Friction stir welding seam structure regulation and control device and method

Abstract

The invention provides a friction stir welding seam structure regulation and control device and method, and belongs to the technical field of welding equipment.The friction stir welding seam structure regulation and control device comprises a main shaft, a workbench and a regulation and control system, and a stirring head is fixed to the bottom end of the main shaft and located over the workbench; the regulation and control system comprises a laser vibration meter, an infrared thermometer, an ultrasonic vibration excitation body and a flow controller, the laser vibration meter and the infrared thermometer are fixed to the two sides of the main shaft through a main shaft support, the ultrasonic vibration excitation body is vertically installed between the main shaft support and the workbench, one end of the flow controller is connected with the water cooling machine, and the other end of the flow controller is connected with the water cooling machine. And the other end is connected with a liquid inlet of the cooling cavity in the main shaft bracket. The temperature and amplitude frequency of the welding seam can be dynamically collected and analyzed in real time, and parameters are adjusted and optimized in real time through computer-aided calculation processing, so that the uniformity of the welding seam structure is adjusted and controlled, and it is guaranteed that the strength of the welding seam reaches the standard.

Description

Technical Field

[0001] The invention belongs to the technical field of welding equipment, and in particular relates to a device and method for controlling weld structure of friction stir welding. Background Art

[0002] With the continuous improvement of vehicle lightweighting and strength requirements, higher requirements are placed on the manufacturing of automobile rims. Traditional cast rims have disadvantages such as low strength, heavy weight, and poor heat conductivity; while forged rims have the defects of high cost and difficult maintenance. Therefore, an advanced connection technology is needed to connect the rims axially.

[0003] Since its introduction, friction stir welding technology has been rapidly developed and widely used. Using friction stir welding to weld the rim axially can not only reduce processing time and consumables costs, but also help improve the quality of the welded joint. In the friction stir welding process of the rim, the welding heat source mainly comes from the friction heat generated by the stirring head shoulder and the material and the plastic deformation heat of the material. Therefore, the more friction heat is generated and the greater the plastic deformation, the higher the welding temperature. Therefore, within a certain range, the temperature and amplitude frequency of the weld have a strong influence on the microstructure and strength of the weld. In actual welding operations, factors such as the thickness error of the welding plate and the flatness of the workbench surface will lead to changes in the welding process, thereby causing changes in the temperature peak and the amplitude frequency peak, and ultimately leading to an increase in the unevenness of the weld joint quality.

[0004] During the friction stir welding process, the temperature and amplitude frequency of the weld change dynamically. Existing friction stir welding equipment cannot adjust the temperature and amplitude frequency in real time, so the welding quality cannot be guaranteed. Summary of the invention

[0005] In view of the defects or shortcomings in the prior art, the present invention provides a device and method for controlling the weld structure of a friction stir welding seam, which can dynamically collect and analyze the temperature and amplitude frequency of the weld in real time, and adjust and optimize the parameters in real time through computer-aided calculation and processing, so as to control the uniformity of the weld structure and ensure that the strength of the weld meets the standard.

[0006] To achieve the above object, the present invention adopts the following technical solution: In a first aspect, an embodiment of the present invention provides a friction stir welding weld structure control device, comprising a spindle, a workbench and a control system, wherein a stirring head is fixed to the bottom end of the spindle, and the stirring head is located directly above the workbench; The control system includes a laser vibrometer, an infrared thermometer, an ultrasonic exciter and a flow controller, wherein the laser vibrometer and the infrared thermometer are fixed on both sides of the main shaft through a main shaft bracket, the ultrasonic exciter is located inside the workbench and is connected to the main shaft bracket through a fixed bracket, the ultrasonic exciter is coaxially arranged with the main shaft, one end of the flow controller is connected to a water cooler, and the other end is connected to the liquid inlet of the cooling cavity in the fixed bracket through a conduit.

[0007] Furthermore, the main shaft is arranged at the bottom of the gantry beam, a linear module is arranged at the bottom of the gantry beam, and the main shaft is fixedly connected to the linear module.

[0008] Furthermore, the workbench is slidably connected to the base, and an extrusion clamp is fixed on the upper surface of the workbench.

[0009] Furthermore, the laser vibrometer is arranged below the spindle support and on one side of the welding direction, and moves synchronously with the spindle to collect vibration frequency data generated by the stirring head on the workpiece.

[0010] Furthermore, the infrared thermometer is arranged below the spindle support on the side opposite to the welding direction, and moves synchronously with the spindle to collect temperature data of the weld.

