Superplastic forming diffusion bonding product quality visualization system and visualization method thereof

Abstract

The invention aims to solve the problem that the product quality cannot be known in the existing superplastic forming diffusion bonding process. The invention provides a superplastic forming diffusion bonding product quality visualization system and a superplastic forming diffusion bonding product quality visualization method, and belongs to the field of superplastic forming. According to the invention, the visual device is connected to monitor the stability conditions of the air inlet pressure and the air outlet flow rate in real time, the lower computer and the industrial personal computer are used for data conversion, the computer is used for data management and complex calculation, the terminal display is used for displaying air pressure and flow rate curves, and the product quality problem in the technological process is judged according to the monitored real-time data. The experiment can be terminated in time through air pressure monitoring abnormity when the plate is broken in the superplastic forming process, so that the time period is shortened; and a basis can be provided for process improvement according to the recorded air pressure data, so that the process cycle of good products is greatly shortened. The method is suitable for quality visualization in superplastic forming / diffusion bonding.

Description

Technical Field

[0001] The present invention belongs to the field of superplastic forming, and particularly relates to a superplastic forming diffusion bonding product quality visualization system and method thereof. Background Art

[0002] Superplastic Forming / Diffusion Bonding (SPF / DB) technology is a high-end manufacturing process that combines the high strain rate deformation ability of superplastic materials with the solid-state diffusion metallurgy combination characteristics. Through the controllable deformation and atomic diffusion bonding mechanism in the superplastic state of the material, it can achieve the integral forming of complex hollow components, significantly improving the structural lightweight level and service performance. The SPF / DB process involves complex processes such as high temperature, multi-field coupling, and microstructural evolution, and its quality influencing factors include superplastic behavior of materials, cleanliness of diffusion interfaces, temperature / pressure co-control, etc.

[0003] With the increasing demand for structural weight reduction and function integration in fields such as aerospace and new energy vehicles, traditional mechanical connections (such as riveting and bolt connection) are difficult to meet the requirements due to weight increase and stress concentration problems. The SPF / DB technology realizes the integral forming of multi-layer hollow structures through a single process, which can reduce the number of parts by more than 70%, and at the same time significantly improve the structural stiffness and fatigue life. Compared with traditional forging or machining, the material utilization rate of SPF / DB can reach more than 90%, greatly reducing processing costs and material waste, which conforms to the concept of green manufacturing. SPF / DB is especially suitable for lightweight and high-strength materials such as titanium alloys and aluminum alloys, and its forming temperature and diffusion bonding temperature window highly coincide, providing an ideal solution for the manufacturing of complex components (such as wing ribs and engine blades). Since this technology was first applied in the aerospace field in the 1970s, due to its unique advantages in manufacturing complex lightweight structures, it has gradually become the core process for aeroengine, spacecraft load-bearing components and high-end equipment manufacturing.

[0004] In the SPF / DB process, the control of air pressure is a crucial part of the process flow. By replacing traditional mechanical stamping with inert gas pressure, non-contact loading is the core driving force for material plastic flow in superplastic forming. The gas pressure acts on the surface of the sheet, generating uniform normal stress and driving the material to flow into the die cavity. As time increases, the air intake process will change according to the material forming conditions. Generally, in order to establish a stable strain field and suppress necking in the initial stage, the air intake volume is relatively slow, which can make the material uniformly extend and avoid local thinning; in the middle stage of forming, the air intake volume will be increased to accelerate the material's conforming to the die; in the final stage of forming, in order to fully fill the detailed parts of the die and compensate for the increase in rheological stress caused by thickness reduction, the air intake volume is finely adjusted. The distribution of air pressure during the entire forming process directly affects the thickness uniformity of the product parts. If the local air pressure is too high and the strain rate exceeds the superplastic window, local thinning or even cracking will occur; if the control is improper during the conversion of the air intake volume, resulting in a sudden change in the air pressure gradient and causing instability in material flow, wrinkle defects will be caused. The above situations often occur during the process. The SPF / DB process from material pretreatment to heating, pressurization, cooling, and demolding takes a long time. With the current process means, we can only know whether the formed parts are qualified after the entire process is completed, which greatly increases the process cost. Therefore, solving the visualization of product quality in the superplastic forming / diffusion bonding process is the key to the superplastic forming / diffusion bonding technology. Summary of the Invention

