阅读说明：本技术 一种去除搅拌头金属粘料的方法 (Method for removing metal binder of stirring head ) 是由 刘喆 赵运强 林志成 刘莉 苗澍 王春桂 董春林 邓军 于 2021-07-22 设计创作，主要内容包括：本发明涉及摩擦焊的技术领域,公开了一种去除搅拌头金属粘料的方法,包括搅拌头和金属除料板,所述搅拌头的表面粘附有金属粘料,所述搅拌头的熔点高于所述金属除料板和所述金属粘料的熔点,所述搅拌头与所述金属除料板之间的摩擦系数和所述搅拌头与所述金属粘料之间的摩擦系数均小于所述金属除料板与所述金属粘料之间的摩擦系数,将所述搅拌头持续旋转并扎入所述金属除料板,所述金属粘料与所述金属除料板发生软化并混合形成金属混合物,所述搅拌头在所述金属除料板停留3－8秒后,将所述搅拌头抽离所述金属除料板。本发明的去除搅拌头金属粘料的方法,能简单且高效的去除搅拌头金属粘料。(The invention relates to the technical field of friction welding, and discloses a method for removing metal binder of a stirring head, which comprises the stirring head and a metal material removing plate, wherein the surface of the stirring head is adhered with the metal binder, the melting point of the stirring head is higher than the melting points of the metal material removing plate and the metal binder, the friction coefficient between the stirring head and the metal material removing plate and the friction coefficient between the stirring head and the metal binder are both smaller than the friction coefficient between the metal material removing plate and the metal binder, the stirring head is continuously rotated and pricked into the metal material removing plate, the metal binder and the metal material removing plate are softened and mixed to form a metal mixture, and the stirring head is pulled out of the metal material removing plate after the stirring head stays for 3-8 seconds in the metal material removing plate. The method for removing the metal binder of the stirring head can simply and efficiently remove the metal binder of the stirring head.)

1. A method for removing metal binder of a stirring head is characterized by comprising the following steps: the stirring head is continuously rotated and pricked into the metal material removing plate, the metal material and the metal material removing plate are softened and mixed to form a metal mixture, and the stirring head is pulled out from the metal material removing plate after the metal material removing plate stays for 3-8 seconds.

2. The method for removing the metal binder of the stirring head according to claim 1, wherein: the method comprises the following steps:

step 1: the stirring head is rotationally inserted into the metal material removing plate, and the metal binder and the metal material removing plate are softened and generate plastic deformation;

step 2: the metal binder is separated from the stirring head, the metal binder and the metal material removing plate are mixed to form the metal mixture, and the metal mixture is positioned on the periphery of the surface of the stirring head;

and step 3: and drawing out the stirring head from the metal material removing plate.

3. The method for removing the metal binder of the stirring head as recited in claim 2, wherein: in the step 3, a metal mixture layer is formed on the metal material removing plate.

4. The method for removing the metal binder of the stirring head as recited in claim 2, wherein: in the step 2, the adhesive force between the molecules of the metal material removing plate and the molecules of the metal binder is larger than the mechanical engaging force between the metal binder and the stirring head.

5. The method for removing the metal binder of the stirring head according to claim 1, wherein: the stirring head comprises a stirring pin and a stirring head shaft shoulder, the stirring head shaft shoulder is located at the upper end of the stirring pin, a set pressing amount is set when the stirring head penetrates into the metal material removing plate, and the pressing amount is set to be 0.35-0.55 mm.

6. The method for removing the metal binder of the stirring head according to claim 1, wherein: the metal material removing plate is provided with a pre-drilled hole, the diameter of the pre-drilled hole is smaller than the maximum diameter of a stirring pin of the stirring head, and the stirring head penetrates into the pre-drilled hole.

7. The method for removing the metal binder of the stirring head according to claim 1, wherein: the rotating speed of the stirring head is controlled at 500-1200 rpm.

8. The method for removing the metal binder of the stirring head according to claim 1, wherein: the residence time of the stirring head on the metal material removing plate is controlled to be 3-6 seconds.

