CN114406439A - Claw-shaped rivet suitable for friction stir rivet welding and friction stir rivet welding method - Google Patents

Abstract

A claw-shaped rivet suitable for friction stir rivet welding and a friction stir rivet welding method are provided, wherein the claw-shaped rivet comprises a clamping section and a riveting section, and the riveting section is composed of a plurality of nail legs which are uniformly distributed in the circumferential direction; the upper surface of the clamping section is provided with a clamping groove and a positioning groove, and the lower surface of the clamping section is provided with a circular groove; the end surface of the shaft shoulder of the clamping section is an inwards concave conical surface and is provided with an annular flow guide groove; the outer/inner peripheral side wall surfaces of the nail legs are arc cylindrical surfaces, the centers of the circles of the arc cylindrical surfaces are overlapped, and the thickness of the nail legs is 1-3 mm; the screw thread convex ribs are arranged on the side wall surfaces of the peripheries of the nail legs; two side vertical surfaces for connecting the inner and outer side wall surfaces of the nail leg are set as flow guide surfaces, the included angle between the flow guide surface and the wall surface is 30-160 degrees, and the two flow guide surfaces are respectively a forward inclined plane and a backward inclined curved surface; the side end face of the nail leg shaft is an inclined plane and is provided with a cutting lug. The method comprises the following steps: initially rotating and binding and applying ultrasonic vibration; stopping rolling and regulating the temperature through rivet rotation; secondary rotation is carried out, and the rivet is downwards rolled to an interface or a set position; press down quickly and form a mechanical interlock at the interface.

Description

Claw rivet suitable for friction stir riveting and friction stir riveting method

technical field

The invention belongs to the technical field of friction stir riveting, in particular to a claw rivet suitable for friction stir riveting and a friction stir riveting method.

Background technique

With the acceleration of scientific and technological research and development, the development of manufacturing and the diversification of industrial demands, the same metal structure can no longer meet the needs of industrial use due to its single performance, while the dissimilar metal structure can be scientifically carried out according to the physical and chemical properties and mechanical properties of each material combined with service requirements. Reasonable collocation, so it is widely used in electric power industry, automobile manufacturing, ships and ships, aerospace and other fields. Since the application of dissimilar metal structures is often determined by the quality of the connection, the realization of high-strength effective connections has extensive and far-reaching significance in scientific research and engineering applications.

Due to the large differences in physical properties, chemical compositions and mechanical properties of dissimilar metals that are difficult to connect, and chemical reactions may occur between different materials, the connection of dissimilar metals is much more complicated than that of the same metal. many questions.

For example: 1. When welding aluminum-steel, since the solid solubility between aluminum-steel is extremely low, it is easy to form brittle and hard intermetallic compounds, and the difference in thermal expansion coefficient and thermal conductivity between the two is large, which will cause a large difference after welding. The residual stress causes cracks to initiate and expand in the intermetallic compound layer, resulting in a decrease in joint strength.

2. When welding aluminum and copper, due to the large difference in thermophysical properties of aluminum and copper, a variety of brittle, hard, insoluble intermetallic compounds will be formed at the interface, resulting in defects such as pores, cracks, and oxidation after welding.

3. When welding titanium steel, due to the large difference in melting point and thermal conductivity of titanium steel, a great residual stress will be formed after welding, which will lead to cracks in the weld, and brittle intermetallics are prone to occur between titanium steels. compounds, which further reduces the plasticity and high temperature properties of the joint.

Therefore, at present, the welding of dissimilar metals generally has problems such as low tensile strength, poor weld formation, low stability, and difficulty in regulating the intermetallic compound layer at the interface. However, mechanical riveted joints still have problems such as short fatigue life, poor sealing performance, and easy corrosion. Due to the need to prefabricate through holes on the plate during mechanical riveting, the hole-making process not only increases the complexity of the process, but also the excess products such as burrs generated during the hole-making process will also affect the service performance, resulting in a significant increase in the cost of the mechanical riveting process.

Since the mechanical riveting process that requires prefabricated through holes has been unable to meet the requirements of high-strength dissimilar metal connections, the self-piercing riveting technology came into being. There are limitations in applicability. When riveting a metal with high hardness, it is necessary to quickly punch the semi-hollow rivet to lower the plate to be connected, which leads to the phenomenon of upsetting and fracture of the rivet, so that an effective mechanical interlock cannot be formed. When riveting a metal with low toughness and high brittleness, it is easy to cause cracks and cracks in the plates to be connected, thereby reducing the strength and fatigue performance of the joint.

