Influence of IR camera integration time on the accuracy of Tmax determination during laser interaction with ceramics

This paper presents the results of an infrared thermography (IRT) application for monitoring temperature distribution on a ceramic surface during Nd: YAG laser irradiation. The laser operated in the Q-switch mode with λ= 1064 nm. The duration of a pulse was τ = 8 ns. The repetition rate was f l = 1-20 Hz. FLIR, E40 and SC7200 IR cameras were used. Recording of the maximum temperature in the irradiated zones is very important information related to the damage threshold of materials. The tested sample is a piece of a ceramic tile. A large number of factors affect determination of the maximum temperature in the very fast processes as it is irradiation with laser pulse duration of 8 ns. One of them is the camera integration time. The experimental results have shown that IR cameras, even those with high performance such as SC7200, cannot record the maximum temperature value at the moment of laser operation, but only the average temperature of the bulk sample material after laser pulses. The microstructure and micromorphology of the ceramic surface after the laser treatment were analyzed by optical and scanning electron microscopy.