113, high-pressure liquid is injected to apply an upward supporting force to the blank A, and the punch plate and the die plate are stretched and deformed to form a curved surface matched with the size and shape of the concave surface B2, so as to obtain a plate part with positioning holes B3 and a curved surface. In this process, the driving device adopts the existing oil cylinder system.

[0074] In step (2), the output pressure of the driving device is 25 MPa, the pressure of the high-pressure liquid is 4 MPa, and the holding time is 4 seconds.

[0075] (3) Heating, shaping and setting: the heating and shaping die is heated, the plate part obtained in step (2) is placed in the die cavity of the heating and shaping die, shaping and setting are performed under high pressure, the die is opened, and the plate part is taken out to obtain the molybdenum metal fitting B.

[0076] In step (3), the heating and shaping die is heated to 100℃, the plate part is preheated to 300℃ in a heating furnace, and then is quickly placed in the die cavity of the heated heating and shaping die after being taken out from the heating furnace. The plate part is held under a pressure of 220T and a die temperature of 100℃ for 30 minutes, and then the workpiece is taken out.

[0077] Among them, such as Figures 3-10 As shown, the liquid-filled stretch forming mold 100 of Embodiment 1 includes a first concave template 11, a first convex template 12, a pressure ring 13, and a punching device 14; two punching devices are provided, respectively located on both sides of the pressure ring 13 symmetrically.

[0078] The pressure ring 13 is sleeved on the outer periphery of the first convex template 12 and abuts against the outer periphery of the first concave template 11. The first convex template 12 is movably positioned above the center of the first concave template 11. The first concave template 11 is provided with a liquid injection cavity 113. As shown in the figure, the b direction is the high-pressure liquid input channel of the liquid-filled stretch forming mold. The first convex template 12, the first concave template 11, and the pressure ring 13 are close to each other to form a cavity for forming the shape B of molybdenum metal parts, or they are far apart to demold so as to remove the plate.

[0079] The punching device is disposed inside the pressure ring 13. The punching device 14 includes a piston rod 141, a punch 142, and an elastic reset member 143. The pressure ring 13 is provided with a piston chamber 131 for mounting the piston rod 141, a punch chamber 132 for mounting the punch 142, and an oil inlet channel 133 for supplying high-pressure liquid to the piston chamber 131. As shown in the figure, a1 is the hydraulic input port of the punching device. The elastic reset member 143 is sleeved on the punch 142 and abuts against the punch chamber 132. High-pressure liquid is introduced into the oil inlet channel, which sequentially drives the piston rod 141 and the punch 142 to move downward, penetrating the slab A to achieve the positioning of the slab A.

[0080] The first concave template 11 is provided with a punch avoidance channel 111 and a waste discharge channel 112. The slab A debris pierced by the punch 142 is discharged from the liquid-filled stretch forming mold 100 through the waste discharge channel 112. From the direction a2 in the figure, it is the debris discharge port of the punching device.

[0081] The heating and shaping mold 200 includes an upper mold base 21, a lower mold base 22, a second concave mold plate 23, a second convex mold plate 24, and a heating device 25. A cavity for placing a molybdenum-based metal part B is provided between the second concave mold plate 23 and the second convex mold plate 24. The heating device 25 is used to heat the second concave mold plate 23 and the second convex mold plate 24. In this process, the molybdenum-based metal part B is placed in the cavity between the second concave mold plate 23 and the second convex mold plate 24. When the second concave mold plate 23 and the second convex mold plate 24 are closed, the positioning hole B3 on the molybdenum-based metal part B is extended by the limiting pins built into the second concave mold plate 23 and the second convex mold plate 24, limiting the metal part to a preset position, facilitating subsequent heating and shaping processes.

[0082] The heating device 25 of the embodiment is a first heating ring 251 and a second heating ring 252 respectively wrapped around the outer periphery of the second concave die plate 23 and the second convex die plate 24; the first heating ring 251 and the second heating ring 252 are both composed of a detachable semi-annular heating sheet. The first heating mode is adopted in the embodiment, i.e. the heating sheet is designed as a semi-annular heating sheet, and the heat energy is transferred from the outer periphery to the center position of the second concave die plate 23 and the second convex die plate 24.

