阅读说明：本技术 一种层状金属复合板搅拌摩擦焊搅拌头、装置及焊接方法 (Stirring head, device and welding method for friction stir welding of layered metal composite plate ) 是由 陈洪胜 牛晓峰 池涵娟 巩鹏飞 王文先 郑凡林 于 2021-09-01 设计创作，主要内容包括：本发明提供了一种层状金属复合板搅拌摩擦焊搅拌头、装置及焊接方法,属于层状金属复合板加工的技术领域,是针对焊接层状复合板的弊端而设计的,采用高频脉冲电流加热、陶瓷绝缘套筒、锥形+球头式结构的搅拌头相结合的设计,在搅拌头上施加高频脉冲电流,使得层状金属复合板在搅拌摩擦焊焊接过程中实现局部加热,降低层状金属复合板的变形抗力,也可以减少金属间化合物的生成,搅拌头采用锥形+球头式结构,可以有效避免两种金属材料混合在一起,避免在层状金属复合板的界面处形成金属间化合物,同时又可以实现同一层金属的均匀混合,增强焊接接头的强度,提高产品质量和生产效率,是一种理想的用于焊接层状金属复合材料的焊接头。(The invention provides a stirring head, a device and a welding method for friction stir welding of a layered metal composite plate, which belong to the technical field of processing of the layered metal composite plate, are designed aiming at the defects of welding the layered composite plate, adopt the design of high-frequency pulse current heating, a ceramic insulating sleeve and a conical and ball head type structure of the stirring head, and apply the high-frequency pulse current on the stirring head, so that the layered metal composite plate realizes local heating in the friction stir welding process, the deformation resistance of the layered metal composite plate is reduced, the generation of intermetallic compounds can also be reduced, the stirring head adopts the conical and ball head type structure, two metal materials can be effectively prevented from being mixed together, the intermetallic compounds are prevented from being formed at the interface of the layered metal composite plate, the uniform mixing of the same layer of metal can be realized, and the strength of a welding joint is enhanced, the product quality and the production efficiency are improved, and the welding head is an ideal welding head for welding the laminated metal composite material.)

1. A stirring head for friction stir welding of a layered metal composite plate is characterized by comprising a stirring head body, a ceramic insulating sleeve, a slip ring and a stirring pin;

the ceramic insulating sleeve is fixedly sleeved on the top of the stirring head body;

the slip ring is sleeved on the stirring head body through clearance fit and is connected with the positive electrode of the high-frequency pulse power supply through the electric brush;

the stirring pin is fixed on the bottom surface of the stirring head body and sequentially comprises a conical stirring pin surface used for being in contact with an upper layer material of the layered metal composite plate to be welded, a stirring pin fractal groove used for dividing the upper layer material and the lower layer material of the layered metal composite plate to be welded and a stirring pin spherical head used for being in contact with a lower layer material of the layered metal composite plate to be welded from top to bottom;

The diameter of the conical surface of the stirring needle is gradually reduced from top to bottom;

the ball-shaped head of the stirring pin is a drum-shaped ball head.

2. The friction stir welding tool of claim 1, wherein the angle between the inclined plane of the conical surface of the pin and the bottom surface of the tool body is 72 °, and the radius of the arc of the spherical head of the pin is 3 mm.

3. The layered metal composite plate friction stir welding tool of claim 2, wherein the tool body and the pin are both made of tungsten-rhenium alloy and have a surface roughness of Ra 1.6.

4. The layered metal composite plate friction stir welding tool of any one of claims 1-3, wherein the bottom edge of the tool body is provided with a tool shoulder.

5. The layered metal composite plate friction stir welding tool of claim 4, wherein the slip ring is proximate to the tool shoulder.

6. The friction stir welding tool of claim 1, wherein the ceramic insulating sleeve is in interference fit with the tool body and is circumferentially fixed by a flat key.

7. The layered metal composite plate friction stir welding tool of claim 6 wherein the ceramic insulating sleeve is made of a composite of aluminum oxide and silicon nitride and has an inner diameter with a surface roughness of Ra 3.2.