9. The method for removing the metal binder of the stirring head according to claim 1, wherein: the stirring head is made of tungsten-rhenium alloy, cobalt alloy or PCBN, the metal binder is made of stainless steel, titanium alloy or pure titanium, and the metal material removing plate is made of low-carbon steel.

10. The method for removing the metal binder of the stirring head according to claim 1, wherein: the stirring head is made of steel, the metal binder is made of magnesium alloy, and the metal material removing plate is made of aluminum alloy.

Technical Field

The invention relates to the technical field of friction stir welding, in particular to a method for removing metal bonding materials of a stirring head.

Background

Friction welding, as a novel solid phase joining technique, has been widely used for welding low melting point metals such as aluminum, magnesium, and copper, with the advantage of excellent structure properties. For high-melting-point materials such as steel and titanium, the excellent high-temperature strength causes the materials to be difficult to plasticize, so that higher requirements are put on the stirring head material, and the application of friction stir welding technology to the high-melting-point materials is limited. In recent years, with the obvious progress in the preparation of materials of stir heads such as tungsten-rhenium alloy, cobalt alloy and Polycrystalline Cubic Boron Nitride (PCBN) and the design of tools, the research on friction stir welding of high melting point metals is more and more extensive and deep.

In fact, during friction stir welding, a certain amount of metal binder typically adheres to the stir head surface. This is primarily related to the mutual movement or friction between the tool and the metal of the welding workpiece. In the welding process, the stirring head and the metal of a welding workpiece move mutually, and temperature rise and plastic deformation occur under the action of friction force, so that welding is performed under the action of molecular force. When the stirring head moves forwards, if the shearing occurs on the original contact surface, the abrasion or adhesion cannot occur; if the shear occurs on the metal side of the less strong weld workpiece, the higher strength tool surface will have high melting point material adhered to it and the metal bond will stick to the tool surface during repeated subsequent rubs. Therefore, the friction between the stir head and the metal of the welding workpiece is referred to as stick friction.

In the adhesion friction process, on one hand, the softening degree of the metal of the welding workpiece is gradually increased due to the temperature rise, so that the real contact area is increased, the molecular adsorption acting force between the stirring head and the metal of the welding workpiece is enhanced, and the friction coefficient is further increased; on the other hand, the increase of temperature causes a lower hardness shaped metal layer to appear on the surface of the high melting point material, and the thickness of the shaped metal layer increases with the increase of temperature, thereby causing a large amount of softened welding workpiece metal to adhere to the surface of the stirring tool. Thus, an increase in temperature increases the degree of softening and thickness of the softening layer metal, resulting in an increase in viscoplastic metal transfer with rotation.

However, metal binder is adhered to the surface of the stirring head, so that on one hand, the friction condition between the stirring head and a welding workpiece is changed, and further the heat input in the welding process and the quality of a welding joint are influenced; on the other hand, the maintenance difficulty of the adhesion stirring head is increased, and the welding efficiency is influenced. Therefore, a simple and effective method for removing the metal binder of the stirring head is especially important.

Disclosure of Invention

The purpose of the invention is: a simple and efficient method for removing metal sticky materials of a stirring head.

In order to achieve the purpose, the invention provides a method for removing metal binder of a stirring head, which comprises the stirring head and a metal material removing plate, wherein the surface of the stirring head is adhered with the metal binder, the melting point of the stirring head is higher than the melting points of the metal material removing plate and the metal binder, the friction coefficient between the stirring head and the metal material removing plate and the friction coefficient between the stirring head and the metal binder are both smaller than the friction coefficient between the metal material removing plate and the metal binder, the stirring head is continuously rotated and pricked into the metal material removing plate, the metal binder and the metal material removing plate are softened and mixed to form a metal mixture, and the stirring head is pulled out of the metal material removing plate after the stirring head stays for 3-8 seconds on the metal material removing plate.

Preferably, the method comprises the following steps:

step 1: the stirring head is rotationally inserted into the metal material removing plate, and the metal binder and the metal material removing plate are softened and generate plastic deformation;

step 2: the metal binder is separated from the stirring head, the metal binder and the metal material removing plate are mixed to form the metal mixture, and the metal mixture is positioned on the periphery of the surface of the stirring head;

and step 3: and drawing out the stirring head from the metal material removing plate.