[0083] Embodiment 2

[0084] A molybdenum metal fitting B is processed by a molybdenum metal fitting B processing and forming system, which comprises a liquid-filled stretch forming die 100 for pre-limiting the position of a blank A and then processing the blank A into a preset shape by the principle of liquid-filled stretch forming, and a heating and shaping die 200 for heating, shaping and setting the pre-formed blank A.

[0085] The specific processing process comprises the following steps:

[0086] (1) Punching and positioning of the plate: the liquid-filled stretch forming die 100 comprises an upper and lower convex die plate and a concave die plate, a die cavity is formed between the convex die plate and the concave die plate, the blank A is placed in the die cavity of the liquid-filled stretch forming die 100, the pressure ring 13 is annular and is sleeved outside the convex die plate, the pressure ring 13 moves downward to press the peripheral edge of the blank A tightly, i.e. the annular extended edge B1 is obtained, then the punch pin 142 built in the pressure ring 13 punches downward to break the annular extended edge B1 to form at least one positioning hole B3 to position the blank A; in this process, the driving device of the pressure ring adopts the existing oil cylinder system. In the step (1) of punching and positioning of the plate, the pressure of the pressure ring is 20 MPa, the pressure of the convex die plate is 15 MPa, and the pressure ring and the convex die plate jointly maintain pressure for 3 s after being pressed into shape; when punching, the pressure of the pressure ring is 23 MPa and no pressure maintaining is required.

[0087] (2) Liquid punching forming of the plate:

[0088] The convex die plate is driven by the driving device to move downward, the convex die plate and the concave die plate are closed to each other, the concave die plate is provided with a liquid injection cavity 113, high-pressure liquid is injected to apply an upward supporting force to the blank A, and the convex die plate and the concave die plate are stretched and deformed to form a curved surface matched with the size and shape of the concave surface B2, so as to obtain a plate part with the positioning hole B3 and the curved surface; in this process, the driving device adopts the existing oil cylinder system.

[0089] In the step (2) of liquid punching forming of the plate, the output pressure of the driving device is 20 MPa, the moving speed of the convex die plate is fast first and then slow, the pressure of the high-pressure liquid is 3 MPa, and the holding time is 3 s.

[0090] (3) Heating shaping and setting: heating the heating shaping mold 200, placing the plate member obtained in step (2) in the mold cavity of the heating shaping mold 200, continuously keeping warm under high pressure, shaping and setting, opening the mold, taking out the plate member, and obtaining the molybdenum metal part B.

[0091] In step (3) heating shaping and setting, the heating shaping mold is heated to 90°C, the plate member is preheated to 280°C in a heating furnace, and after being taken out from the heating furnace, the plate member is quickly placed in the mold cavity of the heated heating shaping mold, and the plate member is kept under pressure for 25 min under the conditions of a pressure of 200T and a mold temperature of 90°C, and then the workpiece is taken out.

[0092] In the embodiment, the liquid-filled stretch forming mold 100 and the heating shaping mold 200 are consistent with those in embodiment 1.

[0093] Embodiment 3

[0094] A molybdenum metal part B is processed by using a molybdenum metal part B processing and forming system, which comprises a liquid-filled stretch forming mold 100 for pre-limiting the position of the plate blank A and then processing the plate blank A into a predetermined shape by using the principle of liquid-filled stretch forming, and a heating shaping mold 200 for heating shaping and setting the pre-formed plate blank A.

[0095] The specific processing process comprises the following steps:

[0096] (1) Plate punching positioning: the liquid-filled stretch forming mold 100 comprises an upper convex mold plate and a lower concave mold plate, and a mold cavity is formed between the convex mold plate and the concave mold plate. The plate blank A is placed in the mold cavity of the liquid-filled stretch forming mold 100, the pressure ring 13 is annular and is sleeved outside the convex mold plate, the pressure ring 13 moves downward to press the peripheral edge of the plate blank A, and the annular peripheral edge B1 is obtained, and then the punch pin 142 built in the pressure ring 13 moves downward to punch at least one positioning hole B3 to position the plate blank A. In this process, the driving device of the pressure ring 13 can use the existing oil cylinder system. In step (1) plate punching positioning, the pressure of the pressure ring is 23 MPa, the pressure of the convex mold plate is 16 MPa, and the pressure ring and the convex mold plate are kept together for 5 s after being pressed into place. When punching, the pressure of the pressure ring is 23 MPa, and no pressure keeping is required.

