Aging process and device for thick plate friction stir weld

Abstract

The present invention discloses an aging process and device for thick plate friction stir welds, the process comprising: S1, uniformly cutting the weld into n thin slices along the thickness direction; obtaining the pulsating aging response time for the thin slices to reach peak aging; S2, uniformly cutting the weld into n thin slices along the thickness direction; making each thin slice reach peak aging at different temperatures at the same time, obtaining a spatial gradient temperature field; S3, according to the spatial gradient temperature field, regulating the temperature field on an electromagnetic pulsating heating aging device and performing spatial gradient pulsating aging treatment on the weld. The present invention significantly improves the mechanical properties of thick plate aluminum alloy friction stir welding joints, can obtain the optimal spatial gradient temperature field by comprehensively adjusting the heating process parameters, is simple to operate and convenient to control, and realizes the possibility of industrialized production of spatial gradient pulsating aging of thick plate weld workpieces, which is of great significance to the quality improvement of welds of large / super-large thin-walled structural parts of aerospace equipment.

Description

Technical Field

[0001] The invention relates to the technical field of metal weld processing, and in particular to an aging process and device for a thick plate friction stir weld. Background Art

[0002] Friction stir welding is a welding technology widely used in aerospace and rail transportation. Its advantages include small welding deformation, high joint quality and green energy saving. However, with the continuous increase in the structural size of large / super-large high-strength aluminum alloy thin walls, the thickness of the wall plate also increases, which inevitably leads to a decrease in the connection strength of the friction stir welding weld. It is found from existing literature reports that the welding coefficient of the 2mm thick aluminum alloy friction stir welding joint is 0.83, and the welding coefficient is 0.96 after artificial aging; while the welding coefficient of the 12mm thick aluminum alloy friction stir welding joint is 0.70, and the welding coefficient is 0.83 after artificial aging; the welding coefficient of the 16mm thick friction stir welding joint is 0.53, and the welding coefficient is 0.72 after artificial aging. For large / super-large aerospace equipment, every 1% increase in the weld coefficient in the load-bearing support structure can reduce the weight of the structure by more than 1%-3%, thereby greatly increasing the payload, which is of great significance to my country's large / super-large aerospace equipment. Therefore, improving the strength of thick plate friction stir welding joints has become a key issue that needs to be solved urgently.

[0003] In the design and manufacturing process of large / super-large aerospace equipment, lightweight and high-strength materials such as aluminum alloys and titanium alloys are often used as important load-bearing structural materials, and most of the lightweight alloys are precipitation-strengthened alloys. However, during the stir friction welding process, the precipitated phase in the organization dissolves / grows, resulting in a decrease in the performance of the joint. For example, special large / super-large thin-walled structural parts such as heavy rocket fuel tanks are extremely strict with the welding environment and fixtures. It is impossible to immerse the entire structure in water or use cooling-assisted stir friction welding, which limits the implementation of measures to improve the mechanical properties of welded joints during the above welding process. In existing literature reports, the entire workpiece including the weld is often heated and aged to make the precipitated phase dissolved in the weld precipitate again to improve the strength of the weld. However, for structural parts with thick plate welds, although the overall continuous heating aging process can improve the weld strength, there are the following problems: (1) Due to the overall heating, the structural parts may be difficult to correct after heat deformation and easily scrapped, and the performance of the parent material outside the welding area may be reduced due to over-aging; (2) Compared with thin plate welds, the gradient difference of the microstructure of thick plate stir friction welding welds in the thickness direction increases, resulting in the inability to reach the peak aging at the weld surface and the weld bottom at the same time. At the same time, the market also lacks control technology and aging furnace equipment with uniform temperature space and time synchronization under ultra-large scale conditions. Therefore, it is impossible to carry out overall or local continuous aging strengthening of components after welding, resulting in large / ultra-large welded components being put into service immediately after welding. This situation seriously restricts the further improvement of the structural efficiency and performance of aerospace equipment. Summary of the invention

[0004] The present invention provides an aging process and device which can avoid the gradient difference of aging effect on the thickness of the weld caused by overall aging, obtain the optimal aging gradient temperature field on the thickness of the weld, and control the temperature field to obtain the optimal weld mechanical properties of the thick plate stir friction weld, so as to solve the technical problems mentioned in the background technology.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] An aging process for a thick plate friction stir weld comprises the following steps:

