Effect of oscillation parameters on adjustable-ring mode (ARM) laser beam welding of aluminum alloys

This study investigates the effects of oscillation amplitudes and frequencies on the surface quality, macro- and micro-structure, and porosity in adjustable-ring mode (ARM) laser oscillation welding of A5083 aluminum alloy plates. Results show the weld surface quality is improved with the increase of oscillation amplitudes and frequencies. A transition of weld cross section from a "goblet" shape to a "crescent" shape is observed as the amplitude increases. Microstructure analysis reveals the grain size in the weld does not decrease with the increase of oscillation amplitudes and frequencies because of the competition between stirring effect and cooling rate reduction. The porosity of the weld seam decreases with increasing oscillation parameters, with a final porosity of 0.22 % achieved at a 2 mm amplitude. Three-dimensional X-ray tomography further confirms the influence of oscillation on pore distribution: large pores tend to gather behind the molten pool rear wall, while small pores exhibit better symmetry. These findings provide valuable insights into optimizing oscillation parameters to achieve high-quality laser welds in A5083 aluminum alloy applications.