[0097] (2) Plate liquid forming:

[0098] The punch plate is driven downward by the driving device, the punch plate and the concave die plate are closed to each other, the concave die plate is provided with a liquid injection cavity 113, high-pressure liquid is injected to apply an upward supporting force to the plate blank A, and the punch plate and the concave die plate are matched to stretch and deform to form a curved surface with the same size and shape as the concave surface B2, so that a plate part with a positioning hole B3 and a curved surface is obtained; in this process, the existing oil cylinder system can be used as the driving device.

[0099] In the liquid punching forming of the plate in step (2), the output pressure of the driving device is 30 MPa, the moving speed of the punch plate is fast first and then slow, the pressure of the high-pressure liquid is 5 MPa, and the holding time is 5 seconds.

[0100] (3) Heating, shaping and setting: the heating and shaping die 200 is heated, the plate part obtained in step (2) is placed in the die cavity of the heating and shaping die 200, and the plate part is shaped and set under high pressure, the die is opened, and the plate part is taken out, so that the molybdenum metal part B is obtained.

[0101] In the heating, shaping and setting of step (3), the heating and shaping die is heated to 110°C, the plate part is preheated to 320°C in a heating furnace, and after being taken out from the heating furnace, the plate part is quickly placed in the die cavity of the heated heating and shaping die, and then the plate part is kept under pressure for 30 min under the conditions of a pressure of 250T and a die temperature of 110°C, and then the workpiece is taken out.

[0102] In this embodiment, the liquid filling and stretching forming die 100 and the heating and shaping die 200 are the same as those in embodiment 1.

[0103] Comparative example 1

[0104] Compared with embodiment 1, the difference between the molybdenum metal part of comparative example 1 and embodiment 1 is that the molybdenum metal part of comparative example 1 is processed by using the existing stamping process. The specific stamping conditions are as follows: under the condition of a pressure of 315 tons, the pressure is kept for 2-3 s.

[0105] Comparative example 2

[0106] Compared with embodiment 1, the difference between the molybdenum metal part of comparative example 2 and embodiment 1 is that in the processing step (1), the punch pin of the punching device is not started, that is, the plate part lacks the positioning process in the liquid punching forming process, and the remaining settings are the same as those of embodiment 1.

[0107] Comparative example 3

[0108] Compared with embodiment 1, the difference between the molybdenum metal part of comparative example 3 and embodiment 1 is that in the processing process, step (3) of heating, shaping and setting is omitted, and the remaining settings are the same as those of embodiment 1.

[0109] Comparative example 4

[0110] Compared with Example 1, the difference of the molybdenum metal part of Comparative Example 4 lies in that, in the processing step (3), the plate preheating step is absent, specifically, the plate is not preheated and is directly placed in the heated cavity of the heated shaping die, and the rest of the settings are the same as those of Example 1.

[0111] Comparative Example 5

[0112] Compared with Example 1, the difference of the molybdenum metal part of Comparative Example 5 lies in that, in the processing step (3), the heating and pressure maintaining conditions are different, specifically, the heated shaping die is heated to 100℃, the plate is preheated to 300℃ in a heating furnace, and after being taken out from the heating furnace, the plate is quickly placed in the heated cavity of the heated shaping die, and then the plate is pressure maintained for 35min under the conditions of a pressure of 180T and a die temperature of 100℃, and the rest of the settings are the same as those of Example 1.

[0113] Comparative Example 6

[0114] Compared with Example 1, the difference of the molybdenum metal part of Comparative Example 6 lies in that, in the processing step (3), the heating and pressure maintaining conditions are different, specifically, the heated shaping die is heated to 100℃, the plate is preheated to 300℃ in a heating furnace, and after being taken out from the heating furnace, the plate is quickly placed in the heated cavity of the heated shaping die, and then the plate is pressure maintained for 20min under the conditions of a pressure of 260T and a die temperature of 100℃, and the rest of the settings are the same as those of Example 1.

[0115] Comparative Example 7

[0116] Compared with Example 1, the difference of the molybdenum metal part of Comparative Example 7 lies in that, in the processing step (3), the heating and pressure maintaining conditions are different, specifically, the heated shaping die is heated to 450℃, and after the plate is placed in the cavity of the heated shaping die, the plate is pressure maintained for 30min under the conditions of a pressure of 220T and a temperature of 450℃, and the rest of the settings are the same as those of Example 1.