[0005] The object of the present invention is to provide a superplastic forming diffusion bonding product quality visualization system and a visualization method. Through this system and method, the real-time monitoring of air pressure and air flow can be carried out, so that the abnormal situations of air intake and air outlet during superplastic forming can be detected in time, and the forming process can be optimized by regulation to prevent the sheet from cracking or not being formed in place and unable to be laminated, and the forming rate can be improved.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention proposes a superplastic forming diffusion bonding product quality visualization system, which includes a pressure gauge, a flow meter, a lower computer controller, an industrial computer, and a computer;

[0008] The pressure gauge is used to detect the air pressure data at the upper die air inlet and send it to the lower computer controller;

[0009] The flow meter is used to detect the flow rate at the lower die air outlet and send the flow rate to the lower computer controller;

[0010] The lower computer controller is used to send the received air pressure and flow rate data to the industrial computer, and is also used to receive the control instructions sent by the industrial computer and adjust the air pressure at the upper die air inlet;

[0011] The industrial control computer is used to convert the data information received by the lower computer controller into a communication protocol and then transmit it to the computer;

[0012] The computer is used to continuously monitor the air pressure and air flow stability during the intake and exhaust processes through a loop program. When abnormal air pressure is detected, the air pressure valve is adjusted in a timely manner to accurately control the intake air pressure. When the air pressure disappears and the air flow suddenly changes, the process is terminated; if there is no special situation, the monitoring continues and enters the next cycle until the process ends.

[0013] Furthermore, the above computer can display the real-time data of air pressure and flow rate, and display the data curve graphs of air pressure and flow rate.

[0014] The present invention also proposes a method for visualizing the product quality of superplastic forming and diffusion bonding. The visualization method is implemented based on the above-mentioned product quality visualization system, and the visualization method includes the following steps:

[0015] Step S1: Process the sheet to be formed;

[0016] Step S2: Assemble the visualization system and heat up the superplastic forming equipment.

[0017] Step S3: Place the processed sheet into the hot forming equipment, keep it warm for ten minutes after reaching the set temperature, control the upper slider to press down, and keep the pressure after reaching the set pressure;

[0018] Step S4: Apply pressure according to the air pressure loading curve obtained by finite element simulation, keep the pressure for 30 minutes after reaching the maximum pressure, and the visualization system continuously monitors the intake air pressure and exhaust air flow rate during the forming process to judge the internal forming situation;

[0019] Step S5: If there is no abnormal situation, after the forming is completed, cool down to room temperature and then take out the sheet, and remove the sandblasting in the process section;

[0020] Step S6: If there is an abnormal situation, it will automatically start and stop, release the pressure, the slider will move up, directly take out the failed sheet, and repeat the above steps to continue forming.

[0021] Furthermore, the above step S1 is specifically:

[0022] Step S11: Grind the sheet to be formed smoothly, remove the surface oil stain, remove impurities by pickling, and clean and dry it with ethanol;

[0023] Step S12: Spray the release agent on both sides of the dried sheet and dry it with hot air.

[0024] Furthermore, the volume percentage of the pickling liquid is hydrofluoric acid: nitric acid: water = 1:3:6.

[0025] Furthermore, the pickling time is 1 - 5 minutes.

[0026] Further, the above-mentioned step S2 is specifically as follows:

[0027] Step S21: Spray a release agent into the cavity of the hot forming equipment, weld the inlet pipe to the inlet of the upper mold, and weld the outlet pipe to the outlet of the lower mold;

[0028] Step S22: After connecting the inlet pipe to the pressure gauge, connect it to the argon gas cylinder pressure reducer, and connect the outlet to the flow meter.

[0029] Further, the above-mentioned release agent is boron nitride.

[0030] Further, heat the above-mentioned superplastic forming equipment to 850 - 950 °C.

[0031] Further, in the above-mentioned step S4, the superplastic forming pressure is set to 2 MPa, gradually increased at a speed of 0.1 MPa / min, and the pressure is maintained for 30 min after reaching 2 MPa.

[0032] The beneficial effects of the present invention are as follows:

[0033] 1. A method for visualizing the quality of a superplastic forming and diffusion bonding product proposed by the present invention can timely detect abnormal situations of air inlet and outlet during superplastic forming through real-time monitoring of air pressure and air flow, and perform regulation to optimize the forming process, prevent the sheet from cracking or being unable to be formed in place for film pasting, thereby improving the forming rate of the sheet.

