Thermoplastic composite metal layup laser welding method and apparatus

Abstract

The application provides a thermoplastic composite metal strip laying laser welding method and device, and realizes butt welding between thermoplastic composites. The method comprises the following steps: preparing a microstructure on the surface of a metal strip; laying the metal strip to a butt welding position of the composites; and conducting heat conduction welding on the metal strip and the composites by using a laser. When welding, two rollers are pressed on both sides of a laser spot, the two rollers move along with the laser spot, the front roller is used for laying and positioning the metal strip, the surface of the composite is melted by the laser, the rear roller applies pressure to the metal strip, the melted composite enters the microstructure on the surface of the metal strip, and a connecting joint is formed after cooling. The method has the advantages of high welding efficiency, no need to rely on the technology of workers, short production cycle, simple structure, easy operation and wide application range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser welding, and particularly relates to a thermoplastic composite material metal strip laying laser butt welding method and device. BACKGROUND

[0002] Composite materials are widely used in vehicle manufacturing industry, electromechanical industry, chemical corrosion prevention and building engineering and the like due to low density, high specific strength, impact resistance, wide design performance range, strong heat resistance, strong chemical corrosion resistance, good electrical conductivity and no pollution. At present, the connection of composite materials is mainly achieved by traditional mechanical connection and adhesive bonding method. The mechanical connection completely depends on manual operation, and the product quality is closely related to the technology of the workers. The production cycle is long. The adhesive bonding method needs pre-impregnated adhesive cloth, and the whole process is complicated, long in cycle and low in efficiency. As a non-contact welding technology, laser welding has great application potential in realizing high-strength, low-stress and long-life connection of composite materials. At present, laser welding mainly focuses on the welding between composite materials and metal materials, and relevant patents have been granted (such as ZL201510014414.4 and ZL201610254547.3). Due to the sensitivity of composite materials to laser heat input and the fact that laser cannot penetrate composite materials, laser welding between composite materials is still a difficult problem, especially laser butt welding between composite materials, which is more challenging. Although the patent (CN202310476307.8) proposes a method and device for laser butt welding of composite materials, the method is only suitable for welding of small-size test pieces, and the process is complicated, so that butt welding between large-size composite material parts cannot be realized, and the flexibility, flexibility and automation degree cannot meet the needs of engineering application. SUMMARY

[0003] In order to solve the above problems, the application discloses a thermoplastic composite material metal strip laying laser welding method, and based on the method, a metal strip laying welding device is proposed. The whole welding process is realized by automatic operation. The metal strip is laid on the butt joint position of the composite material plate. The metal strip is heated by a laser to connect the metal and the composite material together, so as to complete the butt welding between the composite materials. The welding efficiency is high, and the production cycle is short without relying on the technology of the workers.

[0004] A thermoplastic composite material metal strip laying laser butt welding method, and the specific steps are as follows,

[0005] Microstructures are prepared on the surface of the metal strip;

[0006] The metal strip is laid on the butt welding position of the composite material to be welded;

[0007] The metal strip and the composite material are welded by heat conduction of laser, two rollers are pressed on both sides of the laser spot during welding, the two rollers move along with the laser spot, the front roller is used for laying and positioning the metal strip, the laser melts the resin matrix on the surface of the composite material, the rear roller applies pressure to the metal strip, so that the melted composite material enters the microstructure on the surface of the metal strip, and a connecting joint is formed after cooling.

[0008] Further, after step (3), it further comprises step (4): turning over the composite material welded in step (3), and repeating steps (2) and (3).

[0009] Further, the metal strip is titanium alloy or aluminum alloy or stainless steel or copper alloy or magnesium alloy.

[0010] Further, the main processing method for preparing the microstructure of the metal strip in step (1) is mechanical tool processing or shot blasting processing or sand blasting processing or laser micro-processing or electrical processing or metal embossing processing.

[0011] Further, the thermoplastic composite material is carbon fiber reinforced thermoplastic composite material or aramid fiber reinforced thermoplastic composite material or glass fiber reinforced thermoplastic composite material.

[0012] Further, the laser spot in step (3) is a linear spot or a rectangular spot.

[0013] Further, in step (3), the distance between the centers of the two rollers is d, the radius of the roller is r, if a linear spot is used, then d-2r ≥ D, and the length L of the linear spot is equal to the width of the metal strip; if a rectangular spot is used, then d-2r ≥ W, and the length L of the rectangular spot is equal to the width of the metal strip; wherein D is the diameter of the spot, W is the width of the rectangular spot, and L is the length of the spot.

