Laser penetration fusion welding device assisted by cooperation of double magnetic fields and ultrasonic waves

Abstract

The invention provides a laser penetration fusion welding device assisted by cooperation of double magnetic fields and ultrasonic waves. The laser penetration fusion welding device comprises a base, a workbench, a mechanical arm, a laser welding machine, a moving mechanism, a welding table, an ultrasonic vibration machine, an alternating electromagnetic field coil, an alternating electromagnetic field power source, a constant electromagnetic field coil and a constant electromagnetic field power source. By utilizing the combined action of ultrasonic waves and the electromagnetic fields, escape of gas in a molten pool is accelerated, and the pore defect is inhibited; meanwhile, by means of the coupling effect of ultrasonic impact force and magnetic field electromagnetic force, intermetallic brittle compounds and coarse grains are broken, the number of the intermetallic brittle compounds is reduced, the grains are refined, and the welding quality is improved. A laser penetration fusion welding heat transfer and mass transfer mathematical model under the synergistic effect of a magnetic field and ultrasonic waves is established, the heat transfer and flowing rules of the molten pool in the welding process are revealed, the influence of the ultrasonic waves and an alternating magnetic field on the bubble floating rate and the influence of a stable magnetic field on the molten pool solidification rate are researched, and the mechanism of reducing the pore defect is mainly analyzed.

Description

technical field [0001] The invention relates to the technical field of laser welding, in particular to a laser deep penetration welding device assisted by dual magnetic fields and ultrasonic waves. Background technique [0002] Energy saving and consumption reduction and environmental pollution reduction have become common problems faced by human beings. Reducing the weight of transportation tools can effectively reduce fuel consumption and emissions, so more and more light metals (such as aluminum alloys, magnesium alloys, etc.) are used in vehicles, aerospace and other vehicles. Magnesium and aluminum are two widely distributed metal elements in the earth's crust, and their excellent properties have attracted more and more attention. Magnesium alloy has the advantages of light weight, high specific strength and specific stiffness, good shock resistance, radiation resistance, and easy recycling, and is known as the "green engineering material" in the new century. Similarl...

AI Technical Summary

Problems solved by technology

Due to the high melting point of oxides such as MgO and Al2O3, it is not easy to melt during the welding process, and it is easy to form inclusions, thereby reducing the strength of the welded joint; at the same time, The melting point and boiling point of magnesium and aluminum are relatively low. In the process of high-power welding, it is easy to cause evaporation or even burning of alloying elements, and it is easy to cause the weld to collapse, which in turn leads to a significant decrease in the strength of the welded joint.

[0005](2) Welding problems caused by coarse grains, thermal stress and cracks

In addition, the thermal expansion coefficient of magnesium and aluminum is relatively large, so it is easy to generate large welding stress during the welding process, and the temperature in the brittle range is wide, which is easy to form cracks, which in turn affects the mechanical properties of welded joints

[0006](3) Formation of brittle intermetallic compounds

Intermetallic brittle compounds are easily formed during welding of dissimilar metals such as magnesium and aluminum, and excessive intermetallic brittle compounds in the weld will seriously reduce its mechanical properties

[0007](4) Soldering problems due to solubility differences

In addition, because the stirring time of the single alternating magnetic field on the molten pool is very short, the effect on the refinement of the welded structure is not obvious

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