[0034] Further, when the sheet has cracked during the superplastic forming process of the present invention, the experiment can be terminated in time through abnormal air pressure monitoring to reduce the time cycle; also, based on the recorded air pressure data, it can provide a basis for process improvement, thereby significantly shortening the good product process cycle.

[0035] Further, the present invention is convenient for product quality analysis and timely decision-making adjustment through intuitive data display; and by recording quality data, it can be used to improve product consistency, ensure that each product meets high-standard requirements; it also provides data support for product quality, facilitating subsequent traceability and analysis, and at the same time reducing the data interpretation threshold for technicians.

[0036] 2. A system for visualizing the quality of a superplastic forming and diffusion bonding product proposed by the present invention has extremely high compatibility, can be applied to common materials of different superplastic forming, adapt to complex geometric shapes such as multi-layer sandwich structures, and break through the space limitations of traditional detection means.

[0037] 3. For the visual quality inspection method of superplastic forming and diffusion bonding products proposed by the present invention, the key difficulty lies in how to determine the forming state based on the data content real-time monitored by the combined visual device. The present invention provides data support for the real-time monitoring of loop instructions through a database formed by verifying a large amount of air pressure and air flow data, and can accurately judge the forming state of the sheet in the process.

[0038] The present invention is applicable to the quality visualization in superplastic forming / diffusion bonding. Brief Description of the Drawings

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 It is a schematic diagram of the principle of the visual quality inspection method of superplastic forming and diffusion bonding products proposed by the present invention;

[0041] Figure 2 is Figure 1 the curve legend mentioned in

[0042] Figure 3 It is the air pressure curve graph described in Embodiment 3;

[0043] Figure 4 It is the air flow curve graph described in Embodiment 3;

[0044] Figure 5 It is the air pressure curve graph described in Embodiment 4;

[0045] Figure 6 It is the air flow curve graph described in Embodiment 4;

[0046] Figure 7 It is the air pressure curve graph described in Embodiment 5;

[0047] Figure 8 It is the air flow curve graph described in Embodiment 5.

[0048] Among them, 1 - upper die, 2 - sheet, 3 - lower die, 4 - hot forming equipment, 5 - intake pipe, 6 - pressure gauge, 7 - gas cylinder, 8 - outlet pipe, 9 - flow rate meter, 10 - lower computer controller, 11 - industrial control computer, 12 - loop instruction, 13 - computer, 14 - curve legend. Detailed Embodiments

[0049] In the following description, specific details such as specific system architectures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0050] The following further details the specific embodiments of the present invention in conjunction with the accompanying drawings. The following embodiments will help those skilled in the art further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made, and these all fall within the protection scope of the present invention.

[0051] Embodiment 1. Refer to Figure 1 and Figure 2 This embodiment describes a system for visualizing the quality of superplastic forming and diffusion bonding products. Through this system, real-time monitoring of air pressure and air flow can be carried out, so as to timely detect abnormal situations of air intake and air outlet during superplastic forming, and adjust and control to optimize the forming process, prevent the sheet from cracking or the forming not being in place and unable to be laminated, and improve the forming rate.

[0052] The product quality visualization system includes a pressure gauge, a flow rate gauge, a lower computer controller, an industrial control computer, and a computer;

[0053] The pressure gauge is used to detect the air pressure data at the air inlet of the upper die and send it to the lower computer controller;

[0054] The flow rate gauge is used to detect the flow rate at the air outlet of the lower die and send the flow rate to the lower computer controller;

[0055] The lower computer controller is used to send the received air pressure and flow rate data to the industrial control computer, and is also used to receive the control instructions sent by the industrial control computer and adjust the air pressure at the air inlet of the upper die;

[0056] The industrial control computer is used to convert the data information received by the lower computer controller into a communication protocol and then transmit it to the computer;

[0057] The computer is used to continuously monitor the stability of air pressure and air flow during the air intake and air outlet processes through a loop program. When abnormal air pressure conditions are detected, the air pressure valve is timely adjusted to accurately control the intake air pressure. When the air pressure disappears and the air flow suddenly changes, the process is terminated; if there is no special situation, the monitoring continues and enters the next loop until the process ends.

