Alternating current magnetic field assisted laser deep penetration welding method for reducing aluminum alloy weld pores

Abstract

The invention discloses an alternating current magnetic field assisted laser deep penetration welding method for reducing aluminum alloy weld pores. The method is characterized in that after the bottom of the butt joint part of a to-be-welded sample is suspended, an alternating current electromagnetic field is preset below the to-be-welded sample, and a laser welding work head above the sample andthe alternating current electromagnetic field below the sample are kept still in the laser welding process; and the laser beam is focused on the upper surface of the aluminum alloy, and the magneticfield action range always covers the whole molten pool area until laser deep penetration welding is completed. According to the method, the weld porosity is reduced to the maximum extent while the weld penetration is kept unchanged, namely, the weld bearing area is increased. In addition, irregular fluctuation of the surface of an original weld joint due to the existence of pores is also inhibited, and the improvement of surface forming is also beneficial to the improvement of the joint strength.

Description

technical field [0001] The invention relates to a technology in the field of laser welding, in particular to an AC magnetic field-assisted laser deep penetration welding method for reducing pores in aluminum alloy welds. Background technique [0002] At present, submerged arc welding and gas metal shielded welding are mainly used for the connection of medium and thick aluminum alloys of large structural parts in the fields of ships, pipelines, and wind energy equipment. However, these technologies have low welding efficiency and large heat input. Easy to produce large deformation. As a flexible welding method that can be automated, laser welding has the advantages of high energy density, good flexibility and small deformation, and is an excellent choice for welding medium and thick plates. [0003] During the laser deep penetration welding process, the material at the laser incident position evaporates violently, and the recoil pressure of the metal vapor squeezes the molte...

AI Technical Summary

Problems solved by technology

For laser deep penetration welding of aluminum alloys with low surface tension and viscosity, the problem of small hole pores is more serious, resulting in technical problems of reduced joint strength. An AC magnetic field assisted laser deep penetration welding method to reduce weld pores in aluminum alloys is proposed. , on the premise of maintaining a large penetration depth, there is no need to preheat before welding or change the welding process parameters to suppress the porosity, just adjust the appropriate magnetic field parameters to avoid excessive magnetic field disturbances from aggravating the instability of welding small holes, using alternating The Lorentz force generated by the magnetic field in the molten pool drives the bubbles upward to escape, so as to suppress or even completely eliminate the small pores

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