On line monitoring of pulsed-periodic Nd-yag laser welding by the pyrometers

摘要

Real-time temperature monitoring in pulsed-periodic laser welding gives a unique opportunity to analyse the dynamics of heat processes using various time-scales: on the one hand, precise monitoring of surface temperature during the action of individual laser pulse and the subsequent cooling stage; on the other hand, during the total duration of welding (i.e. the action of all the series of laser pulses). By temperature monitoring one may control the deviations from the required range of welding parameters : pulse energy and duration, pulse shape, welding speed, accuracy of laser beam position relatively the junction, etc. Trials have shown that the developed pyrometers could be used as sensors for process monitoring and on-line control.