Laser welding efficiency and cost: CO₂, YAG, fiber, and disc

The welding performance of CO₂, YAG, fiber, and disc lasers was analysed from a steel welding efficiency perspective. Laser welding efficiency is defined here as melting rate per unit of delivered laser energy, mm³/kJ, although references to absolute, dimensionless welding efficiency are also included. Measured welding efficiencies (50-60 mm³/kJ) were found to be at or beyond the theoretical limits suggested by others, and no dramatic difference in welding efficiency was observed among the four lasers studies. The relative costs of laser operation in a high-volume production scenario were analyzed and included approximately 50 input values for each case. Laser operating costs and welding rates were combined to yield minimum possible specific welding costs ranging from 2.5 to 4 cents/cm³, including only laser and optics-related cost elements.