阅读说明：本技术 一种多光束激光焊接纳米改性铝合金的方法及其装置 (Method and device for multi-beam laser welding of nano modified aluminum alloy ) 是由 马恒 徐爱民 柯定芳 汤超 何卫 王利民 董飞 张志猛 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种多光束激光焊接纳米改性铝合金的方法及装置,该方法包括：将光束通过分光装置沿焊接方向依次分为清洗光束、毛化光束和焊接光束；待焊接工件依次进入激光清洗区域、激光毛化区域和激光焊接区域一体化完成焊接,从而减少了焊接预处理所需的时间,提升激光焊接效率。(The invention discloses a method and a device for multi-beam laser welding of nano modified aluminum alloy, wherein the method comprises the following steps: the light beam is divided into a cleaning light beam, a texturing light beam and a welding light beam in sequence along the welding direction by a light splitting device; the workpieces to be welded sequentially enter the laser cleaning area, the laser texturing area and the laser welding area to be integrally welded, so that the time required by welding pretreatment is reduced, and the laser welding efficiency is improved.)

1. A method for laser welding nanometer modified aluminum alloy by multiple beams is characterized in that: the method comprises the following steps:

the light beam is divided into a cleaning light beam, a texturing light beam and a welding light beam in sequence along the welding direction by a light splitting device;

the workpiece to be welded sequentially enters a laser cleaning area, a laser texturing area and a laser welding area to be integrally welded; wherein the content of the first and second substances,

when the workpiece to be welded enters a laser cleaning area, cleaning the surface of the workpiece to be welded by a cleaning beam;

when the workpiece to be welded enters the laser texturing area, the texturing light beam increases the roughness of the surface of the cleaned workpiece to be welded;

and when the workpiece to be welded enters the laser welding area, welding the workpiece to be welded by the welding beam.

2. The method of multiple-beam laser welding nano modified aluminum alloy according to claim 1, wherein: the power of the cleaning light beam is 10-60W, the swing amplitude of the cleaning light beam is-10 mm, the scanning speed of the cleaning light beam is 500-2000 mm/s, and the repetition frequency of the cleaning light beam is 80-100 kHz;

the power of the textured light beam is 80-200W, the swing amplitude of the textured light beam is-5 mm, the scanning speed of the textured light beam is 6000-8000 mm/s, and the repetition frequency of the textured light beam is 10-20 kHz;

the power of the welding beam is 0-10000W, and the wavelength of the welding beam is 532 nm.

3. The method of multiple-beam laser welding nano modified aluminum alloy according to claim 1, wherein: the workpiece to be welded is any one of an aluminum alloy workpiece, an aluminum magnesium alloy workpiece and a titanium alloy workpiece.

4. A light splitting device, characterized in that: the device comprises a welding head shell (1), wherein an optical fiber pipeline (1.1) is arranged at the top of the welding head shell (1), and a cleaning beam separation assembly (2), a texturing beam separation assembly (3) and a welding beam separation assembly (4) are sequentially arranged on a line, which is formed by light beams released by the optical fiber pipeline (1.1) and enters the welding head shell (1).

5. The light-splitting device according to claim 4, wherein: the cleaning beam separation component (2) comprises a cleaning beam reflecting mirror (2.1), a cleaning beam vibrating mirror (2.2) with a rotating motor and a cleaning beam focusing mirror (2.3); the separated first beam of light beam sequentially irradiates a cleaning beam reflecting mirror (2.1), a cleaning beam vibrating mirror (2.2) and a cleaning beam focusing mirror (2.3) to obtain a cleaning beam;

the frosted light beam separation component (3) comprises a frosted light beam reflecting mirror (3.1), a frosted light beam vibrating mirror (3.2) with a rotating motor and a frosted light beam focusing mirror (3.3); the separated second light beam is sequentially emitted to a texturing light beam reflecting mirror (3.1), a texturing light beam vibrating mirror (3.2) and a texturing light beam focusing mirror (3.3) to obtain a texturing light beam;

the welding beam separation assembly (4) comprises a frequency doubling crystal (4.1) and a welding beam focusing mirror (4.2), and the separated third beam of light sequentially irradiates the frequency doubling crystal (4.1) and the welding beam focusing mirror (4.2) to obtain a welding beam.