[0058] The product quality visualization system proposed in this embodiment, such as Figure 1As shown in the figure, first, the upper die 1 and the lower die 3 are placed in the hot forming equipment 4, then the sheet to be formed is placed in the die, and then the slider is controlled to press down to press the die to prevent air leakage. Finally, the gas cylinder 7 is used to provide air pressure for the air inlet of the upper die 1. Among them, the inlet pipe 5 is connected to the air inlet of the upper die, and at the same time, the pressure gauge 6 is connected to the inlet pipe 5; the outlet pipe 8 is connected to the air outlet of the lower die 3, and the outlet pipe 8 is connected to the flow meter 9, so as to collect the intake air pressure and the outlet air flow rate in real time, which serves as the information source of the data and lays the foundation for subsequent data processing and monitoring. That is, a database formed by verifying a large amount of air pressure and air flow data provides data support for real-time monitoring of the loop instruction, and can accurately judge the forming state of the sheet during the process.

[0059] The pressure gauge 6 and the flow meter 9 are connected to the lower computer controller 10, and the lower computer controller 10 is responsible for receiving the real-time data of air pressure and air flow and executing control instructions to ensure quick response. The industrial control computer 11 converts the data information received by the lower computer controller 10 into a communication protocol and then transmits it to the computer 13, and the computer 13 performs data management and complex calculations. The computer 13 uses a loop program to monitor the stability of air pressure and air flow during the intake and outlet processes in real time. When abnormal air pressure is detected, the air pressure valve is adjusted in time to accurately control the intake air pressure to reduce the rejection rate; when it is detected that the air pressure disappears and the air flow suddenly increases, it indicates that the sheet is broken, and the process can be terminated in time to shorten the process cycle; if there is no special situation, continue to monitor and enter the next cycle until the process ends. At the same time, the terminal display of the computer 13 visualizes the real-time data of air pressure and flow rate. An intuitive display of the data curve graph is convenient for product quality analysis and timely decision-making adjustment. The data curve graph is as Figure 2 shown.

[0060] Embodiment 2. This embodiment proposes a visualization method implemented based on the superplastic forming diffusion bonding product quality visualization system described in Embodiment 1. The visualization method includes the following steps:

[0061] Step 1: Grind the sheet to be formed smoothly, remove the surface oil stain, remove impurities by pickling, and clean and dry it with ethanol for later use;

[0062] Step 2: Spray the release agent on both the front and back sides of the sheet processed in Step 1, and dry it with hot air for later use.

[0063] Step 3: Spray the release agent in the die cavity, weld the inlet pipe to the air inlet of the upper die, weld the outlet pipe to the air outlet of the lower die, and install it inside the furnace body of the superplastic forming equipment according to the die position.

[0064] Step 4: Connect the inlet pipe to the pressure gauge interface of this technology, connect the pressure gauge and then connect the argon gas cylinder pressure reducing valve, and connect the outlet pipe to the flow meter of this technology.

[0065] Step 5: Check whether the functions of the lower computer controller are normal and whether it has start / stop functions, and check whether the computer visualization function is normal.

[0066] Step 6: Close the furnace door and heat the superplastic forming equipment to the process section temperature.

[0067] Step 7: Take a sheet processed in Step 2, open the furnace door, place it at the designated position of the mold, and then close the furnace door.

[0068] Step 8: After the mold reaches the set temperature, keep it warm for ten minutes, control the upper slider to press down, and hold the pressure after reaching the set pressure.

[0069] Step 9: Pressurize according to the gas pressure loading curve obtained by finite element simulation. After reaching the maximum pressure, hold the pressure for 30 minutes. The computer visualization device monitors the intake pressure and the outlet gas flow rate during the forming process in real time and autonomously judges the internal forming situation.

[0070] Step 10: If there is no abnormal situation, after the forming is completed, cool down to room temperature, then take out the sheet, and remove the sandblasting in the process section.

[0071] Step 11: If there is an abnormal situation, this technology will automatically start / stop, relieve the pressure, move the slider upward, directly take out the failed sheet, and then take another sheet processed in Step 2 and continue the forming according to Step 7.

[0072] Furthermore, during actual operation, the sheet processed in Step 1 is a high-temperature titanium alloy, and in the grinding stage of the sheet processed in Step 1, it is necessary to ensure that the sheet is smooth and has no obvious deformation. The volume percentage of the pickling liquid in Step 1 is hydrofluoric acid: nitric acid: water = 1:3:6. The pickling time in Step 1 is 1 - 5 minutes, and after pickling, it is cleaned thoroughly in ethanol.

[0073] Furthermore, the release agent in Step 2 is composed of boron nitride, and the spraying surface should be uniform.

