In the aircraft industry, which has a large number of connections of various designs previously made by riveting, aluminum alloys are frequently used. Mounting defects include the additional weight of the structure, stress concentration, crevice corrosion, and vibration-induced collapse. In addition, it is a labor and time-intensive job. The laser welding can be used. A future tool that, because of its heat, is preferred over other joining methods, such as arc welding. Filling type and its effect on the microstructure. The work aims to develop the laser welding process to obtain the best mechanical properties close to the original metal's properties, where modern methods are used and bypass the old traditional methods. Through a mathematical model (BBD), it is proposed to develop the process used depending on several variables used in welding aluminium alloy sheets (6061-T6), such as the effect of welding speed, smoothness, and shielding gas flow rate (He, without shielding gas) Minimum welds and surface defects. A study of the weldability of the alloy in terms of joint strength, toughness and fatigue was performed. The weld current was also investigated by comparing the hardness and tensile test results. The design software and fatigue testing were used to determine and then generate ideal process parameters by generating a mathematical model. Helium provided the best result compared to other shielding gas conditions used in the investigation, and laser-material interaction was possible. Flawless microstructures, welds and hardness data confirmed a heat-affected zone (HAZ) and a 10% decrease in total hardness after welding. A decrease in the bending resistance was observed by 6.9%. And a decrease in the fatigue test by about 35%. These values are the best that can be obtained, and they are closer to the mechanical properties of the metal before the welding process. © 2024 American Institute of Physics Inc.. All rights reserved.