Experiment and prediction of weld morphology for laser oscillating welding of AA6061 aluminium alloy

ABSTRACT

Effects of oscillating diameter (D) and frequency (f) on weld surface and cross-sectional morphologies were investigated in laser welding of AA6061 aluminium alloy with circular beam oscillation. Weld surface was mainly characterised by straight line shape when f > 10 Hz. Weld cross-section transformed from slender nail to irregular shape, dumpy nail, rectangle and crescent shape in sequence with the increase of D and f. A modified model considering material thermal properties was developed to predict the surface feature, especially whether the weld totally overlapped or not. A new normalised enthalpy was proposed to predict the keyhole mode of laser oscillating welding by considering materials thermal properties and remelting effect, which was suitable to explain the formation of cross-sectional morphology.

KEYWORDS:

• Laser welding
• aluminum
• beam oscillation
• morphology
• prediction

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research is financially supported by the National Natural Science Foundation of China (Grant nos. 51275186, 51475183 and 51775206).