Influence of Longitudinal Laser Beam Oscillation on Hot Cracking and Stress Distribution in Laser-Welded Aluminum

This study analyzed the effect of longitudinal laser beam oscillation on the generation of hot cracking and stress distribution in Al 6061-T6. Experiments were conducted on Al 6061-T6 specimens with a thickness of 1.5 mm, comparing hot crack susceptibility and stress distribution according to oscillation amplitude and frequency. Observations of molten pool shape dynamics and hot crack characteristics, obtained via high-speed camera and X-ray equipment, concluded that low-frequency oscillation in the longitudinal direction (under 50 Hz) effectively suppressed crack formation. Additionally, laser welding simulations using Abaqus software revealed that the tensile stress around the fusion zone was influenced by the frequency and amplitude of the laser beam oscillation. This study demonstrated that optimizing the oscillation welding process could help reduce crack susceptibility and mitigate hot cracking.