Investigation of weld formation and porosity in 5052 aluminium alloy laser-GMA hybrid welding assisted by magnetic field with different orientations

Abstract

Steady magnetic field with both orientations including longitudinal magnetic field (LMF) and transverse magnetic field (TMF) was used. The influence of LMF and TMF on weld formation, porosity and mechanical property of 5052 aluminium alloy laser-gas metal arc (GMA) hybrid welding was investigated. The shielding effect of hybrid plasmas on laser energy was weakened by TMF, leading to an increase in weld depth under TMF. Porosity rate was significantly reduced to 2.61% under TMF, because keyhole stability was improved, escaping channels for bubbles were increased, and solidification time of molten pool was prolonged. As a result, the highest tensile strength (174.7 MPa) of hybrid weld was obtained at TMF, owing to the lowest porosity rate.

Effect of beam oscillation frequency on porosity in laser welding of aluminum alloy lap-butt joints

“…Additionally, the duration for bubbles to escape also played a crucial role in porosity formation. 27 The oscillation of the laser beam influences the cooling and solidification of the molten pool, thereby altering the probability of bubble escape from the molten pool.…”