[0117] Next, the properties of the molybdenum metal parts processed in each example are measured, and the specific results are shown in Table 1.

[0118] 1. Flatness measurement

[0119] The flatness of the present application, i.e., the flatness, refers to the deformation amount of the product on a reference product surface, which is measured and detected by a three-coordinate dot scanning method.

[0120] 2. Deformation coefficient

[0121] The deformation coefficient of the present application refers to the deformation amount exceeding the stress concentration of the yield strength of the material.

[0122] Table 1: Performance test results of the molybdenum metal parts of each example

[0123] Flatness (unit: filaments) Coefficient of deformation (unit: mm) Example 1 8 0.1 Example 2 12 0.2 Example 3 11 0.25 Comparative Example 1 85 0.8 Comparative Example 2 35 0.65 Comparative Example 3 14 0.95 Comparative Example 4 16 0.6 Comparative Example 5 18 0.7 Comparative Example 6 21 0.8

[0124] The data in the table above shows that the molybdenum metal fittings produced by the process of the present invention have high dimensional accuracy, flatness of less than 10 microns, coefficient of variation of less than 0.5 mm, and a yield rate of over 85%, reducing production costs. In particular, Example 2 is one of the optimal embodiments of the present invention, with high overall dimensional accuracy and a yield rate of over 88%.

[0125] Compared with Example 1, the molybdenum metal parts in Comparative Example 1 are different in that they are processed by existing stamping processes. Cracks appear at the junction of the curved surface and the annular edge of the molybdenum metal parts. The finished product has high resilience, resulting in uneven flatness, especially in the middle of the curved surface. The yield rate is only about 50%.

[0126] Compared with Example 1, the difference of the molybdenum metal parts in Comparative Example 2 is that the punch of the punching device is not activated in the processing step (1). That is, the plate lacks a positioning process during the liquid forming process, which affects the forming in the hydraulic forming process and also affects the forming in the subsequent heating and shaping and setting processes. Ultimately, they jointly affect the flatness and deformation coefficient of the product.

[0127] Compared with Example 1, the difference of the molybdenum metal parts in Comparative Example 3 is that the step (3) heating and shaping is missing in the processing technology, which affects the product variation coefficient and makes the product prone to springback.

[0128] Compared with Example 1, the difference between the molybdenum metal parts in Comparative Examples 4-6 is that the preheating or heating and pressure holding conditions of the product are different in processing step (3), which affects the flatness and coefficient of variation of the product to a certain extent.

[0129] Compared with Example 1, the difference of the molybdenum metal parts in Comparative Example 7 is that the heating method is different in the processing step (3). If the temperature is too high, the product is easily oxidized and the product cannot meet the standards.

[0130] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A processing technology for molybdenum-based metal parts, characterized in that, The molybdenum-based metal fitting includes a plate with a concave surface and an annular rim around its periphery; The processing steps for this molybdenum-based metal fitting include the following: (1) Plate punching and positioning: The liquid-filled stretch forming die includes a first concave plate, a first convex plate, a pressure ring, and a punching device; The first convex template and the first concave template are arranged vertically, forming a mold cavity between them. The pressure ring is annular and is sleeved on the outer periphery of the first convex template and abuts against the outer periphery of the first concave template. The first convex template is movably positioned above the center of the first concave template. The first concave template is provided with a liquid injection cavity. The first convex template, the first concave template, and the pressure ring are close to each other to form a cavity for forming the shape of molybdenum-based metal parts, or they are far apart to demold so as to remove the plate. The punching device is disposed within the pressure ring and includes a piston rod, a punch, and an elastic reset member. The pressure ring is provided with a piston chamber for mounting the piston rod, a punch chamber for mounting the punch, and an oil inlet channel for supplying high-pressure liquid to the piston chamber. The elastic reset member is sleeved on the punch and abuts against the punch chamber. High-pressure liquid is introduced into the oil inlet channel, which sequentially drives the piston rod and punch to move downward, penetrating the slab to achieve slab positioning. The blank is placed in the cavity of the liquid-filled stretch forming mold. The pressure ring moves downward to press the peripheral edge of the blank, thus obtaining the annular edge. Then, the punch inside the pressure ring punches downward to pierce the annular edge and form at least one positioning hole to position the blank. (2) Sheet metal forming: The first convex template is driven to move downward by the driving device. The first convex template and the first concave template close each other. The first concave template is provided with a liquid injection cavity. High-pressure liquid is injected to apply an upward supporting force to the slab. The first convex template and the first concave template cooperate to stretch and deform, forming a curved surface that matches the size and shape of the concave surface, thus obtaining a plate with positioning holes and a curved surface. (3) Heating and shaping: Heating the heating and shaping mold, placing the plate obtained in step (2) in the mold cavity of the heating and shaping mold, and keeping it warm under high pressure to carry out shaping and shaping, opening the mold, taking out the plate, and obtaining molybdenum metal parts.