Preferably, in the step 3, a metal mixture layer is formed on the metal material removing plate.

Preferably, in the step 2, the adhesive force between the molecules of the metal material removing plate and the molecules of the metal binder is greater than the mechanical engaging force between the metal binder and the stirring head.

Preferably, the stirring head comprises a stirring pin and a stirring head shaft shoulder, the stirring head shaft shoulder is positioned at the upper end of the stirring pin, a set pressing amount is set when the stirring head penetrates into the metal material removing plate, and the pressing amount is set to be 0.35-0.55 mm.

Preferably, the metal material removing plate is provided with a pre-drilled hole, the diameter of the pre-drilled hole is smaller than the maximum diameter of the stirring pin of the stirring head, and the stirring head penetrates into the pre-drilled hole.

Preferably, the rotating speed of the stirring head is controlled at 500-1200 rpm.

Preferably, the residence time of the stirring head on the metal material removing plate is controlled to be 3-6 seconds.

Preferably, the stirring head is made of tungsten-rhenium alloy, cobalt alloy or PCBN, the metal binder is made of stainless steel, titanium alloy or pure titanium, and the metal material removing plate is made of low-carbon steel.

Preferably, the stirring head is made of steel, the metal binder is made of magnesium alloy, and the metal stripper plate is made of aluminum alloy.

Compared with the prior art, the method for removing the metal binder of the stirring head has the beneficial effects that: the method comprises the steps of pricking metal binder adhered to the surface of a stirring head into a metal material removing plate along with the stirring head, enabling the metal binder adhered to the stirring head to fully react with the material removing plate, utilizing the difference of adhesive force between different metals due to molecular adsorption, and achieving removal of the metal binder on the surface of the stirring head due to the fact that the friction coefficient between the stirring head and the metal material removing plate and the friction coefficient between the stirring head and the metal binder are smaller than the friction coefficient between the metal material removing plate and the metal binder. On the one hand, the retention time of the stirring head on the metal material removing plate is too short, the generated heat is insufficient, the metal binder and the metal material removing plate cannot be mixed to form a metal mixture, and then the removal of the metal binder cannot be realized. On the other hand, along with the prolonging of the retention time of the stirring head on the metal material removing plate, the heat generated by friction between the stirring head and the metal material removing plate is increased, so that the metal mixture is adhered to the surface of the stirring head again, the retention time of the stirring head on the metal material removing plate is controlled to be 3-8 seconds, a smooth surface of the stirring head can be obtained, the influence of the stirring head on heat input in the welding process is reduced, the quality of a welding joint is effectively improved, the maintenance difficulty of the stirring head is reduced, and the welding efficiency is improved. The method for removing the adhered metal on the surface of the stirring head is simple and effective, has low cost, is easy to popularize, contributes to saving energy and enables the stirring head to be recycled.

Drawings

FIG. 1a is a schematic side view of a stirring head with a metal binder according to example 1 of the present invention.

FIG. 1b is a schematic axial angle diagram of a stirring head with a metal paste adhered thereto according to example 1 of the present invention.

Fig. 1c is a schematic top view of a stirring head with a metal binder according to example 1 of the present invention.

Fig. 1d is a schematic structural diagram of a side view of the stirring head after the metal binder is removed in embodiment 1 of the present invention.

Fig. 1e is a schematic structural diagram of the axial angle of the stirring head after the metal binder is removed in embodiment 1 of the present invention.

Fig. 1f is a schematic structural diagram of a top view of the stirring head after the metal binder is removed in embodiment 1 of the present invention.

FIG. 2a is a schematic view of a keyhole formed in friction stir welding of a stirring head adhered with a metal binder according to example 1 of the present invention.

FIG. 2b is a schematic diagram of the keyhole formed by the stirring head in the metal material removing plate in the embodiment 1 of the invention when the metal material is removed.

Fig. 3a is a side view of a stirring head with a metal binder according to example 2 of the present invention.