Therefore, in view of the limitations of the self-piercing riveting process, the Friction Self-piercing Riveting (F-SPR for short) is proposed. When inserted into the plate to be connected, the rivet and the upper and lower plates form mechanical self-locking, and the rivet realizes solid-phase connection with the metal to be riveted under the action of friction heat.

For example, the Chinese patent application with the application number of 201610566456.3 discloses a rivet for self-piercing friction riveting and its self-piercing friction riveting connection system. Although it can improve the stability and riveting accuracy of the rivet when it rotates at high speed, but The annular hollow rivet used is not easily deformed in the upsetting stage, resulting in insufficient opening of the nail legs, resulting in a small amount of mechanical interlocking, and the heat generated by the rivet rotating friction is not enough to soften the metal with low ductility, so it cannot inhibit the cracking of the plate. Moreover, the solid-phase connection between the rivet and the metal to be riveted cannot be achieved, which will eventually reduce the mechanical-solid-phase dual connection strength.

The Chinese patent application with the application number of 201911256371.5 discloses a friction stir spot welding and riveting tool and method for removing the hook-shaped defects of aluminum-steel lap joints. By adding a raised platform in the middle and lower part of the conventional stirring head, the bottom of the platform is The friction of the aluminum-steel lap plane provides heat to break the lap interface, so as to realize the connection method of welding and riveting. However, the stirring needle at the bottom of the raised platform is easy to break as a whole when the knife is lifted, and the great pulling force when the knife is lifted can easily cause damage to the joint, thereby reducing the connection strength of the joint.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the present invention provides a claw rivet suitable for friction stir riveting and a friction stir riveting method. The newly designed claw rivet can effectively reduce the difficulty of deformation of the rivet and improve the mechanical properties of the rivet. Self-locking strength can guide the flow of plastic metal to improve the sealing performance of riveted joints; through the combination of rivets and process methods, the heat input in the riveting process can be reasonably controlled, the problem of insufficient heat generation of rivets can be solved, and the relationship between dissimilar metal plates, rivets and plates can be promoted. The metallurgical connection between the two can improve the ductility of the plate, it is easy to tie down the rivet, and the cracking of the plate can be avoided; through the ultrasonic vibration, the intermetallic compound generated by the dissimilar metals under the action of heat can be effectively controlled, and the connection performance of the dissimilar metals that are difficult to connect can be improved.

In order to achieve the above purpose, the present invention adopts the following technical scheme: a claw rivet suitable for friction stir riveting, comprising a clamping section and a riveting section, the clamping section adopts a disc-shaped structure, and the disc of the clamping section is The upper surface is the clamping and positioning side, and the lower surface of the disc of the clamping section is the shoulder side; the riveting section is located on the shoulder side of the clamping section, and the riveting section is composed of a plurality of nail legs, and the plurality of nail legs are along the circumferential direction. Evenly distributed, and the number of nail legs is 2 to 6.

A plurality of clamping grooves are evenly distributed on the upper surface of the disc of the clamping section along the circumferential direction, and a positioning groove is arranged at the center of the upper surface of the disc of the clamping section. A circular groove is provided at the center of the surface.

The end face of the disc shaft shoulder of the clamping segment on the outer side of the nail leg is a concave conical surface, and an annular flow guiding groove is provided on the end face of the clamping segment disc shaft shoulder at the outer side of the nail leg.

The outer peripheral side wall surface and the inner peripheral side wall surface of the nail legs are arc cylindrical surfaces, and the center of the outer peripheral side wall surface and the inner peripheral inner wall surface of all nail legs coincide; the thickness of the nail legs in the radial direction is 1mm ~3mm.

The thread protruding ribs are arranged on the outer peripheral side walls of the nail legs, and the thread protruding ribs on the outer peripheral side walls of all the nail legs are mutually thread extensions.

The two side elevations used to connect the outer peripheral side wall surface and the inner peripheral side wall surface of the nail legs are respectively set as the first flow guiding surface and the second guiding surface, and the first guiding surface is connected with the outer peripheral side wall surface and the inner peripheral surface of the nail leg. The included angle of the side wall surface is 30°～160°, the included angle between the second guide surface and the outer peripheral side wall surface and the inner peripheral side wall surface of the nail leg is 30°～160°; the first guide surface is flat and inclined forward , the second guide surface is a curved surface and is inclined backward.

The axial end surface of the nail leg is an inclined plane, and a cutting bump is provided on the axial end surface of the nail leg at the intersection of the first flow guide surface and the outer peripheral side wall surface.