6. The light-splitting device according to claim 5, wherein: the rotating speed of the cleaning beam galvanometer (2.2) with the rotating motor is less than or equal to 100000 times/s; the rotating speed of the textured light beam galvanometer (3.2) with the rotating motor is 20000-30000 times/s.

7. The light-splitting device according to claim 5, wherein: the cleaning beam reflecting mirror (2.1), the cleaning beam vibrating mirror (2.2) with the rotating motor, the texturing beam reflecting mirror (3.1) and the texturing beam vibrating mirror (3.2) with the rotating motor are all made of silicon dioxide with metal coating.

8. The light-splitting device according to claim 5, wherein: the cleaning beam focusing mirror (2.3), the texturing beam focusing mirror (3.3) and the welding beam focusing mirror (4.2) are all made of gallium arsenide.

9. The light-splitting device according to claim 5, wherein: the cleaning light beam focusing mirror (2.3), the texturing light beam focusing mirror (3.3) and the welding light beam focusing mirror (4.2) can be adjusted in position in the welding head shell (1), and the adjustment range is-10 mm.

10. A laser welding apparatus comprising the light splitting apparatus as recited in any one of claims 4 to 9.

Technical Field

The invention belongs to the field of laser welding, and particularly relates to a method and a device for multi-beam laser welding of nano modified aluminum alloy.

Background

Lightweight structural design is the important development direction of trades such as high-speed railway train, aerospace craft, shipbuilding, and lightweight structural design can promote payload by a wide margin, reduces energy consumption.

At present, in the field of lightweight structure design, the attempt to select other materials to replace steel materials is a trend, and meanwhile, how to realize high-quality and high-efficiency welding between materials is a problem which is widely concerned in the industry and academia; the aluminum alloy has higher specific strength and elastic modulus, so that the aluminum alloy is applied in a large area in lightweight structural design, and the structural weight can be reduced by more than 50% by adopting the aluminum alloy to replace steel materials. In addition, compared with a carbon fiber light composite material, the aluminum alloy is more convenient to produce and maintain. Therefore, how to achieve high-quality and high-efficiency welding of aluminum alloy is a problem of great concern in the industry and academia.

However, the existing laser welding aluminum alloy has the following difficulties: the aluminum alloy surface has high reflectivity, so that the laser energy utilization rate is low, and even the optical fiber and the laser can be burnt; al with high melting point is easily generated on the surface of the aluminum alloy₂O₃A film, resulting in deterioration of welding stability and causing defects such as hydrogen holes, inclusions, etc. in the weld. Therefore, the surface of the aluminum alloy needs to be pretreated before laser welding, and different from the traditional arc welding, plasma arc welding or laser welding of materials such as steel, titanium alloy and the like, the laser welding of the aluminum alloy has more special requirements on the pretreatment before the welding, and the oxide film on the surface is removed and the reflectivity of the surface to laser is reduced.

At present, most of the methods for surface pretreatment of aluminum alloy are limited to single purpose or single function, such as laser cleaning method, which can only be used for removing surface oxide film, and laser texturing method, which can only be used for reducing the reflectivity of the surface to laser. Due to the particularity of surface pretreatment before laser welding of the aluminum alloy, the requirement for singly removing the surface oxide film or reducing the surface reflectivity cannot be met, and good welding quality is difficult to obtain. In the prior art, a surface pretreatment technology which combines two treatment methods and has diversified and combined functions is not available.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method and a device for multi-beam laser welding of nano modified aluminum alloy. The invention forms multi-path synchronously loaded light beams by a light beam frequency conversion and light path design method, and sequentially performs laser cleaning, laser texturing and laser welding to complete integrated welding, can simultaneously solve the two problems of high laser reflectivity of the surface of a workpiece to be welded and difficulty in removing an oxide film on the surface, can obviously improve the forming quality and efficiency of a welding seam of the workpiece to be welded, and has no limitation of welding time.

