Aluminium alloy laser welding method by powder reinforced absorption

Abstract

The present invention relates to powder absorption reinforced aluminum alloy laser welding method in laser material processing field. Into one common laser welding apparatus, one powder feeder is increased and has its powder feeding nozzle fixed to the laser welding head in the angle of 25-75 deg to the surface of workpiece. The present invention features that the fed aluminum or aluminum alloy powder of size 2-300 micron in the feeding speed of 1-20 g / min; and the laser power density of 0.15-3.5 MW / sq cm for CO2 laser welding and 0.1-1.8 MW / sq cm for YAG laser. Owing to the great specific surface area and small size effect of the powder, the metal or alloy powder under the action of the laser beam is gasified to form plasma, and this reinforces the absorption of the aluminum alloy material to laser, realizes the high efficiency laser welding at low power density of aluminum alloy material and reduces the requirement in laser power and laser beam quality for welding aluminum alloy.

Description

technical field [0001] The invention discloses an aluminum alloy laser welding method through powder enhanced absorption, which belongs to the technical field of laser material processing. Background technique [0002] With its good physical, chemical and mechanical properties, aluminum alloy can be widely used in aerospace, chemical industry, power electronics, light vehicle manufacturing and other fields. Laser welding has outstanding advantages such as small heating area, high energy density, fast welding speed, excellent joint performance, and small welding deformation. It is considered to be an advanced welding method that realizes the most technical and economic advantages of aluminum alloy structural connections. [0003] According to different welding mechanisms, laser welding is divided into heat conduction welding (power density is generally 10 4 W / cm 2 ~10 6 W / cm 2 between) and deep penetration welding (power density is generally 10 6 W / cm 2 ~10 7 W / cm 2 b...

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Problems solved by technology

[0008] In view of the high critical power density of existing aluminum alloy laser deep penetration welding, some high-power lasers cannot obtain the power required for aluminum alloy deep penetration welding due to poor beam quality, so that the laser welding of aluminum alloys and the welding process of aluminum alloy deep penetration welding cannot be performed. Difficult to control and other problems, the present invention proposes an aluminum alloy laser welding method through powder enhanced absorption, so that within the power density range of the general laser thermal conduction welding mode, high-efficiency welding of aluminum alloys can be realized, and the output of aluminum alloy laser welding on the laser can be reduced. Power and Beam Quality Requirements

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