8. The layered metal composite plate friction stir welding tool of claim 7 wherein the flat key is formed of 45 steel and the working surface has a surface roughness of Ra 3.2.

9. A friction stir welding device for laminar metal composite plates, which is characterized by comprising a high-frequency pulse power supply, a ceramic insulating base plate for placing the laminar metal composite plates to be welded and a friction stir welding stirring head for laminar metal composite plates according to any one of claims 1 to 8;

the positive pole of the high-frequency pulse power supply is connected with the electric brush on the slip ring through a lead, and the negative pole of the high-frequency pulse power supply is connected with the electric brush on the lower-layer material of the layered metal composite plate to be welded through a lead;

the ceramic insulating pad plate is made of a composite material of aluminum oxide and silicon nitride.

10. A friction stir welding method for a layered metal composite plate is characterized in that the layered metal composite plate to be welded is an Al/Mg layered metal composite plate, the layered metal composite plate to be welded is fixed on a ceramic insulating base plate, and the welding parameters of the friction stir welding device for the layered metal composite plate according to claim 9 are set to be 1300 r/min of the rotation speed of a stirring head, 0.6 mm of pressing amount, 70 mm/min of welding speed, 18V of pulse voltage, 100 Hz of pulse frequency and 50% of pulse duty ratio.

Technical Field

The invention belongs to the technical field of processing of layered metal composite plates, and particularly discloses a stirring head, a stirring device and a welding method for friction stir welding of a layered metal composite plate.

Background

The layered metal composite plate is formed by combining two different types of metals together in a heating, pressurizing and other modes. The layered metal composite plate has the characteristics of two metal materials, such as a magnesium/aluminum composite plate, a magnesium/copper composite plate, a carbon steel/stainless steel composite plate and the like, and has wide application prospects in the fields of aerospace, nuclear power military industry, electronics and electricians and automobile manufacturing.

At present, the methods for preparing the layered metal composite plate mainly comprise a rolling method, a semi-solid rolling method, an explosive welding and compounding method and the like. However, due to the difference in physical and chemical properties between the two plate materials in the layered metal composite plate, it is difficult to connect the layered composite plate together by using the conventional fusion welding method, and voids and intermetallic compounds are easily formed at the welded joint, thereby reducing the performance of the welded joint.

The friction stir welding method belongs to a solid phase connection method, has low welding temperature and high welding speed in the welding process, is a relatively applicable connection method for the layered metal composite plate, adopts a general friction stir welding stirring head to easily generate a large amount of intermetallic compounds at the welding joint in the welding process, has high energy consumption in the welding process, and brings certain difficulty to the welding of the layered metal composite plate.

Disclosure of Invention

The invention aims to provide a stirring head, a device and a welding method for friction stir welding of a layered metal composite plate.

In order to achieve the aim, the invention provides a stirring head for friction stir welding of a layered metal composite plate, which comprises a stirring head body, a ceramic insulating sleeve, a slip ring and a stirring pin, wherein the ceramic insulating sleeve is arranged on the stirring head body; the ceramic insulating sleeve is fixedly sleeved on the top of the stirring head body; the slip ring is sleeved on the stirring head body through clearance fit and is connected with the positive electrode of the high-frequency pulse power supply through the electric brush; the stirring pin is fixed on the bottom surface of the stirring head body and sequentially comprises a conical stirring pin surface used for being in contact with an upper layer material of the layered metal composite plate to be welded, a stirring pin fractal groove used for dividing the upper layer material and the lower layer material of the layered metal composite plate to be welded and a stirring pin spherical head used for being in contact with a lower layer material of the layered metal composite plate to be welded from top to bottom; the diameter of the conical surface of the stirring needle is gradually reduced from top to bottom; the ball-shaped head of the stirring pin is a drum-shaped ball head.

Furthermore, an included angle between the inclined plane of the conical surface of the stirring pin and the bottom surface of the stirring head body is 72 degrees, and the arc radius of the spherical head of the stirring pin is 3 mm.