[0007] S1. Cut the weld into n thin slices uniformly along the thickness direction; perform pulsation aging treatment on all the thin slices at the same temperature for different lengths of time, and then perform mechanical property tests on the thin slices after pulsation aging treatment to obtain the relationship between the aging strength of the weld and the pulsation aging treatment time, and obtain the pulsation aging response time for the thin slice to reach peak aging;

[0008] S2, uniformly cutting the weld into n thin slices along the thickness direction; performing pulsating aging treatment on all the thin slices for the same time at different temperatures, so that each thin slice reaches peak aging at different temperatures at the same time, and obtaining a spatial gradient temperature field; in this step, the temperature of the pulsating aging treatment is adjusted according to the pulsating aging response time corresponding to the thin slice reaching the peak aging, increasing the pulsating aging temperature of the thin slice with a long pulsating aging response time reaching the peak aging, and reducing the pulsating aging temperature of the thin slice with a short pulsating aging response time reaching the peak aging, so that each thin slice reaches the peak aging at the same time;

[0009] S3. According to the spatial gradient temperature field, the temperature field is regulated on the electromagnetic pulsating heating aging device and the weld is subjected to spatial gradient pulsating aging treatment.

[0010] The design idea of ​​the above technical solution is that the present invention first performs spatial isothermal pulsating aging on the thick plate friction stir weld to obtain inconsistent peak aging response times for each weld thin slice. Then adjust the pulsating aging temperature of each weld thin slice to make the peak aging response time uniform, and obtain a temperature field in which the weld reaches peak aging simultaneously along the thickness direction. This temperature field is the spatial gradient temperature field that enables the weld to obtain the best mechanical properties. Then, the thick plate weld workpiece is subjected to spatial gradient pulsating aging treatment with this temperature field, which can effectively avoid the situation in which there are spatial differences in aging effects in the thickness direction of the weld caused by overall heating of the thick plate weld, and can also avoid the problem of plate deformation and performance changes caused by overall heating, thereby significantly improving the mechanical properties of the thick plate friction stir welding joint while ensuring the original properties of the plate.

[0011] As a further preferred embodiment of the above technical solution, in step S1, the thickness of the sheet is 0.5-6 mm, more preferably 1-2 mm. If the sheet thickness is too large, the aging effect will vary in space on the same sheet, affecting the accuracy of the temperature field and the mechanical properties of the final product; if the sheet thickness is too small, it will be difficult to process and will result in a large error in the tensile test result.

[0012] As a further preferred embodiment of the above technical solution, the weld is an aluminum alloy weld or a titanium alloy weld, and the thickness of the plate is 10 to 60 mm.

[0013] As a further preferred embodiment of the above technical solution, in step S1, when the weld is an aluminum alloy weld, the temperature for pulsating aging treatment of all thin sheets is 150~180°C, and more preferably 155~175°C; the time interval for pulsating aging treatment of all thin sheets is 0.5~6h, and more preferably 1~2h; when the weld is a titanium alloy weld, the temperature for pulsating aging treatment of all thin sheets is 480~560°C; the time interval for pulsating aging treatment of all thin sheets is 1~8h.

[0014] As a further preferred embodiment of the above technical solution, in the step S2, when the temperature of the pulsation aging treatment is adjusted according to the pulsation aging response time of the slice corresponding to the peak aging, the ratio of the change value of the temperature of the pulsation aging treatment to the change value of the pulsation aging response time to reach the peak aging is 1-15 (°C / hour), and more preferably 5-10 (°C / hour).

[0015] Based on the same technical concept, the present invention also provides an aging device for thick plate friction stir welds, including a heating system, a cooling system, a temperature monitoring system and a control system; the control system controls the heating system to heat the weld area, the control system controls the cooling system to limit the heating range of the heating system, and the temperature monitoring system is used to collect temperature information of the weld to guide the control system to control the heating system and the cooling system.

[0016] The design idea of ​​the above technical solution is that the aging device of the weld of the present invention can accurately perform heating aging treatment on the weld area by using the heating system, avoiding changes in the morphology and performance of the plate caused by large-scale heating, and at the same time cooperating with the temperature monitoring system and the cooling system to limit the heating range of the weld by the heating system, thereby forming a specific spatial gradient temperature field at the weld to achieve spatial gradient pulsating aging treatment of the weld, thereby obtaining the best weld mechanical properties.