[0074] Furthermore, the air pipe in Step 3 is a heat-resistant steel air pipe with a composition of 2520. The connection part is a threaded interface and does not require welding, while the connection with the mold is welded. The set temperature in Step 3 is 850 - 950 °C.

[0075] Furthermore, the superplastic forming gas pressure in Step 8 is set to 2 MPa, and it is gradually increased at a speed of 0.1 MPa / min. After reaching 2 MPa, hold the pressure for 30 minutes.

[0076] A method for visualizing the quality of superplastic forming and diffusion bonding products proposed in this embodiment can timely detect abnormal intake and exhaust during superplastic forming by real-time monitoring of air pressure and air flow, and adjust and control to optimize the forming process, prevent the sheet from cracking or being unable to be laminated due to incomplete forming, thereby improving the forming rate of the sheet. At the same time, when the sheet has cracked during the superplastic forming process, the experiment can be terminated in time by monitoring the abnormal air pressure to reduce the time cycle; it is also possible to provide a basis for process improvement according to the recorded air pressure data, thereby greatly shortening the process cycle of good products.

[0077] Embodiment 3. Refer to Figure 3 and Figure 4 To illustrate this embodiment, this embodiment will be described in detail with a single-layer structure of Ti60 sheet. Specifically, a method for visualizing the quality of superplastic forming and diffusion bonding products includes the following steps;

[0078] Step 1: Grind the sheet to be formed smoothly. During grinding, ensure that the sheet is smooth and has no obvious deformation. Remove the surface oil stain. Use a pickling liquid with a composition of hydrofluoric acid: nitric acid: water = 1:3:6 to pickle for 2 minutes to remove impurities, and then clean it with ethanol and dry it for standby.

[0079] Step 2: Spray boron nitride evenly on both the front and back sides of the sheet processed in Step 1, and dry it with hot air for standby.

[0080] Step 3: Weld the inlet pipe to the inlet of the upper mold, and weld the outlet pipe to the outlet of the lower mold. The gas pipe is a 2520 heat-resistant steel gas pipe. Install it inside the furnace body of the superplastic forming equipment according to the mold position. The connection with this technology is a threaded interface and does not require welding.

[0081] Step 4: Connect the inlet pipe to the air pressure gauge interface of this technology. After connecting the air pressure gauge, connect the argon gas cylinder pressure reducing valve, and connect the outlet pipe to the flow meter of this technology.

[0082] Step 5: Check whether the function of the lower computer controller is normal and whether it has a start-stop function. Check whether the computer visualization function is normal.

[0083] Step 6: Close the furnace door and heat the superplastic forming equipment to 920 °C.

[0084] Step 7: Take a sheet processed in Step 2, open the furnace door, place it at the designated position of the mold, and close the furnace door.

[0085] Step 8: After the mold reaches the set temperature, keep it warm for ten minutes, control the upper slider to press down, set the air pressure to 2 MPa, and gradually increase it at a speed of 0.1 MPa / min. After reaching 2 MPa, keep the pressure for 30 min.

[0086] Step 9: After the forming is completed without abnormal conditions, cool it down to room temperature and then take out the sheet, and remove the sandblasting in the process section.

[0087] The air pressure curve graph of this embodiment is as shown in Figure 3 the figure. The air pressure curve gradually rises to 2 MPa at a speed of 0.1 MPa / min and then remains stable. The air flow curve is as shown in Figure 4 the figure. As the air pressure continuously increases, the air flow rate also continuously increases. When the air pressure stabilizes at 2 MPa, the air flow also remains stable. As the sheet is gradually laminated, the air flow rate gradually decreases to 0. At this time, it is determined that the sheet is successfully laminated.

[0088] Embodiment 4. Refer to Figure 5 and Figure 6 to illustrate this embodiment. This embodiment takes the single-layer structure of Ti60 sheet as a detailed illustration. A specific method for visualizing the quality of a superplastic forming and diffusion bonding product includes the following steps;

[0089] Step 1: Grind the sheet to be formed smoothly. During grinding, ensure that the sheet is smooth and has no obvious deformation. Remove the surface oil stain. Use a pickling liquid with a composition of hydrofluoric acid: nitric acid: water = 1:3:6 to pickle for 2 minutes to remove impurities, and then clean it with ethanol and dry it for standby;

[0090] Step 2: Uniformly spray boron nitride on both the front and back sides of the sheet processed in Step 1, and dry it with hot air for standby.