A friction stir riveting method, which adopts the claw rivet suitable for friction stir riveting, comprises the following steps:

Step 1: Initial spin down stage

Control the pressing ring of the friction stir welding machine to press down until the pressing ring is in close contact with the surface of the upper layer of the material to be welded, and then control the chuck of the friction stir welding machine to rotate and drive the claw rivets to tie down, and the claw rivets are tied down. During the process, ultrasonic vibration is applied through the chuck or pressing ring of the friction stir welding machine;

Step 2: Temperature Control Stage

When the lowering depth of the claw rivet on the upper layer of the material to be welded reaches the set value, the claw rivet that controls the rotation stops being pulled down, and then the rotation speed of the claw rivet is adjusted, and the dissimilar metal material is regulated by changing the rotation of the claw rivet. The temperature distribution at the interface of the joint enables the interface of dissimilar metal materials and claw rivets to obtain a uniform temperature distribution that meets the requirements of solid-state welding;

Step 3: The second rotation and lower tie stage

Control the rotation of the claw rivets to continue lowering until the lowering depth of the claw rivets reaches the set position at the interface of the dissimilar material joint or in the lower layer of the material to be welded;

Step 4: Rapid Depression Stage

Control the claw rivet to stop rotating and press down quickly, so that the heated and softened claw rivet legs are squeezed and deformed and opened under the obstruction of the lower material to be welded, thereby forming a mechanical interlock at the joint interface of dissimilar metal materials.

In the pre-welding preparation stage before step 1, alcohol or acetone is used to remove the oil on the surface of the dissimilar metal material to be welded, and then the upper and lower layers of the material to be welded are lapped together with a clamp for fixing, and then the claw rivet is passed through the The clamping section is assembled with the collet of the friction stir welding machine, and finally the collet equipped with the claw rivet is moved above the riveting welding position of the material to be welded.

In the pre-welding preparation stage before step 1, the parameters of friction stir riveting in steps 1 to 4 need to be set, including the rotation speed, pressing speed, pressing amount and dwell time of the claw rivet.

Beneficial effects of the present invention:

1. Compared with the traditional mechanical riveting, the present invention eliminates the tedious process of prefabricating holes, reduces the process cost, and the heat input in the riveting process is small and controllable. Changes in acoustic flow and cavitation effects can change the dynamic environment of the interface, effectively inhibiting the growth of intermetallic compounds at the interface. Macroscopically, the thickness of the intermetallic compound layer is reduced, and mechanical interlocking can be formed between claw rivets and dissimilar materials. Combined with metallurgy, it greatly improves the bonding strength of difficult-to-connect dissimilar metals.

2. The present invention can effectively increase the effective stirring area of the rivet through the newly designed claw rivet, increase the plastic metal flow degree in the stirring area, improve the heat production efficiency, and can obtain the required temperature for riveting in a short time, reducing the time The processing time can reduce the generation of brittle intermetallic compounds, and at the same time, a large amount of heat will ensure that the dissimilar metal interface that is not stirred in the inner cylindrical space of the nail leg achieves metallurgical bonding, which further improves the mechanical properties of the riveted joint.

3. In the present invention, the thickness of the nail legs of the claw-type rivet is set at 1 mm to 3 mm. After the rivet rotates and friction generates heat, the nail legs are softened by heat and are more likely to deform and open, so as to form an excellent mechanical interlock, thereby improving the performance of the rivet. mechanical interlock strength.

4. The claw rivet of the present invention adopts the nail legs with a fluid-type curved surface design. During the rotation and pressing of the claw rivet, the two guide surfaces of the nail legs can promote the flow of metal materials to the inner cylindrical space area of the nail legs. And fill the cylindrical space area, the overflowing metal material flows out from the root of the nail leg and fills the annular diversion groove on the end face of the shoulder of the clamping section on the outer side of the nail leg to form a sealed connection, thereby improving the corrosion resistance of the joint. Reduce chip evacuation and reduce follow-up processing costs, while the threaded ribs on the outer peripheral sidewall of the nail legs can also speed up longitudinal metal flow.