[0011] Furthermore, one end of the ultrasonic exciter is connected to an ultrasonic generator to convert high-frequency electrical signals into mechanical vibrations to control the amplitude and frequency.

[0012] Furthermore, the control system also includes a signal auxiliary processing computer, and the ultrasonic generator and the water cooler are both electrically connected to the signal auxiliary processing computer.

[0013] Furthermore, the infrared thermometer and the laser vibrometer are both connected to the signal auxiliary processing computer via a data transmission module.

[0014] In a second aspect, an embodiment of the present invention further provides a method for controlling the structure of a friction stir welding weld, using a friction stir welding weld structure control device as described above, comprising the following steps: Start the ultrasonic generator, water cooler, laser vibrometer and infrared thermometer, adjust the irradiation angle of the infrared thermometer and laser vibrometer, aim the infrared thermometer at the weld area, and aim the laser vibrometer at the weld surface area; According to the geometric shapes of the workpiece and the stirring head and the welding requirements, a numerical control program is compiled in the signal-assisted processing computer, and the welding process parameters, temperature field peak value and ultrasonic vibration parameter range are input into the numerical control program; During the welding process of the stirring head moving, the real-time temperature data of the weld collected by the infrared thermometer is sent to the signal auxiliary processing computer through the data transmission module. The signal auxiliary processing computer displays the real-time temperature data and compares the real-time temperature data with the peak value of the temperature field. If the real-time temperature data is higher than the peak value of the temperature field, the coolant flow rate in the cooling cavity is increased; if the real-time temperature data is lower than or equal to the peak value of the temperature field, the coolant flow rate in the cooling cavity is reduced, and finally the temperature of the weld is kept stable; The real-time amplitude and frequency data of the weld collected by the laser vibrometer is sent to the signal auxiliary processing computer through the data transmission module. The signal auxiliary processing computer displays the real-time amplitude and frequency data and compares the real-time amplitude and frequency data with the expected amplitude and frequency value. If the real-time amplitude and frequency data is higher than the expected amplitude and frequency value, the ultrasonic generator is controlled to reduce the amplitude and frequency; if the real-time amplitude and frequency data is lower than the expected amplitude and frequency value, the ultrasonic generator is controlled to increase the amplitude and frequency, so as to finally keep the amplitude and frequency of the weld stable.

[0015] Furthermore, the weld temperature and amplitude frequency are adjusted synchronously.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention arranges a laser vibrometer and an infrared thermometer on both sides of the main shaft, collects real-time amplitude and frequency data for processing and analysis, and adjusts the temperature and amplitude frequency of the weld through an ultrasonic exciter and a flow controller. Maintaining the temperature and amplitude frequency of the weld within a smaller fluctuation space not only helps to eliminate the participating stress in the weld, but also can improve the uniformity and consistency of the structure of the stir friction welding weld, and effectively improve the process quality of the stir friction welding.

[0017] 2. The present invention can not only guarantee the processing technology requirements to the maximum extent, but also detect and handle abnormal temperatures in a timely manner by comparing and controlling the real-time temperature data of the weld with the peak value of the temperature field.

[0018] 3. The present invention monitors the weld temperature and amplitude frequency, analyzes the obtained feedback signal through auxiliary computer coupling processing, and then re-optimizes the coolant flow rate and the vibration frequency of the ultrasonic vibration, so that the change of the weld during the stir friction welding process is within the standard range, ensuring the stability of the weld structure after welding.