[0091] Step 3: Weld the inlet pipe to the inlet of the upper die, and weld the outlet pipe to the outlet of the lower die. The pipe is a 2520 heat-resistant steel pipe. Install it inside the furnace body of the superplastic forming equipment according to the die position. The connection with this technology is a threaded interface and does not require welding.

[0092] Step 4: Connect the inlet pipe to the air pressure gauge interface of this technology. After connecting the air pressure gauge, connect the argon gas cylinder pressure reducing valve, and connect the outlet pipe to the flow rate gauge of this technology.

[0093] Step 5: Check whether the function of the lower computer controller is normal and whether it has the start and stop functions, and check whether the computer visualization function is normal.

[0094] Step 6: Close the furnace door and heat the superplastic forming equipment to 920 °C.

[0095] Step 7: Take a sheet processed in Step 2, open the furnace door, place it at the designated position of the die, and close the furnace door.

[0096] Step 8: After the die reaches the set temperature, keep it warm for ten minutes. Control the upper slider to press down. The initial air pressure is set to 2 MPa and gradually rises at a speed of 0.1 MPa / min. After reaching 2 MPa, keep the pressure for 10 min. Enter the middle stage of forming and adjust the air pressure to 4 MPa, and gradually rise at a speed of 0.2 MPa / min. After reaching 4 MPa, keep the pressure for 20 min.

[0097] Step 9: Detect abnormal conditions, automatically start and stop, relieve pressure, move the slider upward, and directly take out the failed sheet.

[0098] The air pressure curve of this embodiment is as Figure 5 shown. The air pressure curve gradually rises to 2 MPa at a speed of 0.1 MPa / min, then holds the pressure for 10 min, and then undergoes two pressure increases. When the air pressure rises to 3 MPa, the value suddenly changes, and the air pressure curve rapidly decreases. As Figure 6 shown, the air flow curve rapidly rises. At this time, the equipment automatically stops, and it is determined that the sheet has cracked and the process stops.

[0099] Embodiment 5. Refer to Figure 7 and Figure 8 to describe this embodiment. This embodiment takes the single-layer structure of Ti60 sheet as a detailed description. Specifically, a method for visualizing the quality of superplastic forming and diffusion bonding products includes the following steps;

[0100] Step 1: Grind the sheet to be formed smoothly. When grinding, ensure that the sheet is smooth and has no obvious deformation. Remove the surface oil stain. Use a pickling liquid with a composition of hydrofluoric acid: nitric acid: water = 1:3:6 to pickle for 2 minutes to remove impurities, and then clean it with ethanol and dry it for standby;

[0101] Step 2: Spray boron nitride evenly on both sides of the sheet processed in Step 1, and dry it with hot air for standby.

[0102] Step 3: Weld the inlet pipe to the inlet of the upper die, and weld the outlet pipe to the outlet of the lower die. The pipe is a 2520 heat-resistant steel pipe. Install it inside the furnace body of the superplastic forming equipment according to the die position. The connection with this technology is a threaded interface and does not require welding.

[0103] Step 4: Connect the inlet pipe to the air pressure gauge interface of this technology. After connecting the air pressure gauge, connect the argon gas cylinder pressure reducing valve, and connect the outlet pipe to the flow meter of this technology.

[0104] Step 5: Check whether the function of the lower computer controller is normal and whether it has the start and stop function, and check whether the computer visualization function is normal.

[0105] Step 6: Close the furnace door and heat the superplastic forming equipment to 920 °C.

[0106] Step 7: Take a sheet processed in Step 2, open the furnace door, place it at the designated position of the die, and close the furnace door.

[0107] Step 8: After the die reaches the set temperature, keep it warm for ten minutes, control the upper slider to press down, set the air pressure to 1 MPa, and gradually increase it at a speed of 0.1 MPa / min. After reaching 1 MPa, hold the pressure for 30 min.

[0108] Step 9: Detect abnormal conditions, automatically start and stop, relieve pressure, move the slider upward, and directly remove the failed sheet.

[0109] The air pressure curve of this embodiment is as Figure 7 shown. The air pressure curve gradually rises to 1 MPa at a speed of 0.1 MPa / min and then remains stable. The air flow curve is as Figure 8 shown. The air flow increases continuously as the air pressure rises. When the air pressure stabilizes at 1 MPa, the air flow also remains stable. For normal formed parts, the air flow curve gradually returns to 0 after 30 minutes, while the air flow curve of this embodiment gradually returns to 0 after 20 minutes, and it is determined that the process stops because the sheet cannot be successfully film-coated.