FIG. 3b is a schematic axial angle diagram of a stirring head with a metal binder according to example 2 of the present invention.

Fig. 3c is a schematic top view of a stirring head with a metal binder according to example 2 of the present invention.

FIG. 3d is a schematic diagram of the structure of the stirring head of example 2 of the present invention at a side view angle after the metal stripping plate stays for 2 seconds.

FIG. 3e is a schematic axial angle structure of the stirring head of example 2 of the present invention after the metal stripper plate stays for 2 seconds.

FIG. 3f is a schematic diagram of the top view of the stirring head of example 2 of the present invention after the metal stripper plate stays for 2 seconds.

FIG. 3g is a schematic diagram of the structure of the stirring head of example 2 of the present invention at a side view angle after the metal material removing plate stays for 3 seconds.

FIG. 3h is a schematic diagram of the axial angle structure of the stirring head of example 2 of the present invention after the metal material removing plate stays for 3 seconds.

FIG. 3i is a schematic structural diagram of a top view angle of a stirring head in example 2 of the present invention after the metal material removing plate stays for 3 seconds.

FIG. 4a is a schematic view of a keyhole formed in friction stir welding of a stirring head adhered with a metal binder according to example 2 of the present invention.

FIG. 4b is a schematic diagram of the keyhole formed when the stirring head stays in the metal material removing plate for 2 seconds to remove the metal bonding material in the embodiment 2 of the invention.

FIG. 4c is a schematic diagram of the keyhole formed when the stirring head stays in the metal material removing plate for 3 seconds to remove the metal binder in the embodiment 2 of the invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. used herein are used to indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "connected," "fixed," and the like are used in a broad sense, and for example, the terms "connected," "connected," and "fixed" may be fixed, detachable, or integrated; the connection can be mechanical connection or welding connection; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 1a to 4c, the stirring head and the metal material removing plate are included, a metal binder is adhered to the surface of the stirring head, the melting point of the stirring head is higher than the melting points of the metal material removing plate and the metal binder, both the friction coefficient between the stirring head and the metal material removing plate and the friction coefficient between the stirring head and the metal binder are smaller than the friction coefficient between the metal material removing plate and the metal binder, the stirring head is continuously rotated and pricked into the metal material removing plate, the metal binder and the metal material removing plate are softened and mixed to form a metal mixture, and the stirring head is pulled out of the metal material removing plate after the metal material removing plate stays for 3 to 8 seconds.

The method for removing the metal binder of the stirring head comprises the steps of pricking the metal binder adhered to the surface of the stirring head into a metal material removing plate along with the stirring head, enabling the metal binder adhered to the stirring head to fully react with the material removing plate, and utilizing the difference of adhesive force between different metals caused by molecular adsorption, wherein the friction coefficient between the stirring head and the metal material removing plate and the friction coefficient between the stirring head and the metal binder are smaller than the friction coefficient between the metal material removing plate and the metal binder, so that the metal binder on the surface of the stirring head is removed. On the one hand, the retention time of the stirring head on the metal material removing plate is too short, the generated heat is insufficient, the metal binder and the metal material removing plate cannot be mixed to form a metal mixture, and then the removal of the metal binder cannot be realized. On the other hand, along with the overlong retention time of the stirring head on the metal material removing plate, the heat generated by friction between the stirring head and the metal material removing plate is increased, so that the metal mixture is adhered to the surface of the stirring head again, the retention time of the stirring head on the metal material removing plate is controlled to be 3-8 seconds, the smooth surface of the stirring head can be obtained, the influence of the stirring head on heat input in the welding process is reduced, the quality of a welding joint is effectively improved, the maintenance difficulty of the stirring head is reduced, and the welding efficiency is improved. The method for removing the adhered metal on the surface of the stirring head is simple and effective, has low cost, is easy to popularize, contributes to saving energy and enables the stirring head to be recycled.

Further, the method comprises the following steps:

step 1: the stirring head is rotationally inserted into the metal material removing plate, and the metal binder and the metal material removing plate are softened and generate plastic deformation; in the process that the stirring head rapidly rotates and pricks the metal material removing plate, friction is generated between the stirring head and the metal material removing plate, a large amount of heat is generated, and the metal adhesive material and the metal material removing plate are softened and generate plastic deformation.

