Analysis of laser welding process and porosity suppression based on controllable adjustment of energy and distribution

Unlike traditional continuous and pulsed lasers, in this study, the laser fixed-point and fixed-energy modulation of the molten pool is controlled by varying different energy elements. It can be obtained that the heat input is effectively reduced, the weld penetration is increased, and the porosity can be effectively reduced by 12.56% with the same value of total energy. By regulating different energy elements at the same location, the overall average temperature can be reduced, the molten depth can be increased, and the porosity can be decreased. Using a combination of large and small cyclic energies for regulation can effectively reduce heat input, achieving an overall maximum temperature reduction of 22.47 ℃. The most significant increase in molten depth was 13.21 µm at the three energies of 900W, 870W, and 840W combinations, and the porosity was reduced by 12.77%. By precisely controlling energy and distribution, the melt depth at each energy point can be greater than the reference value, and the porosity can be reduced across the entire range. The combination of 870w, 540w, and 330w is the optimal parameter set, which not only has the lowest porosity but also has a relatively large penetration depth. The experimental results indicate that by adjusting the size of different energy elements at various point distributions, and by regulating each point, line, and area in the weld seam, the heat input to the molten pool can be controlled. This results in welds that are aesthetically pleasing, have enhanced penetration, and exhibit low porosity.