In order to achieve the purpose, the invention designs a method for multi-beam laser welding of nano modified aluminum alloy, which comprises the following steps:

the light beam is divided into a cleaning light beam, a texturing light beam and a welding light beam in sequence along the welding direction by a light splitting device;

the workpiece to be welded sequentially enters a laser cleaning area, a laser texturing area and a laser welding area to be integrally welded; wherein the content of the first and second substances,

when the workpiece to be welded enters a laser cleaning area, cleaning the surface of the workpiece to be welded by a cleaning beam (impurities are oil stains, water and the like which are well known by a person skilled in the art, and the cleaning is to inhibit the generation of defects such as air holes, cracks and the like);

when the workpiece to be welded enters the laser texturing area, the texturing light beam increases the roughness of the surface of the workpiece to be welded after cleaning (in order to increase the absorptivity of the material to laser, further inhibit the high-reflection phenomenon and improve the forming quality of a welding seam);

and when the workpiece to be welded enters the laser welding area, welding the workpiece to be welded by the welding beam.

Further, in the step 1), the power of the cleaning beam is 10-60W, the swing amplitude of the cleaning beam is-10 mm, the scanning speed of the cleaning beam is 500-2000 mm/s, and the repetition frequency of the cleaning beam is 80-100 kHz;

the power of the textured light beam is 80-200W, the swing amplitude of the textured light beam is-5 mm, the scanning speed of the textured light beam is 6000-8000 mm/s, and the repetition frequency of the textured light beam is 10-20 kHz;

the power of the welding beam is 0-10000W, and the wavelength of the welding beam is 532 nm.

Still further, the workpiece to be welded is any one of an aluminum alloy workpiece, an aluminum magnesium alloy workpiece and a titanium alloy workpiece.

The invention also provides a light splitting device which comprises a welding head shell, wherein the top of the welding head shell is provided with an optical fiber pipeline, and a cleaning light beam separating assembly, a texturing light beam separating assembly and a welding light beam separating assembly are sequentially arranged on a line, entering the welding head shell, of light beams released by the optical fiber pipeline.

Furthermore, the cleaning beam separation assembly comprises a cleaning beam reflecting mirror, a cleaning beam vibrating mirror with a rotating motor and a cleaning beam focusing mirror, and the separated first beam of light beam sequentially irradiates the cleaning beam reflecting mirror, the cleaning beam vibrating mirror and the cleaning beam focusing mirror to obtain a cleaning beam;

the second light beam is separated and sequentially emitted to the texturing light beam reflecting mirror, the texturing light beam vibrating mirror and the texturing light beam focusing mirror to obtain a texturing light beam;

the welding beam separation assembly comprises a frequency doubling crystal and a welding beam focusing mirror, and the separated third beam of light is sequentially emitted to the frequency doubling crystal and the welding beam focusing mirror to obtain a welding beam.

Furthermore, the rotating speed of the cleaning beam galvanometer with the rotating motor is less than or equal to 100000 times/s;

the rotating speed of the textured light beam galvanometer with the rotating motor is 20000-30000 times/s.

And furthermore, the cleaning beam reflecting mirror, the cleaning beam vibrating mirror with the rotating motor, the texturing beam reflecting mirror and the texturing beam vibrating mirror with the rotating motor are all made of silicon dioxide with metal coating.

And furthermore, the cleaning beam focusing lens, the texturing beam focusing lens and the welding beam focusing lens are made of gallium arsenide.

And furthermore, the cleaning beam focusing lens, the texturing beam focusing lens and the welding beam focusing lens can be adjusted in position (adjusted to change the welding beam focusing position) in the welding head shell, and the adjustment range is-10 mm.