Description of drawings

1 is a schematic structural diagram of a claw rivet suitable for friction stir riveting according to the present invention (perspective 1);

2 is a schematic structural diagram of a claw rivet suitable for friction stir riveting according to the present invention (perspective 2);

3 is a schematic structural diagram of a claw rivet suitable for friction stir riveting according to the present invention (viewing angle three);

4 is a schematic structural diagram of a claw rivet suitable for friction stir riveting according to the present invention (view four);

5 is a schematic diagram of the implementation process of the friction stir riveting method of the present invention;

In the figure, 1—Nail leg, 2—Clamping groove, 3—Locating groove, 4—Circular groove, 5—Annular diversion groove, 6—Outer peripheral side wall surface, 7—Inner peripheral sidewall surface, 8 - Threaded rib, 9 - first guide surface, 10 - second guide surface, 11 - cutting bump, 12 - pressing ring, 13 - claw rivet.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figures 1 to 4, a claw rivet suitable for friction stir riveting includes a clamping section and a riveting section, the clamping section adopts a disc-shaped structure, and the upper surface of the disc of the clamping section is On the clamping positioning side, the lower surface of the disc of the clamping section is the shoulder side; the riveting section is located on the shoulder side of the clamping section, and the riveting section is composed of a plurality of nail legs 1, and the plurality of nail legs 1 are evenly distributed along the circumferential direction set, and the number of nail legs 1 is 2 to 6.

A plurality of clamping grooves 2 are evenly distributed on the upper surface of the disc of the clamping segment along the circumferential direction, and a positioning groove 3 is provided at the center of the upper surface of the disc of the clamping segment. A circular groove 4 is provided at the center of the lower surface of the disc.

The end face of the disc shaft shoulder of the clamping segment outside the nail leg 1 is a concave conical surface, and an annular guide groove 5 is provided on the end face of the clamping segment disc shaft shoulder outside the nail leg 1 .

The outer peripheral side wall surface 6 and the inner peripheral side wall surface 7 of the nail legs 1 are arc cylindrical surfaces, and the centers of the outer peripheral side wall surfaces 6 and the inner peripheral inner wall surface 7 of all nail legs 1 coincide; The thickness in the direction is 1 mm to 3 mm.

A thread protruding rib 8 is provided on the outer peripheral side wall surface 6 of the nail leg 1 , and the thread protruding ribs 8 on the outer peripheral side wall surface 6 of all the nail legs 1 are mutually thread extensions.

The two side elevations used to connect the outer peripheral side wall surface 6 and the inner peripheral side wall surface 7 of the nail leg 1 are respectively set as the first guide surface 9 and the second guide surface 10, and the first guide surface 9 and the nail leg are respectively set. 1. The angle between the outer peripheral side wall surface 6 and the inner peripheral side wall surface 7 is 30°～160°, and the included angle between the second guide surface 10 and the outer peripheral side wall surface 6 and the inner peripheral side wall surface 7 of the nail leg 1 is 30°～160° ; The first guide surface 9 is flat and inclined forward, and the second guide surface 10 is curved and inclined backward.

The axial end surface of the nail leg 1 is an inclined plane, and a cutting bump 11 is provided on the axial end surface of the nail leg 1 where the first guide surface 9 meets the outer peripheral side wall surface 5 .

In this embodiment, the number of nail legs 1 is 3, the thickness of nail legs 1 in the radial direction is 2 mm, the forward inclination angle of the first guide surface 9 is 2° to 20°, and the second guide surface 10 The angle of back inclination is 2°～20°, the angle between the first guide surface 9 and the outer peripheral side wall surface 6 of the nail leg 1 is 30°～40°, the first guide surface 9 and the inner peripheral side wall surface 7 of the nail leg 1 The included angle is 130°～160°, the included angle between the second guide surface 10 and the outer peripheral side wall surface 6 of the nail leg 1 is 40°～60°, and the included angle between the second guide surface 10 and the inner peripheral side wall surface 7 is 100°～130°, the inclination angle of the end face of the shaft side of the nail leg 1 is 10°～30°, the taper angle of the end face of the disc shaft shoulder of the clamping segment outside the nail leg 1 is 175°～180°, and the threaded convex rib is 8 Right-hand thread.

In this embodiment, the material to be welded on the upper layer is a 6061-T6 aluminum alloy plate, the material to be welded on the lower layer is a DP590 steel plate, the thickness of the 6061-T6 aluminum alloy plate is 3 mm, and the thickness of the DP590 steel plate is 2 mm. The direction is counterclockwise.