Step 2: the metal binder is separated from the stirring head, the metal binder and the metal material removing plate are mixed to form the metal mixture, and the metal mixture is positioned on the periphery of the surface of the stirring head; along with the high-speed rotation of the stirring head, the heat generated by friction between the stirring head and the metal material removing plate is accumulated and increased, the metal material removing plate and the metal binder are mixed, the adhesive force between molecules of the metal material removing plate and molecules of the metal binder is gradually increased, and when the adhesive force between the molecules of the metal material removing plate and the metal binder is larger than the mechanical engaging force between the metal binder and the stirring head, the metal binder is separated from the stirring head.

And step 3: and drawing out the stirring head from the metal material removing plate. As shown in fig. 2b and fig. 4 b-fig. 4c, a metal mixture layer is formed in the metal material removing plate, the metal binder is mixed with the metal of the heated and softened part of the metal material removing plate to form the metal mixture layer, the stirring head is pulled out, as shown in fig. 1 d-1 f and fig. 3 d-fig. 3i, a smooth stirring head is obtained, and smooth spoon holes are formed on the surface of the metal material removing plate.

Furthermore, the melting point of the stirring head is at least 1100 ℃ higher than that of the metal bonding material or the metal material removing plate, so that the stirring head is prevented from softening or plastically deforming in the rotating heat generating process of the stirring head, and the removal efficiency and the removal degree of the metal bonding material are improved.

Furthermore, the stirring head comprises a stirring pin and a stirring head shaft shoulder, the stirring head shaft shoulder is located at the upper end of the stirring pin, the stirring head is inserted into the metal material removing plate and has a set pressing amount, and the pressing amount is the amount of continuing pressing the metal material removing plate after the stirring pin is completely pressed into the metal material removing plate. The pressing amount is set to 0.35-0.55 mm. The stirring pin is set with a pressing amount so as to ensure that the joint of the stirring pin and the shaft shoulder of the stirring head and the stirring pin are respectively in complete contact with the metal material removing plate, so that metal adhesive on the stirring head is fully reacted with the metal material removing plate, the metal adhesive completely falls off on the stirring head, and the stirring head with a smooth surface is formed.

Furthermore, a pre-drilled hole is formed in the metal material removing plate before the stirring head penetrates into the metal material removing plate, the inner wall profile of the pre-drilled hole is matched with the surface profile of the stirring head, and the stirring head penetrates into the pre-drilled hole. The metal material removing plate is provided with a pre-drilled hole, the stirring pin penetrates into the pre-drilled hole, only the side face of the stirring pin moves relative to the steel plate, and the stirring pin is not easy to break. The diameter of the pre-drilled hole is smaller than the maximum diameter of the stirring pin. When the stirring pin and the metal material removing plate vertically contact, the stirring pin can receive a large load, and the pin is easy to break. Because the stirring pin is the toper, the bottom orientation of stirring pin is pre-drilled, when the stirring pin pricks into pre-drilled hole, the bottom of stirring pin does not remove flitch vertical contact with the metal, the bottom of stirring pin has the certain distance with the bottom surface of pre-drilled hole when pricking, the side of stirring pin takes place to contact and produce heat with pre-drilled hole, and then guarantee that the bottom of stirring pin does not remove flitch direct contact with the metal under the condition that does not have any heat production, prevent the stirring pin fracture, effectively prolong the life-span of stirring head, improve the recycle rate of stirring head. After the stirring head rotates at a high speed and rubs with the metal material removing plate to generate heat, the metal material removing plate is softened, and then the bottom end of the stirring pin of the stirring head is contacted with the metal material removing plate. Preferably, the diameter of the pre-drilled hole is 0.5-0.7 times of the maximum diameter of the stirring pin, the depth of the pre-drilled hole is 0.6-0.7 times of the length of the stirring pin, so that the side face of the stirring pin is in contact with the metal material removing plate when the stirring pin is inserted into the pre-drilled hole, the bottom end of the stirring pin is at a certain distance from the bottom surface of the pre-drilled hole, the distance from the bottom end of the stirring pin to the bottom surface of the pre-drilled hole is moderate, heat is generated when the stirring pin rotates at a high speed, the metal material removing plate is softened, the pre-drilled hole is filled by the stirring pin in a short time, the stirring pin is fully contacted with the metal material removing plate, the metal binder is completely removed, and the removal efficiency of the metal binder is improved.