[0019] 4. The present invention adopts a data transmission module to send and receive signals, that is, through a wireless communication protocol, any signal receiving end with the same protocol, including mobile phones and other devices, can be used to collect and process temperature and amplitude frequency data, making the data real-time, observable and shareable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a schematic diagram of the overall structure of the friction stir welding equipment in the first embodiment of the present invention; Figure 2 A diagram showing the position relationship between the workbench and the squeeze clamp in the first embodiment of the present invention; Figure 3 This is a diagram showing the connection relationship between the main body of the friction stir welding equipment and the control system in the first embodiment of the present invention; Figure 4 This is a diagram showing the internal structure of a workbench in Embodiment 1 of the present invention; Among them, 1. column; 2. gantry beam; 3. base; 4. workbench; 5. drive motor; 6. spindle bracket; 7. spindle; 8. stirring head; 9. gasket; 10. pressure block; 11. extrusion clamp; 12. rim workpiece; 13. infrared thermometer; 14. ultrasonic exciter; 15. ultrasonic generator; 16. water cooler; 17. laser vibrometer; 18. flow controller; 19. cooling cavity; 20. data transmission module; 21. signal auxiliary processing computer. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Embodiment 1 A typical implementation of the present invention is as follows Figure 1 and Figure 2 As shown, a friction stir welding weld structure control device includes a friction stir welding equipment body and a control system. The friction stir welding equipment body includes a column 1. Two columns 1 are provided. The two columns 1 are both n-shaped. The tops of the two columns 1 are connected by a gantry beam 2. The two ends of the gantry beam 2 are respectively fixedly connected to the two columns 1. A linear module is fixed to the bottom of the gantry beam 2. The linear module is arranged along the length direction of the gantry beam 2. A main shaft 7 is fixedly connected to the slider of the linear module, so that the main shaft 7 can be moved along the length direction of the gantry beam 2 by using the linear module. A stirring head 8 is connected to the bottom end of the main shaft 7. The main shaft 7 can drive the stirring head 8 to rotate, and the stirring head 8 is used to stir friction welding the workpiece.

[0023] A lifting screw and a lifting motor are arranged inside the main shaft 7. The lifting motor is connected to the lifting screw through a worm gear. The lifting screw drives the main shaft 7 to move up and down, thereby adjusting the welding height of the stirring head. This is the prior art and will not be described in detail here.

[0024] A base 3 is arranged directly below the spindle 7, and guide rails are symmetrically arranged on the upper surface of the base 3. A workbench 4 is arranged above the base 3, and the workbench 4 is slidably connected to the base 3 through the guide rails. A driving motor 5 is arranged on one side of the base 3, and the output shaft of the driving motor 5 is connected to the workbench 4 through a screw rod, so that the driving motor 5 is used to drive the workbench 4 to slide on the base 3. The moving direction of the workbench 4 is perpendicular to the moving direction of the spindle 7, that is, the workbench 4 slides along the X-axis direction, and the spindle 7 slides along the Y-axis direction, so that it is convenient to weld the workpiece placed on the workbench 4.

[0025] An extrusion clamp 11 is fixed on the upper surface of the workbench 4 for clamping a rim workpiece 12 . In this embodiment, the material of the rim workpiece 12 is a heat-treated 6083 aluminum alloy.

[0026] Before welding, a 5 mm thick rolled aluminum plate is punched into a hollow circular workpiece, a high temperature alloy gasket 9 is placed at the bottom of the position to be welded, and then the workpiece is mounted on the workbench 4, and pressure blocks 10 are placed on both sides of the workpiece surface 10 mm away from the center position. The extrusion clamp 11 is fixed to the workbench 4 by bolts, and the extrusion end is used to tighten the workpiece by the extrusion pressure block. Eight bolt through holes are inclined at the upper end of the workpiece, and the sides of the workpiece are tightened by bolts to prevent the stir friction welding from stretching the workpiece to both ends during welding.

[0027] After the welding workpiece is clamped and fixed, the stirring head 8 is inserted into the main shaft 7 and tightened. The stirring head 8 rotates with the main shaft 7 to weld the workpiece. The main shaft 7 moves in the Y-axis and Z-axis directions and drives the stirring head 8 to rotate. The worktable 4 moves in the X-axis direction on the base 3.

[0028] Perform tool setting operation and set the welding program so that the moving track of the stirring head 8 is at the center of the area to be welded. Adjust the welding parameters within the standardized range, including the rotation speed w, welding speed v, welding start-stop time t and downward pressure h, etc. These parameters remain unchanged.

[0029] like Figure 3 and Figure 4 As shown, the control system includes a laser vibrometer 17, an infrared thermometer 13, an ultrasonic exciter 14, a flow controller 18 and a signal auxiliary processing computer 21, wherein the laser vibrometer 17 and the infrared thermometer 13 are fixed on both sides of the spindle 7 through the spindle bracket 6, the laser vibrometer 17 is arranged below the spindle bracket 6 on one side of the welding direction, and moves synchronously with the spindle 7 to collect the vibration frequency data generated by the stirring head 8 on the workpiece, and the infrared thermometer 13 is arranged below the spindle bracket 6 on one side of the welding direction, and moves synchronously with the spindle 7 to collect the temperature data of the weld.