[0014] The application also provides a metal strip welding device for a thermoplastic composite material metal strip laser welding method, comprising:

[0015] A mechanical arm;

[0016] A support connected to the mechanical arm and moving under the drive of the mechanical arm;

[0017] Two telescopic rods telescopically installed on the support and spaced apart;

[0018] Two rollers respectively arranged at the ends of the telescopic rods;

[0019] A laser head arranged on the support between the two telescopic rods;

[0020] A strip feeder arranged on the support and used for conveying the metal strip.

[0021] Further, the laser is a fiber laser or a CO2 laser or a semiconductor laser.

[0022] The beneficial effects of the present application are as follows:

[0023] 1. The present application designs a metal taping method, which heats the metal taping at the butt joint of the composite material plate through a laser head, melts the thermoplastic resin on the surface of the composite material through the principle of heat conduction, and realizes the connection of the metal taping and the composite material plate when cooled to room temperature, thereby realizing more stable connection between the composite material plates.

[0024] 2. The present application designs a metal taping device, which cooperates the metal taping device, the metal taping device, the metal taping device, and the metal taping device to place the metal taping at the butt joint position of the composite material plate, and appropriately press the composite material plate, thereby realizing automatic operation, saving manpower, and improving work efficiency.

[0025] In summary, the method and device of the present application have simple structure, easy operation, high welding efficiency, and wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The metal taping welding method principle diagram of the embodiment of the present application;

[0027] Figure 2 The laser spot working requirement diagram of the embodiment of the present application;

[0028] Figure 3 The metal taping embossing processing of the embodiment of the present application;

[0029] Figure 4 The embodiment of the present application is the overall structure diagram of the metal taping welding device of the present application.

[0030] 1, embossing roller; 2, microstructure; 3, pressure roller; 4, metal tape; 5, mechanical arm; 6, support; 7, pneumatic adjusting telescopic rod; 8, pressure roller; 9, composite material plate; 10, positioning roller; 11, metal tape; 12, tape feeder; 13, laser head. DETAILED DESCRIPTION

[0031] Please refer to Figure 4 The embodiment of the present application provides a metal taping welding device for thermoplastic composite material metal taping laser welding method, which comprises:

[0032] Mechanical arm 5;

[0033] Support 6 connected to the mechanical arm 5 and moving under the driving of the mechanical arm 5;

[0034] Two telescopic rods 7 are telescopically mounted on the bracket 6, and are spaced apart;

[0035] Two rollers 8, 10 are respectively arranged at the ends of the telescopic rods 7.

[0036] A laser head 13 is arranged on the bracket 6 between the two telescopic rods 7.

[0037] A tape feeder 12 is arranged on the bracket 6 for feeding the metal tape 11.

[0038] The telescopic rod 7 is a pneumatic telescopic rod, which can adjust the telescopic length of the rod 7, the defocusing amount of the laser head 13, and the pressure applied by the rollers 8, 10 on the metal tape 11 through air pressure.

[0039] The rollers 8, 10 are respectively a positioning roller 10 and a pressure roller 8.

[0040] The laser is a fiber laser, a CO2 laser, or a semiconductor laser.

[0041] Please refer to Figure 1 , the welding process includes:

[0042] Preparation of the microstructure on the surface of the metal tape 4.

[0043] Please refer to Figure 3 , the microstructure 2 of the metal tape 4 is made. Specifically, a special roller 1 is specified to prepare a mesh microstructure 2 on the surface of the metal tape 4 by a metal embossing process, forming a microstructure 2 with a depth and width of 0.1 mm, and the interval of the microstructure 2 is 0.1 mm.

[0044] After the preparation is completed, a metal tape 11 with a microstructure is obtained ( Figure 4 ), which is wound on the tape feeder 12 for subsequent use.

[0045] For ease of illustration, the metal tape 4 is shown in the accompanying drawings, which is a metal tape without the microstructure 2; the metal tape 11 in the accompanying drawings is a metal tape with the microstructure 2. Figure 3 Figure 4

[0046] The metal tape 11 is laid on the butt-welding part of the composite material to be welded.

[0047] The two composite materials to be welded are closely arranged, and the adjacent parts are the parts to be welded.

[0048] ​​The laser emitted by the laser head 13 conducts heat to the metal strip 11 and the composite material, and the two rollers 8, 10 are pressed on both sides of the laser spot during welding. The two rollers 8, 10 move along with the laser spot. The front roller 10 is used for laying and positioning the metal strip 11. The laser melts the surface of the composite material. The rear roller 8 applies pressure to the metal strip, so that the melted composite material enters the microstructure 2 on the surface of the metal strip 11 and forms a connecting joint after cooling.