The invention also provides a laser welding device which comprises the light splitting device.

Components and action of light beams according to the invention

1. The cleaning beam is used for cleaning an oxide film and other impurities on the surface of the workpiece to be welded, so that the generation of defects such as air holes and cracks is inhibited;

2. the roughened beam is used for improving the roughness of the surface of the workpiece to be welded after cleaning, and increasing the absorption rate of the material to laser, so that the high-reflection phenomenon is inhibited, and the weld forming quality is improved.

The integrated cleaning, texturing and welding of the workpieces to be welded are realized by synchronously loading the light beams.

3. The cleaning beam reflector is mainly used for separating a cleaning beam (with power of 10-60W) from the main beam;

4. the cleaning beam galvanometer 2.2 with the rotating motor is mainly used for controlling the swing amplitude (+/-5 mm), the scanning speed (500-2000 mm/s) and the repetition frequency (70-140 kHz) of the cleaning beam, so that the dirt on the surface of the workpiece to be welded is effectively removed;

5. the textured light beam reflecting mirror is mainly used for separating a textured light beam (with the power of 80-200W) from the main light beam;

6. the texturing beam galvanometer with the rotating motor is mainly used for controlling the swing amplitude (+/-5 mm), the scanning speed (6000-8000 mm/s) and the repetition frequency (10-20 kHz) of a texturing beam, so that the effective texturing of the cleaning surface is realized;

7. the cleaning light beam focusing mirror can move up and down to adjust the focusing position of the cleaning light beam (the adjustable amplitude is +/-10 mm);

8. the texturing light beam focusing lens can also move up and down to adjust the focusing position of the texturing light beam (the adjustable amplitude is +/-10 mm);

9. the frequency doubling crystal converts the wavelength of a welding beam (with the power of 0-10000W) from 1068nm to 532nm, so that the absorption rate of a workpiece to be welded on the beam is improved;

10. the welding beam focusing mirror can move up and down to adjust the focusing position of the welding beam (the adjustable amplitude is +/-10 mm).

The invention has the beneficial effects that:

aiming at the defects that the existing three processes of laser cleaning, laser texturing and laser welding are separately implemented, the invention firstly uses the light splitting device to simultaneously split the same light beam into a cleaning light beam, a texturing light beam and a welding light beam; meanwhile, working parameters of the three beams of light beams are adjusted through components in the light splitting device, so that the working parameters meet working requirements to realize integrated integration, and after the workpiece to be welded is treated by the cleaning light beams, the cleanliness of the surface of the workpiece to be welded and the absorption rate of the workpiece to be welded to laser are improved; then, after the workpiece to be welded is subjected to texturing beam treatment, the absorption rate of the material to laser is increased, so that the high-reflection phenomenon is inhibited, and the weld joint forming quality is improved; and finally, welding greatly reduces the time required by welding pretreatment, and obviously improves the laser welding efficiency of the workpieces to be welded.

In conclusion, the invention integrally realizes the surface pretreatment and the laser welding of the workpieces to be welded, greatly improves the welding efficiency and quality, provides a simple and practical new method for ensuring the laser welding shape of the workpieces to be welded, and can adapt to the actual requirements of industrial production.

Drawings

FIG. 1 is a schematic view of an apparatus for a method of multi-beam laser welding a nano-modified aluminum alloy;

FIG. 2 is a schematic illustration of a laser welding process of a nano-modified aluminum alloy workpiece;

FIG. 3 is a top view of a laser welding process of a nano-modified aluminum alloy workpiece.