[0030] A fixed bracket is provided at one end of the spindle bracket 6, and the fixed bracket is an L-shaped structure. The fixed bracket includes a cross bar and a longitudinal bar. The longitudinal bar is vertically arranged to the spindle bracket 6, and the cross bar is parallel to the spindle bracket 6. A cavity is provided inside the workbench 4, and one side of the cavity is open. The cross bar is inserted into the cavity from one side of the open end of the workbench 4. An ultrasonic exciter 14 is fixedly connected to the cross bar. The ultrasonic exciter 14 is located directly below the spindle 7. When the spindle 7 moves, the ultrasonic exciter 14 moves with the spindle 7 driven by the fixed bracket, thereby ensuring the coaxiality of the ultrasonic exciter 14 and the spindle 7.

[0031] One end of the ultrasonic exciter 14 is connected to an ultrasonic generator 15, which is connected to a signal auxiliary processing computer 21 to convert high-frequency electrical signals into mechanical vibrations to control the amplitude and frequency, and to achieve the ultrasonic vibration effect on the weldment through the vibration conduction of the thin wall to control the amplitude and frequency. A cooling cavity 19 is also provided inside the fixed bracket, and the cooling cavity 19 is located on one side of the ultrasonic exciter 14. By introducing a coolant into the cooling cavity 19, the temperature after welding is controlled.

[0032] One end of the flow controller 18 is connected to the water cooler 16 to the signal auxiliary processing computer 21, and the other end is connected to the liquid inlet of the cooling cavity 19 in the fixed bracket through a conduit to feedback and regulate the size of the water flow and perform temperature control.

[0033] The infrared thermometer 13 and the laser vibrometer 17 are connected to the signal auxiliary processing computer 21 through the data transmission module 20, so as to send the collected real-time temperature data and real-time amplitude and frequency data to the signal auxiliary processing computer 21. During the welding process, the signal auxiliary processing computer 21 couples the real-time temperature data with the real-time amplitude and frequency data through a built-in algorithm, and compares the coupling result with the expectation to determine whether the real-time temperature and amplitude frequency need to be adjusted.

[0034] If the temperature and amplitude frequency need to be adjusted, the signal auxiliary processing computer 21 outputs the parameters to the flow controller 18 and the ultrasonic generator 15 to adjust the real-time temperature and real-time amplitude frequency, and then the infrared thermometer 13 and the laser vibrometer 17 detect the data transmitted to the data transmission module 20 again to determine whether the expected value is reached. If not, the above actions are repeated until the real-time temperature and real-time amplitude frequency reach the expected value and the parameter change is stopped.

[0035] In this embodiment, the infrared thermometer 13 is connected to the lower side of the spindle bracket 6 by bolts on the side opposite to the welding direction. The model of the infrared thermometer 13 is STE-8-722. It can establish the relationship between the output voltage of the infrared thermometer 13 and the radiation amount received by the infrared thermometer 13, and draw the temperature field around the welding surface. The infrared thermometer 13 may include a thermopile sensor, a low-noise amplifier, an A / D conversion module, a single-chip microcomputer, an LCD display module and a power supply module, and is a common infrared thermometer on the market.

[0036] The laser vibrometer 17 is connected to the bottom of the spindle bracket 6 by bolts and is located on the side opposite to the welding direction. The model of the laser vibrometer 17 is PSV-500, which can measure the vibration of the object by using the laser Doppler effect and draw the amplitude frequency curve of the welding surface. The internal structure of the laser vibrometer 17 mainly includes an optical system, a signal processor, a scanning component and a supporting software analysis system. It is a common laser vibrometer on the market.

[0037] The internal sensors of the infrared thermometer 13 and the laser vibrometer 17 convert the detected welding conditions into electrical signals, and then transmit the electrical signals to the data transmission module 20 through the data line. The laser vibrometer 17 transmits the amplitude frequency of the workpiece surface at the welding position to the data transmission module 20, and the infrared thermometer 13 transmits the collected weld temperature data to the data transmission module 20. Finally, the two parameters are input together through the data transmission module 20 to the signal auxiliary processing computer 21 for data processing.

[0038] The data transmission module is used to send and receive signals, that is, through the wireless communication protocol, any signal receiving end with the same protocol, including mobile phones and other devices, can be used to collect and process temperature and amplitude frequency data, making the data real-time, observable and shareable.

[0039] During the welding process, the ultrasonic exciter 14 is always at the bottom of the workpiece molten pool, and the cooling cavity 19 maintains a fixed distance from the molten pool to ensure that the auxiliary process acts at a fixed position; the infrared thermometer 13 and the laser vibrometer 17 also remain stationary after adjusting the detection angle to ensure that the detection position remains unchanged; so that the auxiliary process means and the detection means are both located at the weld molten pool position.

