A friction stir welding apparatus, a friction stir welding method, and a workpiece.

Abstract

This application belongs to the field of friction stir welding technology, and specifically relates to a friction stir welding apparatus, a friction stir welding method, and a workpiece. The friction stir welding apparatus includes a stirring head and a follower pressure ring. The stirring head includes a shoulder and a stirring pin connected to the first end of the shoulder. The follower pressure ring has an inner hole, and the stirring head is movably inserted into the inner hole. The end face of the first end of the shoulder is flush with the lower end face of the follower pressure ring. The follower pressure ring forms a cavity with the shoulder on one side in the welding forward direction, and the lower end face of the other side is a plane. The above structure not only enables friction stir welding through the stirring head, but also allows the lower end face of the follower pressure ring to press down on the welded area, thereby restraining and eliminating flash.

Description

Technical Field

[0001] This application belongs to the field of friction stir welding technology, and specifically relates to a friction stir welding apparatus, a friction stir welding method, and a workpiece. Background Technology

[0002] Friction stir welding utilizes frictional heat and thermoplastic deformation heat as the welding heat source. The welding process involves inserting a stirring pin into the weld seam of the workpiece. The high-speed rotation of the stirring head causes friction between the pin and the workpiece material, raising the temperature and softening the material at the joint. Simultaneously, the material is stirred and frictionally stirred to complete the weld. Friction stir welding offers advantages such as the ability to complete long welds in a single operation, ease of mechanization and automation, simple equipment, no need for welding wire, and a safe and pollution-free welding process.

[0003] In traditional friction stir welding, the stirring pin is inserted into the workpiece to be welded, and the stirring shoulder applies a certain amount of pressure to the surface of the workpiece to fully compress and backfill the thermoplastic material on the surface of the workpiece under the shoulder, thereby ensuring weld formation. During the welding process, frictional heat is generated between the rotation of the stirring tool and the workpiece. Excessive frictional heat can cause deformation and internal stress in the workpiece. Moreover, the downward pressure of the shoulder on the surface of the workpiece during welding will inevitably result in flash. Summary of the Invention

[0004] The purpose of this invention is to provide a friction stir welding apparatus, a friction stir welding method, and a workpiece to solve the problem of flash formation in friction stir welding in the prior art.

[0005] The first aspect of the present invention provides a friction stir welding apparatus, comprising:

[0006] A stirring head, the stirring head including a shoulder and a stirring needle connected to a first end of the shoulder;

[0007] The moving pressure ring has an inner hole, the stirring head is movably inserted into the inner hole, and the end face of the first end of the shoulder is flush with the lower end face of the moving pressure ring; the moving pressure ring forms a cavity with the shoulder on one side in the welding forward direction, and the lower end face on the other side is a plane.

[0008] The friction stir welding apparatus provided by this invention may also have the following additional technical features:

[0009] In one specific embodiment of the present invention, the lower end of the follower pressure ring is further provided with an ultrasonic vibrator.

[0010] In one specific embodiment of the present invention, the ultrasonic vibrator is disposed on the side of the follower pressure ring away from the welding forward direction.

[0011] In one specific embodiment of the present invention, the lower end of the follower pressure ring is provided with a water inlet on one side of the welding advance direction, and the water inlet is connected to an external water mist cooling device.

[0012] In one specific embodiment of the present invention, a thermal management mechanism is also integrated within the follower pressure ring.

[0013] In one specific embodiment of the present invention, the thermal management mechanism includes a water-cooled structure, a cooling medium, and / or a heat pipe.

[0014] A second aspect of the present invention also provides a friction stir welding method, implemented using the friction stir welding apparatus described in any one of the preceding claims, comprising:

[0015] Two workpieces with a thickness h≥1mm are fixed side by side on a fixture to form a weld.

[0016] The stirring head, which is fitted with the pressure ring, is driven to rotate at the starting position to penetrate the weld of the workpiece until a preset depth is reached and then penetration stops.

[0017] The rotating stirring head advances along the weld seam to perform friction stirring welding of the workpiece, while the follower pressure ring rolls the weld surface and removes burrs.

[0018] In one specific embodiment of the present invention, before driving the stirring head, on which the pressure ring is sleeved, to rotate at the weld initiation position to penetrate the weld seam of the workpiece, the method further includes:

[0019] Adjust the installation position of the stirring head and the follower pressure ring so that their center lines form an angle of 0.5°-10° with the center line of the equipment head.

[0020] In one specific embodiment of the present invention, the material of the workpiece is aluminum and aluminum alloys, magnesium alloys, copper and copper alloys, or titanium alloys.

[0021] A third aspect of the present invention also provides a workpiece, which is welded using the friction stir welding apparatus described in any one of the preceding claims.

