Study on the Characteristics and Mechanics of Droplet Transfer in Laser Arc Hybrid Welding Process

doi:10.3901/JME.2018.06.154

Abstract

Abstract: The droplet transfer, plasma morphology and droplet morphology of laser arc hybrid welding process are collected and analyzed using high speed camera. The force magnitude and acceleration of motion droplets in the arc space are calculated by the image processing and mathematical calculations. The value and distribution of the recoil force from the metal vapor on droplets are calculated. The results show that the mode of globular transfer corresponds to the welding current is approximately 180A; the mode of streaming transfer corresponds to the welding current is approximately 200 A. The laser has a compress effect on the arc, and the compression on the surface of the weld pool is stronger. The acceleration of the droplet detachment from wire for arc welding and laser arc hybrid welding is 70 m/s² and 50 m/s² separately. In the actual welding process, the reaction force of metal vapor on molten droplets is very small, when the distance between droplet and keyhole in the surface of the weld pool is 3 mm. The laser changes the shape arc, and the pressure difference between upper and lower surface of the droplet is changed, which results when the droplet is close to the surface of the weld pool, the droplet coalescence and the transition frequency are slowed down.

Key words: high nitrogen steel, laser-arc hybrid welding, mechanics analysis, metal droplet

CLC Number:

TG456

XU Chunying, LIU Shuangyu, ZHANG Hong, LI Yanqing, LIU Fengde. Study on the Characteristics and Mechanics of Droplet Transfer in Laser Arc Hybrid Welding Process[J]. Journal of Mechanical Engineering, 2018, 54(6): 154-161.

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