Further, the rotating speed of the stirring head is controlled at 500-1200 rpm. The higher the rotational speed of stirring head is, heat production efficiency is higher, and the time of staying on the metal removes the flitch is shorter, effectively improves the efficiency of getting rid of metal sizing.

Further, the residence time of the stirring head on the metal material removing plate is controlled to be 3-6 seconds. The dwell time of stirring head on the flitch is removed to the metal is short excessively, and the friction heat production between the flitch is removed to stirring head and metal is not enough, and the metal removes the flitch and softens not enough, leads to the metal sizing can not remove flitch fully contact and mix with the metal, and then makes the metal sizing get rid of the effect not good. The heat generated by friction between the stirring head and the metal material removing plate is increased along with the increase of the heat, so that the metal mixture is re-adhered to the surface of the stirring head, and the retention time of the stirring head on the metal material removing plate cannot be too long. The residence time of the stirring head on the metal material removing plate is controlled within a proper range, so that the removal efficiency of metal sticky materials can be improved, and the removal degree of the metal sticky materials is improved.

Further, the stirring head is made of tungsten-rhenium alloy, cobalt alloy or PCBN, the metal binder is made of stainless steel, titanium alloy or pure titanium, and the metal material removing plate is made of low-carbon steel. The stirring head made of the tungsten-rhenium alloy, the cobalt alloy or the PCBN is suitable for friction stir welding of high-melting-point materials, the manufacturing cost of the stirring head made of the tungsten-rhenium alloy, the cobalt alloy or the PCBN is high, when the stainless steel, the titanium alloy or the PCBN is welded, the stainless steel, the titanium alloy or the pure titanium is easily adhered to the surface of the stirring head, the low-carbon steel material is low in price, the friction coefficient of the stirring head made of the low-carbon steel and the tungsten-rhenium alloy, the cobalt alloy or the PCBN is lower than that of the low-carbon steel and the stainless steel, the titanium alloy or the pure titanium, and therefore the cost for removing metal bonding materials made of the stainless steel, the titanium alloy or the pure titanium through the metal material removing plate made of the low-carbon steel material is low, and the efficiency is high.

Further, the stirring head is made of steel, the metal binder is made of magnesium alloy, and the metal material removing plate is made of aluminum alloy. The stirring head is made of steel materials, and the stirring head is directly discarded when metal binder is adhered to the stirring head and normal welding cannot be realized due to the low manufacturing cost of the stirring head. The iron and steel stirring head rotates on the aluminum alloy metal material removing plate at a high speed to remove magnesium alloy metal adhesive materials, so that the iron and steel stirring head can be recycled, the material waste is reduced, and the energy is saved.

Example 1

Two stainless steel plates with the thickness of 6.0mm are welded in a butt joint mode by adopting a friction stir welding method, the diameter of a shaft shoulder of the tungsten-rhenium alloy stirring head is 21mm, the diameter of a stirring pin is 7.5mm, and the length of the stirring pin is 5.7 mm. As shown in FIGS. 1a to 1c, a large amount of metallic cement of stainless steel material is adhered to the shoulder of the pin and the pin, and the keyhole is caused to take the shape of a funnel as shown in FIG. 2 a. And (3) rotatably inserting the stirring head adhered with the stainless steel material metal binder into the low-carbon steel metal material removing plate at the rotating speed of 800rpm, the pressing amount of 0.5mm and the retention time of 8 seconds. As shown in fig. 1 d-1 f, the metallic material adhered around the stirring head is significantly removed and a smooth keyhole is formed, as shown in fig. 2 b. Preferably, the metal material removing plate in the embodiment is a 30# steel plate.