A method for friction stir riveting, as shown in Figure 5, adopts the claw rivet suitable for friction stir riveting, including the following steps:

Step 1: Initial spin down stage

Control the pressing ring 12 of the friction stir welding machine to press down until the pressing ring 12 is in close contact with the surface of the upper layer of the material to be welded, then control the chuck of the friction stir welding machine to rotate and drive the claw rivet 13 to tie down, and the claw rivet 13 Ultrasonic vibration is applied through the chuck of the friction stir welding machine or the pressing ring 12 during the lowering process; among them, in the pre-welding preparation stage, alcohol or acetone is used to remove the oil on the surface of the dissimilar metal material to be welded, and then the fixture is used to The upper and lower layers of the material to be welded are lapped together for fixing, and then the claw rivet 13 is assembled with the chuck of the friction stir welding machine through its clamping section, and finally the chuck equipped with the claw rivet 13 is moved to the waiting position. Above the riveting position of the welding material; in addition, it is necessary to complete the setting of friction stir riveting parameters before welding, including the rotation speed of the claw rivet 13 in each stage, the pressing speed, the pressing amount and the dwell time;

Step 2: Temperature Control Stage

When the lowering depth of the claw rivet 13 in the upper layer of the material to be welded reaches the set value, the claw rivet 13 is controlled to be rotated to stop lowering, and then the rotation speed of the claw rivet 13 is adjusted. Regulate the temperature distribution at the interface of dissimilar metal material joints, so that the interface between dissimilar metal materials and claw rivet 13 can obtain a uniform temperature distribution that meets the requirements of solid-state welding;

Step 3: The second rotation and lower tie stage

The claw-shaped rivet 13 controlled to rotate continues to lower until the lowering depth of the claw-shaped rivet 13 reaches the set position at the interface of the dissimilar material joint or in the lower layer of the material to be welded;

Step 4: Rapid Depression Stage

Control the claw rivet 13 to stop rotating and press down rapidly, so that the nail legs 1 of the claw rivet 13 softened by heat are squeezed and deformed and open under the obstruction of the lower layer of the material to be welded, thereby forming a mechanical interaction at the joint interface of dissimilar metal materials. Lock. After that, the connection between the friction stir welding machine chuck and the claw rivet 13 can be disconnected, and at the same time, the pressing ring 12 is controlled to move up and release the pressing of the upper layer of the material to be welded, and the friction stir riveting process ends.

After the above-mentioned friction stir riveting process, the connection strength of the aluminum-steel dissimilar metal plates can be greatly improved. During the friction stir riveting process, when the cutting bumps 11 on the axial end surface of the nail legs 1 of the claw rivets 13 are in contact with the upper aluminum alloy plate, the cutting bumps 11 are pressed down as the claw rivets 13 rotate. Under the action, the upper aluminum alloy plate is cut, so that the nail legs 1 of the claw rivets 13 are more easily inserted into the upper aluminum alloy plate. With the continuous rotation and pressing of the claw rivet 13 , the aluminum alloy material entering from the first guide surface 9 will hardly flow out from the lower end of the second guide surface 10 , and the aluminum alloy material will be in the columnar shape inside the three nail legs 1 . Space gathering. When the claw rivet 13 is inserted into the lower steel plate, the aluminum alloy material will fill the cylindrical space inside the three nail legs 1, and then will be discharged from the upper end of the second guide surface 10, and further enter the annular guide groove 5 to form a sealed connection. Through the design of the multiple nail legs 1, the heat generation efficiency of the claw rivet 13 is effectively improved, the processing time is reduced, and the heat required for forming a metallurgical bond between dissimilar plates, plates and rivets is provided. In addition, ultrasonic vibration is applied through the chuck of the friction stir welding machine or the pressing ring 12 during the lowering of the claw rivet 13, which can effectively inhibit the adhesion and growth of intermetallic compounds at the interface and ensure the strength of the joint. In the rapid pressing stage, the legs 1 of the thinner claw rivets 13 are softened by heat and are more likely to be deformed and opened, so as to form an excellent mechanical interlock. In the continuous friction stir riveting, the fast and convenient clamping by the claw rivets 13 greatly improves the production efficiency.

The solutions in the embodiments are not intended to limit the scope of the patent protection of the present invention, and all equivalent implementations or modifications that do not depart from the present invention are included in the scope of the patent of this case.