[0040] Since the different amplitude frequencies generated by the ultrasonic generator 15 will affect the molten pool temperature, the coolant flow rate in the cooling cavity 19 is affected by the ultrasonic vibration parameters, and different cooling rates will also change the optimal ultrasonic vibration parameters, so the two parameters are coupled to obtain the expected value. Under the expected value parameters, the microstructure and mechanical properties of the weld are optimal, and the expected value is set into the program in the signal auxiliary processing computer 21; When the infrared thermometer 13 and the laser vibrometer 17 transmit the signals to the signal auxiliary processing computer 21 for the first time, the expected values ​​of the pre-set temperature and amplitude frequency are compared respectively. If the detected temperature and amplitude frequency data are lower than the expected values, the signal auxiliary processing computer 21 controls the ultrasonic generator 15 to increase the amplitude frequency and controls the flow controller 18 to reduce the flow to slow down the speed of the cold zone; on the contrary, if the detected temperature and amplitude frequency data are lower than the expected values, the signal auxiliary processing computer 21 controls the ultrasonic generator 15 to reduce the amplitude frequency and controls the flow controller 18 to increase the flow to speed up the cold zone until the amplitude frequency and temperature parameters reach the expected values. The signal auxiliary processing computer 21 maintains the dynamic balance of the amplitude frequency and temperature parameters with the expected values ​​as the target through the set program.

[0041] By monitoring the weld temperature and amplitude frequency, the obtained feedback signal is analyzed through auxiliary computer coupling processing, and then the coolant flow rate and the vibration frequency of the ultrasonic vibration are re-optimized, so that the changes in the weld during the stir friction welding process are within the standard range, ensuring the stability of the weld structure after welding.

[0042] The results show that under the dynamic control of the auxiliary process, the temperature and amplitude frequency of the weld are maintained within a smaller fluctuation space. Compared with the weld with fixed temperature and amplitude frequency, the weld under dynamic control has better microstructure uniformity, smaller tensile strength tolerance of each part of the weld, and enhanced discreteness of fatigue strength.

[0043] Embodiment 2 This embodiment provides a method for controlling the structure of a friction stir welding weld, using a friction stir welding weld structure control device as described in the first embodiment, including the following steps: Start the ultrasonic generator 15, the water cooler 16, the laser vibrometer 17 and the infrared thermometer 13, adjust the irradiation angles of the infrared thermometer 13 and the laser vibrometer 17, aim the infrared thermometer 13 at the weld area, and aim the laser vibrometer 17 at the weld surface area; According to the geometric shapes of the workpiece and the stirring head 8 and the welding requirements, a numerical control program is compiled in the signal auxiliary processing computer 21, and welding process parameters, temperature field peak value and ultrasonic vibration parameter range are input into the numerical control program. The welding process parameters include rotation speed w, welding speed v, welding start and stop time t and downward pressure h, and the workpiece is welded; During the moving welding process of the stirring head 8, the real-time temperature data of the weld collected by the infrared thermometer 13 is sent to the signal auxiliary processing computer 21 through the data transmission module 20. The signal auxiliary processing computer 21 displays the real-time temperature data and compares the real-time temperature data with the peak value of the temperature field. If the real-time temperature data is higher than the peak value of the temperature field, the flow rate of the coolant in the cooling cavity 19 is increased; if the real-time temperature data is lower than or equal to the peak value of the temperature field, the flow rate of the coolant in the cooling cavity 19 is reduced, and finally the temperature of the weld is kept stable; By comparing and controlling the real-time temperature data of the weld and the peak value of the temperature field, it is possible to guarantee the processing requirements to the maximum extent and to detect and handle abnormal temperatures in a timely manner. The real-time amplitude and frequency data of the weld seam collected by the laser vibrometer 17 is sent to the signal auxiliary processing computer 21 through the data transmission module 20. The signal auxiliary processing computer 21 displays the real-time amplitude and frequency data and compares the real-time amplitude and frequency data with the expected amplitude and frequency value. If the real-time amplitude and frequency data is higher than the expected amplitude and frequency value, the ultrasonic generator 15 is controlled to reduce the amplitude and frequency; if the real-time amplitude and frequency data is lower than the expected amplitude and frequency value, the ultrasonic generator 15 is controlled to increase the amplitude and frequency, so as to finally keep the amplitude and frequency of the weld seam stable. The weld temperature and amplitude frequency must be adjusted synchronously. By continuously adjusting the weld temperature and amplitude frequency parameters, the two can achieve a dynamic balance effect, ensuring that the weld temperature and amplitude frequency are within a stable range.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A friction stir welding weld structure control device, characterized in that: It includes a main shaft, a workbench and a control system. A stirring head is fixed at the bottom end of the main shaft, and the stirring head is located directly above the workbench. The control system includes a laser vibrometer, an infrared thermometer, an ultrasonic exciter and a flow controller, wherein the laser vibrometer and the infrared thermometer are fixed on both sides of the main shaft through a main shaft bracket, the ultrasonic exciter is located inside the workbench and is connected to the main shaft bracket through a fixed bracket, the ultrasonic exciter is coaxially arranged with the main shaft, one end of the flow controller is connected to a water cooler, and the other end is connected to the liquid inlet of the cooling cavity in the fixed bracket through a conduit.

