Physical laws governing the interaction of pulse-periodic CO2 laser radiation with metals

It is shown theoretically and experimentally that the efficiency of welding metals with a pulse-periodic CO₂ laser beam of low duty ratio, at low velocities, can exceed that of welding with cw lasers and with electron beams. For the first time an investigation was made of the influence of the laser radiation parameters (energy and frequency) and of the welding velocity on the characteristics of the weld and on the shape of the weldpool. The influence of the laser radiation polarization on the efficiency of deep penetration was analyzed.