[0022] The friction stir welding device provided by the present invention has a relatively stationary follower pressure ring set on the outside of the stirring head. Firstly, it can act as a cold source to remove some of the heat generated during welding and reduce welding deformation. Secondly, it can also act as a guide roller to flatten the area to be welded to ensure the quality of the weld. Thirdly, the lower end face of the follower pressure ring can press down on the area after welding, thereby restraining and eliminating burrs. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a friction stir welding device in a specific embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the weld after welding in a specific implementation embodiment;

[0026] Figure 3 This is a schematic diagram of the weld after welding in another specific embodiment.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10-Stirring head, 11-Stirring needle, 12-Shoulder; 20-Follow-up pressure ring, 21-Ultrasonic vibrator, 22-Thermal management mechanism, 23-Water inlet; 30-Workpiece. Detailed Implementation

[0029] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0030] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0031] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0032] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0033] like Figure 1 As shown, the first aspect of the present invention provides a friction stir welding apparatus, comprising:

[0034] A stirring head 10, the stirring head 10 including a shoulder 12 and a stirring needle 11 connected to a first end of the shoulder 12;

[0035] The moving pressure ring 20 has an inner hole, the stirring head 10 is movably inserted into the inner hole, and the end face of the first end of the shoulder 12 is flush with the lower end face of the moving pressure ring 20; the moving pressure ring 20 forms a cavity with the shoulder 12 on one side in the welding forward direction, and the lower end face on the other side is a plane.

[0036] In the above structure, the stirring head 10 is mounted on the machine head and can rotate and move under the drive of the machine head to penetrate the workpiece 30 through the stirring needle 11 and perform friction stir welding. The follower pressure ring 20 has an inner hole and is sleeved on the outside of the stirring head 10 through the inner hole, with its lower end face flush with the end face of the first end of the shoulder 12. The stirring head 10, inserted into the inner hole, can rotate freely within the follower pressure ring 20. The inner hole is in the welding forward direction (…). Figure 1 The middle arrow (in the direction of welding) extends from the side away from the shoulder 12 to form a cavity with the shoulder 12. During welding, excess material can be discharged through the cavity. The other end face of the follower pressure ring 20 is flat, which can roll the weld surface to remove burrs. The follower pressure ring 20 can also act as a cold source to remove some of the heat generated during welding, reducing welding deformation. The follower pressure ring 20 can also act as a guide roller to flatten the area to be welded to ensure weld quality.

[0037] like Figure 1 As shown, in one specific embodiment of the present invention, an ultrasonic vibrator 21 is further provided at the lower end of the follower pressure ring 20. Specifically, the ultrasonic vibrator 21 is located on the side of the follower pressure ring 20 opposite to the welding forward direction. During the welding process, the ultrasonic vibrator 21 can perform ultrasonic vibration to relieve stress on the weld that has already been welded, reduce residual stress in the weld, reduce deformation of the parts, and improve weld performance.

[0038] like Figure 1 As shown, in one specific embodiment of the present invention, the lower end of the follower pressure ring 20 is further provided with a water inlet 23 on one side of the welding advance direction, and the water inlet 23 is connected to an external water mist cooling device. During the welding process, water mist can be applied to the welding position through the water mist cooling device to cool the weld.

[0039] like Figure 1 As shown, in one specific embodiment of the present invention, a thermal management mechanism 22 is also integrated within the follower pressure ring 20. Specifically, the thermal management mechanism 22 includes a water-cooling structure, a cooling medium, and / or a heat pipe. The thermal management mechanism 22 can effectively manage the heat during the welding process, dissipate excess heat in a timely manner, reduce the heat input of the weld, weaken grain growth, reduce residual thermal stress, and improve the overall performance of the weld.

[0040] A second aspect of the present invention also provides a friction stir welding method, implemented using the friction stir welding apparatus described in any one of the preceding claims, comprising:

[0041] Two workpieces 30 with a thickness h≥1mm are fixed side by side on a fixture to form a weld.

[0042] The stirring head 10, which is fitted with the pressure ring, is driven to rotate at the starting position to penetrate the weld of the workpiece 30 until a preset depth is reached and then penetration stops.

[0043] The rotating stirring head 10 advances along the weld seam to perform friction stirring welding of the workpiece 30, while the follower pressure ring 20 rolls the weld surface and removes burrs.

[0044] Specifically, the rotation speed of the stirring head 10 can be set to 500–2500 rpm. It then penetrates the workpiece 30 to be welded. Once the stirring shoulder 12 reaches the preset position, penetration stops, with a penetration depth typically between 0.1 and 0.3 mm. The stirring head 10 is then driven forward at a speed of 50–1500 mm / min. Figure 1 The direction of the middle arrow indicates the direction of welding.

[0045] In one specific embodiment of the present invention, before driving the stirring head 10, on which the pressure ring is sleeved, to rotate at the weld initiation position to penetrate the weld seam of the workpiece 30, the following steps are included:

[0046] Adjust the installation positions of the stirring head 10 and the follower pressure ring 20 so that their center lines form an angle of 0.5°-10° with the center line of the equipment head. Figure 1 The value of α in the equation ranges from 0.5° to 10°.

[0047] In one specific embodiment of the present invention, the workpiece 30 is made of aluminum and aluminum alloys, magnesium alloys, copper and copper alloys, or titanium alloys.