In the figure, a welding head shell 1, an optical fiber pipeline 1.1, a cleaning beam separation component 2, a cleaning beam reflector 2.1, a cleaning beam vibrating mirror 2.2 with a rotating motor, a cleaning beam focusing mirror 2.3, a texturing beam separation component 3, a texturing beam reflector 3.1, a texturing beam vibrating mirror 3.2 with a rotating motor, a texturing beam focusing mirror 3.3, a welding beam separation component 4, a frequency doubling crystal 4.1 and a welding beam focusing mirror 4.2 are arranged; the method comprises the following steps of a nano modified aluminum alloy workpiece 5 in an original surface state, a to-be-welded abutted seam 6, a laser cleaning area 7, a laser texturing area 8, a laser welding keyhole 9, a laser welding pool 10 and a solidified welding seam 11.

Detailed Description

The present invention is described in further detail below with reference to specific examples so as to be understood by those skilled in the art.

Example 1

A method for laser welding nanometer modified aluminum alloy by multiple beams comprises the following steps:

1) placing a nano modified aluminum alloy workpiece 5 in an original surface state containing a to-be-welded abutted seam 6 below a light splitting device, and sequentially dividing a light beam into a cleaning light beam, a texturing light beam and a welding light beam from front to back along a welding direction through the light splitting device; wherein the power of the cleaning beam is 10-60W, the swing amplitude of the cleaning beam is +/-10 mm, the scanning speed of the cleaning beam is 500-2000 mm/s, and the repetition frequency of the cleaning beam is 80-100 kHz;

the power of the texturing light beam is 80-200W, the swing amplitude of the texturing light beam is +/-5 mm, the scanning speed of the texturing light beam is 6000-8000 mm/s, and the repetition frequency of the texturing light beam is 10-20 kHz.

The power of the welding beam is 0-10000W, and the wavelength of the welding beam is 532 nm;

2) the nanometer modified aluminum alloy workpiece 5 with the original surface state to be welded sequentially enters a laser cleaning area 7, a laser texturing area 8 and a laser welding area to be integrally welded; wherein the content of the first and second substances,

when the nano modified aluminum alloy workpiece 5 enters the laser cleaning area 7, cleaning beams clean an oxide film and impurities on the surface of the nano modified aluminum alloy workpiece 5;

when the nano modified aluminum alloy workpiece 5 enters the laser texturing area 8, the texturing light beam increases the roughness of the surface of the cleaned nano modified aluminum alloy workpiece 5;

when the nanometer modified aluminum alloy workpiece 5 enters a laser welding area, a laser beam acts on the surface of the nanometer modified aluminum alloy workpiece 5 to form a keyhole 9, a material is melted through the action of heat to form a molten pool 10, the keyhole and the molten pool move forward continuously along with the progress of the welding process, and when the temperature of the rear part of the molten pool is lower than the liquid-solid transition temperature, the rear part of the molten pool is solidified to form a welding seam 11; completing the welding (as shown in figures 2-3).

Example 2

The light splitting device shown in fig. 1 comprises a welding head shell 1, wherein an optical fiber pipeline 1.1 is arranged at the top of the welding head shell 1, and a cleaning light beam separation assembly 2, a roughening light beam separation assembly 3 and a welding light beam separation assembly 4 are sequentially arranged on a line, entering the welding head shell 1, of a light beam released by the optical fiber pipeline 1.1; the cleaning beam separation component 2 comprises a cleaning beam reflector 2.1, a cleaning beam vibrating mirror 2.2 with a rotating motor and a cleaning beam focusing mirror 2.3, wherein the separated first beam of light beam sequentially irradiates the cleaning beam reflector 2.1, the cleaning beam vibrating mirror 2.2 and the cleaning beam focusing mirror 2.3 to obtain a cleaning beam;

the frosted light beam separation component 3 comprises a frosted light beam reflecting mirror 3.1, a frosted light beam vibrating mirror 3.2 with a rotating motor and a frosted light beam focusing mirror 3.3; the separated second light beam is sequentially emitted to a texturing light beam reflecting mirror 3.1, a texturing light beam vibrating mirror 3.2 and a texturing light beam focusing mirror 3.3 to obtain a texturing light beam;

the welding beam separation component 4 comprises a frequency doubling crystal 4.1 and a welding beam focusing mirror 4.2, and the separated third beam of light sequentially irradiates the frequency doubling crystal 4.1 and the welding beam focusing mirror 4.2 to obtain a welding beam.

