Study on Fiber Laser Welding of AA6061-T6 Samples through Numerical Simulation and Experiments

A three-dimensional finite element model based on thermo-elastic-plastic model is applied to simulate the temperature and residual stress of aluminum alloy joint weld during fiber laser welding. Transient temperature, residual stress field, and joint distribution are studied, and the influence of laser power influence and welding speed is analyzed. A laser welding system can automatically preheat and weld in the seal cavity full of nitrogen. The laser welding system welds 2 mm thick 6061-T6 joints with processing parameters determined by simulation. The appearance of the weld bead of the joint is smooth and continuous. The welded joint specimens can be used for low-cycle tensile-tensile fatigue tests. The fracture of fatigue test is located in the HAZ of the welded joint. Result provides support for research and technology optimization of fiber laser welding.