2. A friction stir welding weld structure control device as claimed in claim 1, characterized in that: The main shaft is arranged at the bottom of the gantry cross beam, a linear module is arranged at the bottom of the gantry cross beam, and the main shaft is fixedly connected to the linear module.

3. A friction stir welding weld structure control device as claimed in claim 1, characterized in that: The workbench is slidably connected to the base, and an extrusion clamp is fixed on the upper surface of the workbench.

4. A friction stir welding weld structure control device as claimed in claim 1, characterized in that: The laser vibrometer is arranged below the spindle support and on one side of the welding direction. It moves synchronously with the spindle to collect vibration frequency data generated by the stirring head on the workpiece.

5. The device for controlling the weld structure of friction stir welding according to claim 1, characterized in that: The infrared thermometer is arranged below the main shaft support on the side opposite to the welding direction, and moves synchronously with the main shaft to collect the temperature data of the weld.

6. The device for controlling the weld structure of friction stir welding according to claim 1, characterized in that: One end of the ultrasonic exciter is connected to an ultrasonic generator to convert high-frequency electrical signals into mechanical vibrations to control the amplitude and frequency.

7. The device for controlling the weld structure of friction stir welding according to claim 1, characterized in that: The control system also includes a signal auxiliary processing computer, and the ultrasonic generator and the water cooler are both electrically connected to the signal auxiliary processing computer.

8. A friction stir welding weld structure control device as claimed in claim 7, characterized in that: The infrared thermometer and the laser vibrometer are both connected to the signal auxiliary processing computer via a data transmission module.

9. A method for controlling the structure of a friction stir welding weld, using a device for controlling the structure of a friction stir welding weld as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Start the ultrasonic generator, water cooler, laser vibrometer and infrared thermometer, adjust the irradiation angle of the infrared thermometer and laser vibrometer, aim the infrared thermometer at the weld area, and aim the laser vibrometer at the weld surface area; According to the geometric shapes of the workpiece and the stirring head and the welding requirements, a numerical control program is compiled in the signal-assisted processing computer, and the welding process parameters, temperature field peak value and ultrasonic vibration parameter range are input into the numerical control program; During the welding process of the stirring head moving, the real-time temperature data of the weld collected by the infrared thermometer is sent to the signal auxiliary processing computer through the data transmission module. The signal auxiliary processing computer displays the real-time temperature data and compares the real-time temperature data with the peak value of the temperature field. If the real-time temperature data is higher than the peak value of the temperature field, the coolant flow rate in the cooling cavity is increased; if the real-time temperature data is less than or equal to the peak value of the temperature field, the coolant flow rate in the cooling cavity is reduced, and finally the weld temperature is kept stable; The real-time amplitude and frequency data of the weld collected by the laser vibrometer is sent to the signal auxiliary processing computer through the data transmission module. The signal auxiliary processing computer displays the real-time amplitude and frequency data and compares the real-time amplitude and frequency data with the expected amplitude and frequency value. If the real-time amplitude and frequency data is higher than the expected amplitude and frequency value, the ultrasonic generator is controlled to reduce the amplitude and frequency; if the real-time amplitude and frequency data is lower than the expected amplitude and frequency value, the ultrasonic generator is controlled to increase the amplitude and frequency, so as to finally keep the amplitude and frequency of the weld stable.

10. A friction stir welding weld microstructure control method as claimed in claim 9, characterized in that: The welding seam temperature and the amplitude frequency are adjusted synchronously.

Images