[0017] As a further preferred embodiment of the above technical solution, the heating system and the cooling system are installed on a connecting rod and can move relative to each other; the heating system is an electromagnetic induction coil; the cooling system is a cooling device arranged outside the electromagnetic induction coil and cooling the area adjacent to the weld; the cooling device limits the heating range of the electromagnetic induction coil by releasing cooling medium.

[0018] As a further preferred embodiment of the above technical solution, the connecting rod is connected to the workbench and is movable, and the relative positions of the electromagnetic induction coil, the cooling system and the weld are controlled by the movement of the connecting rod.

[0019] As a further preferred embodiment of the above technical solution, the temperature monitoring system is used to monitor the temperature of the weld surface directly below the electromagnetic induction coil and the temperature of the base material area on both sides of the weld in real time. When the workpiece is heated by the same fixed-shape inductor, the shape of the gradient temperature field is relatively stable, that is, the temperature difference between the surface temperature and the back temperature of electromagnetic induction heating is relatively stable. Therefore, the surface temperature is connected as the characteristic temperature to the PID control system to control the heating parameters, which can meet the heating temperature control. Therefore, it is generally not necessary to monitor the temperature on the back of the weld.

[0020] The present invention has the following beneficial effects:

[0021] (1) The aging process of the thick plate friction stir weld of the present invention obtains a temperature field in which the weld reaches peak aging simultaneously along the thickness direction, and uses the temperature field to guide the weld aging process, thereby significantly improving the mechanical properties of the thick plate aluminum alloy friction stir welded joint.

[0022] (2) The aging device for thick plate friction stir welds of the present invention can obtain the optimal spatial gradient temperature field by comprehensively adjusting the heating process parameters. It is simple to operate and convenient to control, and realizes the industrial production possibility of spatial gradient pulsating aging of thick plate weld workpieces, which is of great significance to the quality improvement of welds of large / super-large thin-walled structural parts of aerospace equipment.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 This is a flow chart of the aging process for the thick plate friction stir weld of Example 1.

[0026] Figure 2 Schematic diagram of the aging process step (1) of the thick plate friction stir weld in Example 1.

[0027] Figure 3 The mechanical properties of the weld thin slice obtained in the aging process step (1) of the thick plate stir friction weld of Example 1 and the pulsating aging response time to reach the peak aging.

[0028] Figure 4 The mechanical properties of the weld sheet obtained in the aging process step (2) of the thick plate stir friction weld of Example 1 and the pulsation response time to reach peak aging.

[0029] Figure 5 The mechanical properties of the weld sheet obtained in the aging process step (2) of the thick plate stir friction weld of Example 1 and the pulsation response time to reach peak aging.

[0030] Figure 6 This is a graph showing the tensile strength of the weld of Example 1 after aging treatment in step (3).

[0031] Figure 7 The present invention is a control flow chart of the aging device for the thick plate friction stir weld.

[0032] Figure 8 This is a schematic structural diagram of the aging device for the thick plate friction stir weld of Example 2.

[0033] Fig. 9 This is an enlarged structural diagram of the electromagnetic induction coil portion of the aging device for the thick plate friction stir weld in Example 2.

[0034] Fig.10 This is a schematic structural diagram of the aging device for the thick plate friction stir weld of Example 3.

[0035] Fig.11 This is an enlarged structural diagram of the electromagnetic induction coil portion of the aging device for the thick plate friction stir weld in Example 3.

[0036] Fig.12 This is a schematic structural diagram of the aging device for the thick plate friction stir weld of Example 4.

[0037] Fig.13 This is an enlarged structural diagram of the electromagnetic induction coil portion of the aging device for the thick plate friction stir weld in Example 4.

[0038] Fig.14 This is a schematic structural diagram of the aging device for the thick plate friction stir weld of Example 5.

[0039] Fig.15 This is an enlarged structural diagram of the electromagnetic induction coil portion of the aging device for the thick plate friction stir weld of this embodiment 5.

[0040] Fig.16 This is a schematic structural diagram of the aging device for the thick plate friction stir weld of Example 6.

[0041] Fig.17 This is an enlarged structural diagram of the electromagnetic induction coil portion of the aging device for the thick plate friction stir weld in Example 6.