Example 2

Two pure titanium thick plates with the thickness of 6.0mm are welded in a butt joint mode by adopting a friction stir welding method, the diameter of a shaft shoulder is 19mm, the diameter of a stirring pin is 8mm, and the length of the stirring pin is 5.6 mm. As shown in fig. 3 a-3 c, a large amount of pure titanium metal cement adheres to the shoulder of the pin and the pin, and causes the keyhole to be funnel-shaped as shown in fig. 4 a. The tungsten-rhenium alloy stirring head adhered with a large amount of pure titanium metal bonding materials is rotatably inserted into a low-carbon steel metal material removing plate, the rotating speed is 500rpm, the pressing amount is 0.45mm, and the retention time is 2 seconds. As shown in fig. 3 d-3 f, the material adhered around the pin is significantly removed, but a certain amount of pure titanium metal paste is adhered to the shoulder where it is connected to the pin, and a relatively smooth keyhole is formed, as shown in fig. 4 b. Subsequently, the hold-down was adjusted to 0.55mm and the dwell time was changed to 3 seconds and after a second friction stir spot weld of # 30 steel plate, it was found that substantially all of the adhering pure titanium around the pin was removed and formed smooth keyholes as shown in FIGS. 3 g-3 i and in FIG. 4 c. Preferably, the metal material removing plate in the embodiment is a 30# steel plate.

Example 3

Two AZ31 magnesium alloy plates with the thickness of 4.0mm are welded in a butt joint mode by adopting a friction stir welding method, the diameter of a shaft shoulder of a stirring head is 21mm, the diameter of a stirring pin is 4.2mm, and the length of the stirring pin is 3.7 mm. The shaft shoulder of the stirring head and the stirring needle are adhered with a large amount of magnesium alloy metal adhesive, the steel stirring head adhered with the magnesium alloy metal adhesive is rotatably inserted into a 6061 aluminum alloy metal material removing plate, the rotating speed is 1200rpm, the pressing amount is 0.35mm, and the retention time is 4 seconds. The material adhering around the stirring head is removed.

Example 4

Two titanium alloys with the thickness of 5.0mm are welded in a butt joint mode by adopting a friction stir welding method, the diameter of a shaft shoulder of a cobalt alloy stirring head is 20mm, the diameter of a stirring pin is 10mm, and the length of the stirring pin is 4.7 mm. A large amount of titanium alloy metal adhesive materials are adhered to the shaft shoulder of the stirring head and the stirring pin. And (3) rotatably inserting the cobalt alloy stirring head adhered with the titanium alloy metal binder into a 30# steel plate metal material removing plate, wherein the rotating speed is 800rpm, the pressing amount is 0.5mm, and the retention time is 5 seconds. And removing the metal binder adhered to the periphery of the cobalt alloy stirring head.

Example 5

Two stainless steel plates with the thickness of 2.0mm are welded in a butt joint mode by adopting a friction stir welding method, the diameter of a shaft shoulder of a PCBN stirring head is 15mm, the diameter of a stirring pin is 5.1mm, and the length of the stirring pin is 1.7 mm. A large amount of stainless steel metal adhesive materials are adhered to the shaft shoulder of the stirring head and the stirring needle. The PCBN stirring head adhered with the stainless steel metal binder is rotatably inserted into a No. 30 steel plate metal material removing plate, the rotating speed is 800rpm, the pressing amount is 0.5mm, and the retention time is 5 seconds. And removing the metal binder adhered to the periphery of the PCBN stirring head.

To sum up, the embodiment of the present invention provides a method for removing a metal binder of a stirring head, wherein a melting point of the stirring head is higher than melting points of a metal material removing plate and the metal binder, a friction coefficient between the stirring head and the metal material removing plate and a friction coefficient between the stirring head and the metal binder are both smaller than a friction coefficient between the metal material removing plate and the metal binder, the stirring head is continuously rotated and pricked into the metal material removing plate, the metal binder and the metal material removing plate are softened and mixed to form a metal mixture, and after the stirring head is pricked into the metal material removing plate and stays for 3 to 8 seconds, the stirring head is pulled away from the metal material removing plate, so that the metal binder can be removed.

The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.