The rotating speed of the cleaning beam galvanometer 2.2 with the rotating motor is less than or equal to 100000 times/s.

The rotating speed of the frosted beam galvanometer 3.2 with the rotating motor is 20000-30000 times/s.

The cleaning beam reflecting mirror 2.1, the cleaning beam vibrating mirror 2.2 with the rotating motor, the texturing beam reflecting mirror 3.1 and the texturing beam vibrating mirror 3.2 with the rotating motor are all made of silicon dioxide with metal coating.

The cleaning beam focusing mirror 2.3, the texturing beam focusing mirror 3.3 and the welding beam focusing mirror 4.2 are made of gallium arsenide.

The cleaning beam focusing mirror 2.3, the texturing beam focusing mirror 3.3 and the welding beam focusing mirror 4.2 can be adjusted up and down on the welding head shell 1, and the adjustment ranges of the cleaning beam focusing mirror, the texturing beam focusing mirror and the welding beam focusing mirror are +/-10 mm.

The process of the light splitting device comprises the following steps:

the light beam generates three light beams, namely a cleaning light beam, a texturing light beam and a welding light beam through a light splitting device;

the nanometer modified aluminum alloy workpiece 5 with the original surface state to be welded sequentially enters a laser cleaning area 7, a laser texturing area 8 and a laser welding area to be integrally welded; wherein the content of the first and second substances,

when the nano modified aluminum alloy workpiece 5 enters the laser cleaning area 7, cleaning beams clean an oxide film and impurities on the surface of the nano modified aluminum alloy workpiece 5;

when the nano modified aluminum alloy workpiece 5 enters the laser texturing area 8, the texturing light beam increases the roughness of the surface of the cleaned nano modified aluminum alloy workpiece 5;

when the nanometer modified aluminum alloy workpiece 5 enters a laser welding area, a laser beam acts on the surface of the nanometer modified aluminum alloy workpiece 5 to form a keyhole 9, a material is melted through the action of heat to form a molten pool 10, the keyhole and the molten pool move forward continuously along with the progress of the welding process, and when the temperature of the rear part of the molten pool is lower than the liquid-solid transition temperature, the rear part of the molten pool is solidified to form a welding seam 11; and integrated and automatic welding is realized.

Example 3

A laser welding device comprises the light splitting device.

The laser welding device comprises the following processes:

when the nanometer modified aluminum alloy workpiece 5 enters a laser welding device, the light beam generates three light beams which are respectively a cleaning light beam, a texturing light beam and a welding light beam through a light splitting device;

the nanometer modified aluminum alloy workpiece 5 with the original surface state to be welded sequentially enters a laser cleaning area 7, a laser texturing area 8 and a laser welding area to be integrally welded; wherein the content of the first and second substances,

when the nano modified aluminum alloy workpiece 5 enters the laser cleaning area 7, cleaning beams clean an oxide film and impurities on the surface of the nano modified aluminum alloy workpiece 5;

when the nano modified aluminum alloy workpiece 5 enters the laser texturing area 8, the texturing light beam increases the roughness of the surface of the cleaned nano modified aluminum alloy workpiece 5;

when the nanometer modified aluminum alloy workpiece 5 enters a laser welding area, a laser beam acts on the surface of the nanometer modified aluminum alloy workpiece 5 to form a keyhole 9, a material is melted through the action of heat to form a molten pool 10, the keyhole and the molten pool move forward continuously along with the progress of the welding process, and when the temperature of the rear part of the molten pool is lower than the liquid-solid transition temperature, the rear part of the molten pool is solidified to form a welding seam 11; and (5) completing welding.

Other parts not described in detail are prior art. Although the present invention has been described in detail with reference to the above embodiments, it is only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and the embodiments are within the scope of the present invention.