[0042] Legend:

[0043] 1. Electromagnetic induction coil; 11. Medium frequency power supply system; 2. Cooling device; 3. Infrared temperature sensor; 4. Welding structure; 41. Welding seam; 42. Welding seam adjacent area; 5. Connecting rod; 6. Workbench; 61. Workbench drive system; 62. Workbench control system; 63. Connecting rod drive device; 7. PID control system. DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0045] Embodiment 1:

[0046] like Figure 1As shown, the aging process of the thick plate friction stir weld in this embodiment is used to process 18mm aluminum alloy welds. According to the organizational characteristics, the friction stir weld can be divided into a stirring zone (SZ), a thermomechanical affected zone (TMAZ), a heat affected zone (HAZ) and a base material (BM) from the center of the weld to the base material. The advancing side (AS) and the retreating side (RS) are divided into two sides by the center of the friction stir weld, which is determined by whether the rotation direction and the advancing direction of the welding tool are consistent. On the advancing side of the weld, the rotation direction of the welding tool is consistent with the advancing direction of the welding tool; while on the retreating side of the weld, it is the opposite. The aging process mainly includes the following steps:

[0047] S1, such as Figure 2 As shown in the figure, the weld is evenly cut into 8 thin slices along the thickness direction, numbered from 0 to 7 layers from top to bottom, and the thickness of each weld is 1.9 mm; all weld slices are subjected to pulsation aging at different times using a pulsating temperature of 165°C, with a time interval of 0.5 to 2 hours; the mechanical properties of all weld slices are tested, and the weld aging and response time are obtained by drawing a graph. The results are shown in Figure 3 As shown in the figure, the peak aging time of the 1st and 2nd layer sheets is 2 hours and 3 hours respectively, while the peak aging time of the 3rd to 4th layer sheets is 4 hours, and the peak aging time of the 5th to 6th layer sheets is 5 hours. It can be found that the response time of reaching the peak aging of each sheet along the thickness direction is not uniform and is distributed in a gradient.

[0048] S2. The weld is evenly cut into 8 thin slices along the thickness direction, which are numbered from 0 to 7 from top to bottom, and the thickness of each weld is 1.9 mm; each layer of weld thin slices is subjected to pulsation aging at different temperatures, so that each layer of weld thin slices reaches peak aging at the same aging time. Based on the peak aging response time of each thin slice under the spatial isothermal pulsation aging temperature, the pulsation aging temperature of the weld thin slice with a longer response time is increased, and the pulsation aging temperature of the weld thin slice with a shorter response time is reduced, so as to obtain the aging treatment temperature gradient selection of this embodiment, such as Figure 4 As shown in the figure, it is the spatial gradient temperature field. After adjustment, all weld slices were subjected to pulsation aging at different temperatures. All weld slices were tested for mechanical properties, and finally the relationship between the peak aging of each layer of weld and the corresponding time was drawn, as shown in the figure below. Figure 4 It can be seen that the peak aging response time of each weld thin film under the gradient temperature field is 5 hours.

[0049] As a comparison, this embodiment uses different temperature gradients to perform pulse aging on different pulse temperatures of each layer of weld thin film. The aging treatment temperature gradient is selected as follows: Figure 5 As shown in the figure, all weld thin slices were subjected to mechanical property tests, and finally the relationship between the peak aging of each layer of weld and the corresponding time was plotted, as shown in the figure. Figure 5 As shown in the figure, the peak aging response time from the top of the weld to the bottom of the weld differs by 6.5 hours. It can be seen that the response time of the weld to peak aging is more uneven along the thickness direction.

[0050] S3. Use the spatial gradient temperature field obtained in S2 to perform spatial gradient pulsation aging strengthening on the weld.

[0051] As a comparison, the spatial gradient temperature field of the comparative aging treatment in S2 was used to perform spatial gradient pulsating aging strengthening on the friction weld. The mechanical properties of all the welds obtained were tested. The results are as follows: Figure 6 shown.

[0052] Embodiment 2:

[0053] Figure 7 FIG. 1 is a control flow chart of the aging device for the thick plate friction stir weld of the present invention. Figure 8-Figure 9 As shown, the aging device for the thick plate friction stir weld of this embodiment includes an electromagnetic induction coil 1, a medium frequency power supply system 11 (the electromagnetic induction frequency is 10~30KHz, the induced current is 5~30KA, and the induced voltage is 380V), a cooling device 2 for cooling the weld adjacent area 42, an infrared temperature sensor 3, a PID control system 7, a workbench 6, a workbench drive system 61, a workbench control system 62, a connecting rod drive device 63 and a connecting rod 5.

