Coupling mechanism of laser and arcs of laser-twin-arc hybrid welding and its effect on welding process

Laser-twin-arc hybrid welding, which combines the techniques of laser welding and twin-arc welding, is an emerging welding technology. In this study, synchronous information including spectral signal, high-speed photography and electrical signal is used to explore the physical interaction between the arcs and the laser of alternate burning in laser-twin-arc hybrid welding process, and the effect of the combined arc/laser heat source on the welding process was analyzed. The results indicated that the laser provides a conductive, stable plasma channel for the arcs, which can influence the arc shape, slow down droplet transfer, reduce resistivity and stabilize arcs. Electron temperature of hybrid arc plasma is from 7000 K to 17000 K, which is significantly influenced by laser parameters. The laser-twin-arc hybrid welding acquires deeper penetration and wider HAZ than with the twin-arc welding alone.

► We study the coupling mechanism of laser and arcs during laser-twin-arc hybrid welding process.
► A particular phenomenon-alternate arcing is observed in single power support mode.
► Laser influences arc shape, droplet transfer, electron temperature and microstructure.
► Electron temperature of hybrid arc plasma is from 7000 K to 17000 K.
► Laser-twin-arc hybrid welding acquires deeper penetration and wider HAZ than twin-arc welding.