Further, the stirring head body and the stirring pin are both made of tungsten-rhenium alloy, and the surface roughness is Ra 1.6.

Further, the bottom surface edge of stirring head body is provided with the stirring head shaft shoulder.

Further, the slip ring is close to the shaft shoulder of the stirring head.

Further, interference fit between ceramic insulation sleeve and the stirring head body is fixed through flat key circumference.

Further, the ceramic insulating sleeve is made of a composite material of aluminum oxide and silicon nitride, and the surface roughness of the inner diameter of the ceramic insulating sleeve is Ra 3.2.

Further, the flat key is made of 45 steel, and the surface roughness of the working surface is Ra 3.2.

The invention also provides a stirring friction welding device for the layered metal composite plate, which comprises a high-frequency pulse power supply, a ceramic insulating base plate for placing the layered metal composite plate to be welded and a stirring head for stirring friction welding of the layered metal composite plate; the positive pole of the high-frequency pulse power supply is connected with the electric brush on the slip ring through a lead, and the negative pole of the high-frequency pulse power supply is connected with the electric brush on the lower-layer material of the layered metal composite plate to be welded through a lead; the ceramic insulating pad plate is made of a composite material of aluminum oxide and silicon nitride.

The invention also provides a friction stir welding method of the layered metal composite plate, the layered metal composite plate to be welded is an Al/Mg layered metal composite plate, the layered metal composite plate to be welded is fixed on the ceramic insulating base plate, and the welding parameters of the friction stir welding device of the layered metal composite plate are set to be 1300 r/min of the rotating speed of the stirring head, 0.6 mm of the pressing amount, 70 mm/min of the welding speed, 18V of pulse voltage, 100 Hz of pulse frequency and 50% of pulse duty ratio.

The invention has the following advantages:

compared with the prior art, the invention has obvious advancement, is designed aiming at the defects of welding the layered composite plate, adopts the design of combining high-frequency pulse current heating, a ceramic insulating sleeve and a stirring head with a cone-shaped and ball-head type structure, realizes local heating of the layered metal composite plate in the friction stir welding process by the high-frequency pulse current heating, reduces the deformation resistance of the layered metal composite plate, can effectively prevent two metal materials from being mixed together by the cone-shaped and ball-head type structure, avoids forming intermetallic compounds at the interface of the layered metal composite plate, enhances the strength of a welding joint, and improves the product quality and the production efficiency.

Drawings

FIG. 1 is an overall structure diagram of a friction stir welding head of a layered metal composite plate;

FIG. 2 is a top view of a ceramic insulator sleeve;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is an enlarged view of the pin stirrer;

FIG. 5 is a metallic phase diagram of a welded joint of the aluminum-magnesium layered metal composite plate;

in the figure: 1-ceramic insulating sleeve, 2-flat key, 3-slip ring, 4-stirring head shaft shoulder, 5-layered metal composite plate to be welded, 6-ceramic insulating base plate, 7-stirring needle conical surface, 8-stirring needle fractal groove, 9-stirring needle spherical head, 10-high frequency pulse power supply and 11-electric brush.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment provides a stirring head for friction stir welding of a layered metal composite plate, which comprises a stirring head body, a ceramic insulating sleeve 1, a slip ring 3 and a stirring pin; the ceramic insulating sleeve 1 is fixedly sleeved at the top of the stirring head body; the slip ring 3 is sleeved on the stirring head body in a clearance fit manner, is connected with the positive electrode of the high-frequency pulse power supply 10 through the electric brush 11 and supplies power to the stirring pin; the stirring pin is fixed on the bottom surface of the stirring head body and sequentially comprises a stirring pin conical surface 7 used for being in contact with an upper layer material of the layered metal composite plate to be welded, a stirring pin fractal groove 8 used for dividing the upper layer material and the lower layer material of the layered metal composite plate to be welded and a stirring pin spherical head 9 used for being in contact with a lower layer material of the layered metal composite plate to be welded from top to bottom; the diameter of the conical surface 7 of the stirring pin is gradually reduced from top to bottom; the stirring pin ball head 9 is a drum-shaped ball head.