[0054] The welding structure 4 is placed on the workbench 6; the connecting rod 5 is connected to the connecting rod driving device 63, and the workbench control system 62 controls the connecting rod driving device 63 to realize the movement of the connecting rod 5 in the vertical direction (the scheme selected in this embodiment and other embodiments is that the connecting rod 5 is fixed on a slider of the connecting rod driving device 63, and the slider can slide along a vertical slide bar of the connecting rod driving device 63, and the workbench control system 62 controls the motor of the connecting rod driving device 63 to drive the screw rod to rotate, thereby driving the slider to move vertically; other reasonable transmission control methods can also be selected according to actual conditions and needs); the rectangular electromagnetic induction coil 1 and the cooling device 2 are connected to the connecting rod 5, and the two can move relative to each other, and the PID control system 7 controls the horizontal extension of the connecting rod 5. The PID control system 7 controls the intermediate frequency power supply system 11 to supply power to the electromagnetic induction coil 1, so that the electromagnetic induction coil 1 heats the weld 41 area, and the cooling device 2 is used to limit the heating range of the electromagnetic induction coil 1. The infrared temperature sensor 3 is connected to the PID control system 7, and is used to monitor the temperature of the weld 41 surface directly below the electromagnetic induction coil 1 and the temperature of the parent material area on both sides of the weld 41. The cooling device 2 is a nozzle for spraying cooling medium, and the cooling medium is compressed air and liquid nitrogen. The PID control system 7 controls the flow rate of the cooling medium sprayed by the cooling device 2. The workbench control system 62 controls the workbench driving system 61 to realize the horizontal movement of the workbench 6 and the welding structure 4. The workbench control system 62 is also connected to the PID control system 7 (the solution selected in this embodiment and other embodiments is to control the electric operation to drive the gear to rotate through the workbench control system 62, and the gear then drives the movement of the workbench 6 with the edge provided with a locking tooth that cooperates with the gear. By designing the shape of the workbench 6, the horizontal movement or rotation of the workbench 6 can be realized).

[0055] When the aging device for thick plate friction stir welds of this embodiment is used to perform aging treatment on thick plate friction stir welds, the steps of Example 1 are followed, and the induction coil is subjected to a cyclic scanning electromagnetic induction heating spatial gradient pulsation aging treatment along the direction of the weld 41 for a cumulative 5 hours, so that each area in the weld 41 reaches peak aging at the same time. During the aging treatment, the distance between the cooling device 2 and the weld 41 is 10~20mm, the flow rate of the cooling medium is 0.5~2L / min, and the distance between the electromagnetic induction coil 1 and the weld 41 is 4mm.

[0056] Embodiment 3:

[0057] like Fig.10 and Fig.11 As shown, the aging device for the thick plate friction stir weld of this embodiment includes an electromagnetic induction coil 1, a medium frequency power supply system 11 (the electromagnetic induction frequency is 10~30KHz, the induced current is 5~30KA, and the induced voltage is 380V), a cooling device 2 for cooling the adjacent area 42 of the weld, an infrared temperature sensor 3, a PID control system 7, a workbench 6, a workbench drive system 61, a workbench control system 62, a connecting rod drive device 63 and a connecting rod 5. The structure is basically the same as that of Example 2, except that the applicable welding structure 4 is a longitudinal weld 41, the setting direction of the cooling device 2 and the electromagnetic induction coil 1 of this embodiment matches the weld 41, and the present embodiment adopts a rotary drive method to realize the rotation of the workbench 6 and the welding structure 4.

[0058] Embodiment 4:

[0059] like Fig.12 and Fig.13 As shown, the aging device for the thick plate friction stir weld of this embodiment includes an electromagnetic induction coil 1, a medium frequency power supply system 11 (the electromagnetic induction frequency is 10~30KHz, the induced current is 5~30KA, and the induced voltage is 380V), a cooling device 2 for cooling the adjacent area 42 of the weld, an infrared temperature sensor 3, a PID control system 7, a workbench 6, a workbench drive system 61, a workbench control system 62, a connecting rod drive device 63 and a connecting rod 5. The structure is basically the same as that of Example 2, except that the applicable welding structure 4 is an annular weld 41, the setting direction of the cooling device 2 and the electromagnetic induction coil 1 of this embodiment matches the weld 41, and the present embodiment adopts a rotary drive method to realize the rotation of the workbench 6 and the welding structure 4.

