Sequential laser pulse thermal excitation method for the detection of defects in metallic materials

This paper mainly explores the application of thermal signals generated by sequential laser pulses in the detection of metal material defects. Here we use flat bottom holes with different sizes on stainless steel as our sample. Sequential laser pulses are used as thermal excitation source and the surface temperature field is recorded by infrared thermal imager.By analyzing the relationship between the surface temperature of the defect area under sequential pulse excitation, the defect aspect ratio can be obtained due to different 3D thermal diffusion process. The experimental scheme and data processing method described in this paper provide a new method and theoretical basis for the measurement of metal defects size by sequential laser pulses, and have certain reference value for the detection and research of other metal material defects