[0110] In summary, through the actual operation descriptions of the above Embodiment 3 to Embodiment 5, a method for visualizing the quality of superplastic forming and diffusion bonding products proposed by the present invention can timely detect abnormal conditions of air intake and exhaust during superplastic forming through real-time monitoring of air pressure and air flow, and perform regulation to optimize the forming process, prevent the sheet from cracking or being inadequately formed and unable to be film-coated, thereby improving the forming rate of the sheet. At the same time, when the sheet has cracked during the superplastic forming process, the experiment can be terminated in time through abnormal air pressure monitoring to reduce the time cycle; also, based on the recorded air pressure data, it can provide a basis for process improvement, thereby greatly shortening the good product process cycle.

[0111] The above are only the embodiments of the present invention and do not limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A quality visualization system for superplastic forming and diffusion bonding products, characterized in that, It includes a barometer, a flow meter, a lower computer controller, an industrial computer and a computer; The barometer is used to detect the air pressure data at the upper die air inlet and send it to the lower computer controller; The flow meter is used to detect the flow rate at the lower die air outlet and send the flow rate data to the lower computer controller; The lower computer controller is used to send the received air pressure and flow rate data to the industrial computer, and is also used to receive the control instructions sent by the industrial computer to adjust the air pressure at the upper die air inlet; The industrial computer is used to convert the data information received by the lower computer controller into a communication protocol and then transmit it to the computer; The computer is used to monitor the stability of air pressure and air flow during the air intake and air outlet processes in real time through a loop program. When abnormal air pressure is detected, it timely regulates the air pressure valve to accurately control the intake air pressure. When the air pressure disappears and the air flow suddenly changes, the process is terminated; if there is no special situation, it continues to monitor and enters the next cycle until the process ends.

2. The quality visualization system for superplastic forming and diffusion bonding products according to claim 1, wherein The computer can display the real-time data of air pressure and flow rate, and display the data curve graphs of air pressure and flow rate.

3. The visualization method implemented by a superplastic forming and diffusion bonding product quality visualization system as described in claim 1, characterized in that, The method is as follows: S1: Process the sheet to be formed; S2: Assemble the visualization system and heat up the superplastic forming equipment; S3: Put the processed sheet into the hot forming equipment, keep it warm for ten minutes after reaching the set temperature, control the upper slider to press down, and keep the pressure after reaching the set pressure; S4: Pressurize according to the air pressure loading curve obtained by finite element simulation, keep the pressure for 30 min after reaching the maximum pressure, and the visualization system monitors the intake air pressure and outlet air flow rate in real time during the forming process to judge the internal forming situation; S5: If there is no abnormal situation, after the forming is completed, cool it down to room temperature and then take out the sheet, and remove the sandblasting in the process section; S6: If there is an abnormal situation, it will automatically start and stop, release the pressure, the slider will move up, directly take out the failed sheet, and repeat the above steps to continue forming.

4. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 2, characterized in that, S1 specifically is: S11: Grind the sheet to be formed smoothly, remove the surface oil stain, pickling to remove impurities, and clean and dry it with ethanol; S12: Spray the release agent on both sides of the dried sheet and dry it with hot air.

5. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 3, characterized in that, The volume percentage of the pickling liquid is hydrofluoric acid: nitric acid: water = 1:3:

6.

6. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 4, characterized in that The pickling time is 1 - 5 min.

7. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 2, characterized in that, S2 specifically is: S21: Spray the release agent in the cavity of the hot forming equipment, weld the inlet pipe to the upper die air inlet, and weld the outlet pipe to the lower die air outlet; S22: Connect the inlet pipe to the barometer and then to the argon gas cylinder pressure reducing valve, and connect the outlet to the flow meter.

8. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 6, characterized in that, The release agent is boron nitride.

9. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 2, characterized in that, Heat up the superplastic forming equipment to 850 - 950 °C.

10. A method for visualizing the quality of a superplastic forming and diffusion bonding product according to claim 2, characterized in that, In S4, the superplastic forming air pressure is set to 2 MPa, and it is gradually increased at a speed of 0.1 MPa / min. After reaching 2 MPa, keep the pressure for 30 min.

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