Process parameter selection for laser welding of aluminium alloy from the perspective of energy effectiveness

Laser welding is an indispensable part of competitive manufacturing, but it has a critical issue with energy consumption. The existing literature is limited to the energy supplied to the laser-material interaction for the material welding, and the welding quality is not well considered for energy saving. To reduce the total energy consumption of laser welding without compromising the welding quality, this study investigates the effects of process parameters including the laser power, welding speed and focus position on the specific energy consumption (SEC), welding quality and related energy effectiveness (EE) of the laser welding of 6061 aluminium alloy. The results reveal that adjusting the laser power to improve the welding quality will inevitably lead to a significant increase in the SEC. Energy can be saved with a relatively stable welding quality by varying the welding speed, and the welding quality can be improved without appreciably increasing the energy consumption by setting the focus position to approximately -0.5 mm. The EE can be enhanced with a higher laser power within a moderate welding speed range at the negative focus position. A case demonstrated that with a reasonable process parameter configuration, an energy savings of 12.45% could be realised for laser welding, while the tensile strength was increased by 4.29%, and the weld bead integrity remained stable (a decrease of 0.11%).