Numerical study of beam oscillation and its effect on the solidification parameters and grain morphology in remote laser welding of high-strength aluminium alloys

This study investigated the effect of beam oscillation on the solidification behaviour during laser welding of Al-5754 to Al-6061 alloy. In this study, a finite element model has been developed to simulate temperature and fluid flow fields by implementing different combinations of volumetric heat source models. Solidification parameters such as temperature gradient (G), solidification rate (R), cooling rate (G x R) and G/R are evaluated to understand the mechanism of microstructure formation. It was found that beam oscillation improves the tensile strength by 21.4% for full penetration welding due to an increase in the percentage of formation of equiaxed grains. Modelling results revealed that the cooling rate increases with an increase in oscillation frequency. However, tensile strength followed a parabolic distribution with a peak at the oscillation frequency of 300 Hz.

Automated summary

This study investigated how beam oscillation affects the solidification behavior during the laser welding of Al-5754 to Al-6061 alloy. They developed a finite element model to simulate temperature and fluid flow fields using different volumetric heat source models. Various solidification parameters were evaluated to understand microstructure formation. The results showed that beam oscillation improved tensile strength by 21.4% due to an increase in equiaxed grain formation. Modeling also revealed that cooling rate increased with oscillation frequency, but tensile strength had a peak at 300 Hz.