[0049] As shown in Figure 2 , the metal strip 11 is laid on the butt joint position of the composite material plate 9 by the cooperation of the mechanical arm 5, the positioning wheel 10, the pressing wheel 8 and the strip feeder 12. The metal strip 11 is welded with the composite material plate 9 by using a continuous laser with a wavelength of 1064 nm and a pulse width of 50 ms in a defocusing state. The interface thermoplastic resin layer is fully melted. The melted resin is embedded in the microstructure 2 prepared on the metal strip 11, which is bonded with the metal strip 11, and forms a joint after cooling, thereby stably connecting the composite material plate.

[0050] When the metal strip 11 and the composite material are welded on the first surface, the welded composite material is turned over and the welding operation is repeated to complete the welding of the two surfaces.

[0051] Further, the metal strip 4, 11 is titanium alloy or aluminum alloy or stainless steel or copper alloy or magnesium alloy.

[0052] Further, the main processing methods for preparing the microstructure 2 of the metal strip 4 in step (1) are mechanical tool processing, shot blasting processing, sand blasting processing, laser micro-processing, electrical processing or metal embossing processing.

[0053] Further, the thermoplastic composite material is carbon fiber reinforced thermoplastic composite material or aramid fiber reinforced thermoplastic composite material or glass fiber reinforced thermoplastic composite material.

[0054] Further, the laser spot is a linear spot or a rectangular spot.

[0055] Please refer to Figure 2 , further, the distance between the centers of the two rollers 8, 10 is d, and the radius of the roller is r. If a linear spot is used, d-2r ≥ D, and the length L of the linear spot is equal to the width of the metal strip. If a rectangular spot is used, d-2r ≥ W, and the length L of the rectangular spot is equal to the width of the metal strip 11. Wherein, D is the diameter of the spot, W is the width of the rectangular spot, and L is the length of the spot.

[0056] Finally, it should be noted that the above is only the preferred embodiment of the present application, and is not intended to limit the present application, although the embodiments are described in detail with reference to the present application, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced, but any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method of thermoplastic composite metal pultruded laser butt welding, characterized by: The specific steps are as follows, (1) preparing a microstructure on the surface of the metal strip; (2) laying the metal strip on the butt-welding position of the composite material to be welded; the two composite materials to be welded are abutted against each other at the position adjacent to the butt-welding position; (3) conducting heat conduction welding on the metal strip and the composite material by laser, and pressing the two rollers on both sides of the laser spot during welding, and moving the two rollers along with the laser spot; the front roller is used for laying and positioning the metal strip, the laser melts the resin matrix on the surface of the composite material, and the rear roller applies pressure to the metal strip, so that the melted composite material enters the microstructure on the surface of the metal strip, and a connecting joint is formed after cooling; (4) turning over the composite material after step (3), and repeating steps (2) and (3).

2. The method of thermoplastic composite metal pultruded strip laser butt welding of claim 1, wherein, The metal strip is titanium alloy or aluminum alloy or stainless steel or copper alloy or magnesium alloy.

3. The method of thermoplastic composite metal-ply laser butt welding of claim 1, wherein, The main processing methods for preparing the microstructure on the metal strip in step (1) are mechanical tool processing, shot blasting, sand blasting, laser micro-processing, electrical processing or metal embossing.

4. The method of thermoplastic composite metal pultruded strip laser butt welding of claim 1, wherein, The thermoplastic composite material is carbon fiber reinforced thermoplastic composite material or aramid fiber reinforced thermoplastic composite material or glass fiber reinforced thermoplastic composite material.

5. The method of thermoplastic composite metal pultruded strip laser butt welding of claim 1, wherein, The laser spot in step (3) is a linear spot or a rectangular spot.

6. The method of thermoplastic composite metal pultruded strip laser butt welding of claim 5, wherein, In step (3), the distance between the centers of the two rollers is d, the radius of the roller is r, if a linear spot is used, then d-2r≥D, and the length L of the linear spot is equal to the width of the metal strip; if a rectangular spot is used, then d-2r≥W, and the length L of the rectangular spot is equal to the width of the metal strip; wherein D is the diameter of the spot, W is the width of the rectangular spot, and L is the length of the spot.

7. A method for laser butt welding thermoplastic composite metal-ply laminates as claimed in any one of claims 1-6, characterized in that, It also includes a metal strip laying and welding device, which comprises: a mechanical arm; a support connected to the mechanical arm and moving under the drive of the mechanical arm; two telescopic rods telescopically installed on the support and spaced apart; two rollers respectively arranged at the ends of the telescopic rods; a laser head arranged on the support between the two telescopic rods; a belt feeder arranged on the support for conveying the metal strip.

8. The method of thermoplastic composite metal pultruded strip laser butt welding of claim 7, wherein, The laser is a fiber laser, a CO2 laser or a semiconductor laser.

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