Furthermore, the included angle between the inclined plane of the conical surface 7 of the stirring pin and the bottom surface of the stirring head body is 72 degrees, and the arc radius of the spherical head 9 of the stirring pin is 3 mm.

Further, the stirring head body and the stirring pin are both made of tungsten-rhenium alloy, and the surface roughness is Ra 1.6.

Further, the bottom surface edge of the stirring head body is provided with a stirring head shaft shoulder 4.

Further, the slip ring 3 is close to the pin shoulder 4.

Further, interference fit between ceramic insulating sleeve 1 and the stirring head body is fixed through flat key 2 circumference. The flat key 2 plays a role in enabling the ceramic insulating sleeve 1 and the stirring head body and the stirring pin to jointly make rotary motion in the friction stir welding process, the ceramic insulating sleeve 1 is firmly assembled with a main shaft of friction stir welding equipment, and the rotary motion is transmitted to the stirring head body and the stirring pin through the flat key 2.

Further, the ceramic insulating sleeve 1 is made of a composite material of aluminum oxide and silicon nitride, and the surface roughness of the inner diameter of the ceramic insulating sleeve 1 is Ra 3.2.

Further, the flat key 2 is preferably made of 45 steel, and the surface roughness of the working surface is Ra 3.2.

Example 2

The embodiment provides a friction stir welding device for a layered metal composite plate, which comprises a high-frequency pulse power supply 10, a ceramic insulating base plate 6 for placing a layered metal composite plate 5 to be welded and a friction stir welding stirring head for the layered metal composite plate in the embodiment 1; the positive pole of a high-frequency pulse power supply 10 is connected with an electric brush 11 on the slip ring 3 through a lead, and the negative pole of the high-frequency pulse power supply is connected with the electric brush 11 on the lower-layer material of the layered metal composite plate 5 to be welded through a lead; the ceramic insulating pad 6 is made of a composite material of alumina and silicon nitride.

The ceramic insulating sleeve 1 and the ceramic insulating base plate 6 play an insulating role in the friction stir welding process, so that high-frequency pulse current can flow back to the cathode of the high-frequency pulse power supply 10 from the anode of the high-frequency pulse power supply 10 through the electric brush 11, the slip ring 3, the stirring head shaft shoulder 4, the stirring needle conical surface 7, the stirring needle fractal groove 8, the stirring needle spherical head 9, the layered metal composite plate 5 to be welded and the electric brush 11 to form a current loop.

Example 3

The embodiment provides a friction stir welding method for a layered metal composite plate, wherein a to-be-welded layered metal composite plate 5 is an Al/Mg layered metal composite plate, the surface of the to-be-welded layered metal composite plate 5 is firstly polished by using sand paper, then the surface of the to-be-welded layered metal composite plate is wiped completely by using alcohol, the to-be-welded layered metal composite plate 5 is fixed on a ceramic insulation backing plate 6 by using a fixture, and the welding parameters of the friction stir welding device for a layered metal composite plate described in the embodiment 2 are set to be that the rotating speed of a stirring head is 1300 r/min, the pressing amount is 0.6 mm, the welding speed is 70 mm/min, the pulse voltage is 18V, the pulse frequency is 100 Hz, and the pulse duty ratio is 50%.

During welding, the conical surface 7 of the stirring pin is in contact with the upper layer material of the layered metal composite plate to be welded, the parting groove 8 of the stirring pin is positioned at the joint interface of the layered metal composite plate 5 to be welded to realize the boundary of the upper layer material and the lower layer material, the spherical head 9 of the stirring pin is in contact with the lower layer material of the layered metal composite plate to be welded to realize the welding of the lower layer material

After welding, the metallographic structure of the welded joint is observed, the defects of tunnel holes, air holes, cracks and the like do not appear in the welded joint, and the welded joint is formed well.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.