[0060] Embodiment 5:

[0061] like Fig.14 and Fig.15As shown, the aging device for the thick plate friction stir weld of this embodiment includes an electromagnetic induction coil 1, a medium frequency power supply system 11 (the electromagnetic induction frequency is 10~30KHz, the induced current is 5~30KA, and the induced voltage is 380V), a cooling device 2 for cooling the adjacent area 42 of the weld, an infrared temperature sensor 3, a PID control system 7, a workbench 6, a workbench drive system 61, a workbench control system 62, a connecting rod drive device 63 and a connecting rod 5. Its structure is basically the same as that of the device embodiment 2, except that the electromagnetic induction coil 1 is used to perform aging treatment on the surface of the longitudinal weld 41 of the heavy rocket fuel tank. The setting direction of the cooling device 2 and the electromagnetic induction coil 1 of this embodiment matches the weld 41, and the electromagnetic induction coil 1 performs a cyclic scanning electromagnetic induction heating spatial gradient pulsating aging treatment along the weld 41 area. This embodiment adopts a rotating drive method to realize the rotation of the workbench 6 and the welded structural member 4.

[0062] Embodiment 6:

[0063] like Fig.16 and Fig.17 As shown, the aging device for the thick plate friction stir weld of this embodiment includes an electromagnetic induction coil 1, a medium frequency power supply system 11 (the electromagnetic induction frequency is 10~30KHz, the induced current is 5~30KA, and the induced voltage is 380V), a cooling device 2 for cooling the adjacent area 42 of the weld, an infrared temperature sensor 3, a PID control system 7, a workbench 6, a workbench drive system 61, a workbench control system 62, a connecting rod drive device 63 and a connecting rod 5. Its structure is basically the same as that of the device embodiment 2, except that the electromagnetic induction coil 1 is used to perform aging treatment on the surface of the annular weld 41 of the heavy rocket fuel tank. The setting direction of the cooling device 2 and the electromagnetic induction coil 1 of this embodiment matches the weld 41, and the electromagnetic induction coil 1 performs a cyclic scanning electromagnetic induction heating spatial gradient pulsating aging treatment along the weld 41 area. This embodiment adopts a rotating drive method to realize the rotation of the workbench 6 and the welded structural member 4.

[0064] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

[0065] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An aging process for thick plate friction stir welds, characterized in that: The following steps are involved: S1. Cut the weld into n thin slices uniformly along the thickness direction; perform pulsation aging treatment on all the thin slices at the same temperature for different lengths of time, and then perform mechanical property tests on the thin slices after pulsation aging treatment to obtain the relationship between the aging strength of the weld and the pulsation aging treatment time, and obtain the pulsation aging response time for the thin slice to reach peak aging; S2, uniformly cutting the weld into n thin slices along the thickness direction; performing pulsating aging treatment on all the thin slices for the same time at different temperatures, so that each thin slice reaches peak aging at different temperatures at the same time, and obtaining a spatial gradient temperature field; in this step, the temperature of the pulsating aging treatment is adjusted according to the pulsating aging response time corresponding to the thin slice reaching the peak aging, increasing the pulsating aging temperature of the thin slice with a long pulsating aging response time reaching the peak aging, and reducing the pulsating aging temperature of the thin slice with a short pulsating aging response time reaching the peak aging, so that each thin slice reaches the peak aging at the same time; S3. According to the spatial gradient temperature field, the temperature field is regulated on the electromagnetic pulsating heating aging device and the weld is subjected to spatial gradient pulsating aging treatment.

2. The aging process of thick plate friction stir weld according to claim 1, characterized in that: In step S1, the thickness of the sheet is 0.5-6 mm.

3. The aging process for thick plate friction stir weld according to claim 1, characterized in that: The weld is an aluminum alloy weld or a titanium alloy weld, and the thickness of the plate is 10-60 mm.

4. The aging process for thick plate friction stir weld according to claim 3, characterized in that: In step S1, when the weld is an aluminum alloy weld, the temperature for pulsating aging treatment of all thin sheets is 150-180°C; the time interval for pulsating aging treatment of all thin sheets is 0.5-6h; when the weld is a titanium alloy weld, the temperature for pulsating aging treatment of all thin sheets is 480-560°C; the time interval for pulsating aging treatment of all thin sheets is 1-8h.

5. The aging process for thick plate friction stir weld according to any one of claims 1 to 4, characterized in that: In the step S2, when the temperature of the pulsation aging treatment is adjusted according to the pulsation aging response time of the slice corresponding to the peak aging, the ratio of the change value of the temperature of the pulsation aging treatment to the change value of the pulsation aging response time to the peak aging is 1-15°C / hour.

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