Laser welding of Al6061 alloy with dynamic beam shape

Modern laser systems can greatly enhance the technological capabilities of welding processes. This paper examines the laser welding of the Aluminum 6061 alloy using a 14 kW fiber laser equipped with Optical Phase Array (OPA) technology, which allows for dynamic beam shaping at frequencies ranging from 1 to several hundred kHz. The study investigates different beam shape oscillation frequencies to identify optimal conditions that reduce welding defects. The “line” shape performed exceptionally well, achieving defect-free welds at a speed of 190 mm/s. Microstructural analysis of the weld/HAZ zone, which included optical microscopy and SEM/EBSD, revealed refined grains with morphological and crystallographic texture decreasing with increasing laser scan speed. The microstructural evaluation was conducted according to ISO 13919-2 and AWS D1.2 standards. The tensile strength reached 70-80% of the base material without the use of filler due to reduced defects and optimized energy distribution. These findings underscore the potential of the dynamic beam shape for producing high-quality welds in Aluminum 6061 for structural applications.