[0048] In the above process, the heat during welding can be effectively managed by a heat management mechanism 22 installed inside the follower pressure ring 20, such as water cooling, a cooling medium, or a heat pipe, to dissipate excess heat in a timely manner. This reduces heat input to the weld, weakens grain growth, and reduces residual thermal stress, thereby improving the overall performance of the weld. Simultaneously, since the follower pressure ring 20 is stationary, the portion located behind the stirring shoulder 12 can flatten the welded area and restrain the weld flash. Furthermore, an ultrasonic vibrator 21 integrated at the rear of the follower pressure ring 20 can provide ultrasonic vibration stress relief to the welded area during welding, reducing residual welding stress, minimizing component deformation, and improving weld performance. To further enhance cooling and heat dissipation, a water mist cooling device located at the front of the follower pressure ring 20 can be used to cool the weld during welding.

[0049] Furthermore, the length and diameter of the pressure ring are determined based on the structure of the welded parts to avoid interference. Within a defined range, heat dissipation and internal stress release can also be controlled by changing the size of the follower pressure ring 20 device.

[0050] A third aspect of the present invention also provides a workpiece 30, which is welded using the friction stir welding apparatus described in any one of the above claims.

[0051] Example 1

[0052] 1) Raw material preparation: Take two 6061 aluminum plates with a length, width and height of 500*200*5mm and fix them side by side on the fixture to form a weld.

[0053] 2) Clamping: Clamp the stirring head 10 and the pressure ring onto the machine head of the equipment, and make the welding tilt angle α = 3°;

[0054] 3) Start the stirring head 10: Set the stirring head 10 to a speed of 1200 rpm;

[0055] 4) Friction stir welding: The stirring head 10 and the follower pressure ring 20 move downward to the position where they are embedded in the aluminum plate by 0.2mm, and then move forward at a speed of 800mm / min.

[0056] The weld effect obtained based on the above steps is as follows: Figure 2 As shown. Figure 2 In the middle, the weld seam is flat and without burrs.

[0057] Example 2

[0058] 1) Raw material preparation: Take two 6061 aluminum plates with a length, width and height of 500*200*5mm and fix them side by side on the fixture to form a weld.

[0059] 2) Clamping: Clamp the stirring head 10 and the pressure ring onto the machine head of the equipment, and make the welding tilt angle α = 3°;

[0060] 3) Start the stirring head 10: Set the stirring head 10 to a speed of 1200 rpm;

[0061] 4) Friction stir welding: The stirring head 10 and the follower pressure ring 20 move downward to the position where they are embedded in the aluminum plate by 0.2mm, and then move forward at a speed of 800mm / min.

[0062] The weld effect obtained based on the above steps is as follows: Figure 3 As shown in Figure 3, the weld is smooth and without burrs.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A friction stir welding apparatus, characterized in that, include: A stirring head, the stirring head including a shoulder and a stirring needle connected to a first end of the shoulder; The moving pressure ring has an inner hole, the stirring head is movably inserted into the inner hole, and the end face of the first end of the shoulder is flush with the lower end face of the moving pressure ring; the lower end face of the inner hole of the moving pressure ring extends away from the shoulder on one side in the welding forward direction to form a cavity with the shoulder, and the lower end face on the other side is a plane. The lower end of the follower pressure ring is also provided with an ultrasonic vibrator; The ultrasonic vibrator is located on the side of the follower pressure ring that is away from the welding advance direction.

2. The friction stir welding apparatus according to claim 1, characterized in that, The lower end of the follower pressure ring is also provided with a water inlet on one side of the welding advance direction, and the water inlet is connected to an external water mist cooling device.

3. The friction stir welding apparatus according to claim 1, characterized in that, The follow-up pressure ring also integrates a thermal management mechanism.

4. The friction stir welding apparatus according to claim 3, characterized in that, The thermal management system includes a water-cooled structure, a cooling medium, and / or heat pipes.

5. A friction stir welding method, characterized in that, The friction stir welding apparatus according to any one of claims 1-4 is used, comprising: Two workpieces with a thickness h≥1mm are fixed side by side on a fixture to form a weld. The stirring head, which is fitted with the pressure ring, is driven to rotate at the starting position to penetrate the weld of the workpiece until a preset depth is reached and then penetration stops. The rotating stirring head advances along the weld seam to perform friction stirring welding of the workpiece, while the follower pressure ring rolls the weld surface and removes burrs.

6. The friction stir welding method according to claim 5, characterized in that, Before driving the stirring head, which is fitted with the pressure ring, to rotate at the weld initiation position to penetrate the weld seam of the workpiece, the method further includes: Adjust the installation position of the stirring head and the follower pressure ring so that their center lines form an angle of 0.5°-10° with the center line of the equipment head.

7. The friction stir welding method according to claim 5, characterized in that, The workpiece is made of aluminum and aluminum alloys, magnesium alloys, copper and copper alloys, or titanium alloys.

8. A workpiece, characterized in that, The welding was completed using the friction stir welding apparatus described in any one of claims 1-4.

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