Claims (10)

1. a claw-type rivet suitable for friction stir riveting, characterized in that: comprising a clamping section and a riveting section, the clamping section adopts a disc-shaped structure, and the upper surface of the disc of the clamping section is a clamping and positioning The lower surface of the disc of the clamping section is the shoulder side; the riveting section is located on the shoulder side of the clamping section, the riveting section is composed of a plurality of nail legs, and the plurality of nail legs are evenly distributed along the circumferential direction, and the nails The number of legs is 2 to 6. 2. The claw-type rivet suitable for friction stir riveting according to claim 1, characterized in that: a plurality of clamping grooves are evenly distributed along the circumferential direction on the upper surface of the disc of the clamping section , a positioning groove is arranged at the center of the upper surface of the disc of the clamping segment, and a circular groove is arranged at the center of the lower surface of the disc of the clamping segment. 3. A claw rivet suitable for friction stir riveting according to claim 1, characterized in that: the shoulder end face of the clamping segment disc on the outer side of the nail leg is a concave conical surface, and the end face of the disc shaft shoulder on the outer side of the nail leg An annular flow guiding groove is arranged on the end face of the shoulder of the disc of the outer clamping segment. 4. A claw-type rivet suitable for friction stir riveting according to claim 1, wherein the outer peripheral side wall surface and the inner peripheral side wall surface of the nail legs are arc cylindrical surfaces, and all the nail legs The centers of the outer peripheral side wall surface and the inner peripheral inner wall surface coincide; the thickness of the nail legs in the radial direction is 1 mm to 3 mm. 5. A claw rivet suitable for friction stir riveting according to claim 4, characterized in that: threaded ribs are provided on the outer peripheral sidewall surfaces of the nail legs, and all the outer peripheral sidewall surfaces of the nail legs The thread protruding ribs of each other are extensions of each other's threads. 6. A claw rivet suitable for friction stir riveting according to claim 4, characterized in that: the two side elevations used to connect the outer peripheral side wall surface and the inner peripheral side wall surface of the nail legs are respectively set as The first guide surface and the second guide surface, the angle between the first guide surface and the outer peripheral side wall surface and the inner peripheral side wall surface of the nail leg is 30° to 160°, and the second guide surface and the outer peripheral side wall surface of the nail leg are 30° to 160°. The included angle of the inner peripheral side wall surface is 30°˜160°; the first flow guide surface is flat and inclined forward, and the second flow guide surface is curved and inclined backward. 7. A claw rivet suitable for friction stir riveting according to claim 6, characterized in that: the axial end surface of the nail leg is an inclined plane, and the first guide surface and the outer peripheral side Cutting bumps are arranged on the shaft-side end surfaces of the nail legs where the walls meet. 8. a friction stir riveting method, adopting the claw type rivet suitable for friction stir riveting according to claim 1, it is characterized in that comprising the steps: Step 1: Initial spin down stage Control the pressing ring of the friction stir welding machine to press down until the pressing ring is in close contact with the surface of the upper layer of the material to be welded, and then control the chuck of the friction stir welding machine to rotate and drive the claw rivets to tie down, and the claw rivets are tied down. During the process, ultrasonic vibration is applied through the chuck or pressing ring of the friction stir welding machine; Step 2: Temperature Control Stage When the lowering depth of the claw rivet on the upper layer of the material to be welded reaches the set value, the claw rivet that controls the rotation stops being pulled down, and then the rotation speed of the claw rivet is adjusted, and the dissimilar metal material is regulated by changing the rotation of the claw rivet. The temperature distribution at the interface of the joint enables the interface of dissimilar metal materials and claw rivets to obtain a uniform temperature distribution that meets the requirements of solid-state welding; Step 3: The second rotation and lower tie stage Control the rotation of the claw rivets to continue lowering until the lowering depth of the claw rivets reaches the set position at the interface of the dissimilar material joint or in the lower layer of the material to be welded; Step 4: Rapid Depression Stage Control the claw rivet to stop rotating and press down quickly, so that the heated and softened claw rivet legs are squeezed and deformed and opened under the obstruction of the lower material to be welded, thereby forming a mechanical interlock at the joint interface of dissimilar metal materials. 9. A kind of friction stir riveting welding method according to claim 8, it is characterized in that: in the pre-welding preparation stage before performing step 1, first use alcohol or acetone to remove the oil stain on the surface to be welded of dissimilar metal materials, and then use a fixture The upper and lower layers of the materials to be welded are lapped together for fixing, and then the claw rivet is assembled with the chuck of the friction stir welding machine through its clamping section, and finally the chuck equipped with the claw rivet is moved to the place to be welded. Above the riveting position of the material. 10 . The method for friction stir riveting according to claim 8 , wherein in the pre-welding preparation stage before performing step 1, the parameters of friction stir riveting in steps 1 to 4 need to be set, including: 10 . Rotation speed, pressing speed, pressing amount and dwell time of claw rivets.

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