2. The processing technology for molybdenum-based metal parts as described in claim 1, characterized in that, In step (1) of punching and positioning the sheet metal, a pressure of 20-23 MPa is applied to the pressure ring and a pressure of 15-16 MPa is applied to the first convex template. After the pressing is completed, the pressure ring and the first convex template are held together for 3-5 seconds. When punching, the pressure of the pressure ring is 23 MPa and no pressure holding is required.

3. The processing technology for molybdenum-based metal parts as described in claim 1, characterized in that, In step (2) sheet metal forming, the output pressure of the drive device is 20-30 MPa, the pressure of the high-pressure liquid is 3-5 MPa, and the holding time is 3-5 s.

4. The processing technology for molybdenum-based metal parts as described in claim 1, characterized in that, In step (3) heating and shaping, the heating and shaping mold is heated to 90-110℃. The plate is placed in the heating furnace and heated to 280-320℃. After being taken out of the heating furnace, it is quickly placed into the heated shaping mold cavity. The plate is then held under pressure of 200-250T and mold temperature of 90-110℃ for 25-30 minutes before the workpiece is taken out.

5. The processing technology for molybdenum-based metal parts as described in claim 4, characterized in that, In step (3) heating and shaping, the heating and shaping mold is heated to 100°C. The plate is placed in the heating furnace and heated to 300°C. After being taken out of the heating furnace, it is quickly placed into the heated shaping mold cavity. The plate is then held under pressure of 220T and mold temperature of 100°C for 30 minutes before the workpiece is taken out.

6. A processing and forming system for molybdenum-based metal parts, characterized in that, The system includes a liquid-filled stretch forming mold for pre-defining the position of a slab and then processing the slab into a preset shape using the principle of liquid-filled stretch forming, and a heating forming mold for heating and shaping the pre-formed slab. The molybdenum metal parts processing and forming system processes molybdenum metal parts according to the processing technology described in any one of claims 1-5.

7. The molybdenum-based metal parts processing and forming system as described in claim 6, characterized in that, The first concave template is provided with a punch avoidance channel and a waste discharge channel. The slab fragments pierced by the punch are discharged from the liquid-filled stretching forming mold through the waste discharge channel.

8. The molybdenum-based metal parts processing and forming system as described in claim 6, characterized in that, Two punching devices are provided, located on opposite sides of the pressure ring symmetrically.

9. The molybdenum-based metal parts processing and forming system as described in claim 6, characterized in that, The heating and shaping mold includes an upper mold base, a lower mold base, a second concave mold plate, a second convex mold plate, and a heating device; a cavity for placing molybdenum-based metal parts is provided between the second concave mold plate and the second convex mold plate; the heating device is used to heat the second concave mold plate and the second convex mold plate.

10. The molybdenum-based metal parts processing and forming system as described in claim 9, characterized in that, The heating device consists of a first heating ring and a second heating ring respectively covering the outer periphery of the second concave template and the second convex template; both the first heating ring and the second heating ring are composed of detachable semi-annular heating plates. The heating and shaping mold may also include heating screws respectively built into the upper mold base and the lower mold base. The upper mold base and the lower mold base are provided with heating wire mounting cavities arranged in a crisscross pattern. The heating wires are inserted into each heating wire mounting cavity. An upper heat insulation plate is also provided between the upper mold base and the second convex mold plate, and a lower heat insulation plate is also provided between the lower mold base and the second concave mold plate.

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