Diagnostics of the process of formation of the welded joint in laser welding using a flat double probe

The use of the flat double electrode probe in laser welding is proposed for the diagnostics of welded joint formation. The diagnostics can be carried out in the plasma formed above the weld zone on the basis of the variation of the amplitude-frequency characteristics of the current in the probe circuit. The most accurate correlation of the amplitude of the probe current with the penetration depth was obtained in the frequency range of 30-100 Hz, with a correlation coefficient of 0.55-0.60. The results of the analysis of the amplitude-frequency characteristics were used for devising a structural diagram of an automatic system for controlling the penetration parameters in laser welding.