Correlation of internal and surface temperatures during laser cutting of epoxy-based carbon fibre reinforced plastics

Abstract

A strong criterion in the evaluation of laser-cut carbon fibre reinforced plastics is the thermal damage of the material. The visible heat affected zone is used as an indicator for the deterioration, which can be measured by destructive methods only. For the purposes of this paper, a non-destructive and contactless heat affected zone estimation method was developed based on experimental data. For this purpose, the internal and surface temperatures were measured simultaneously in order to gain a better understanding of the temperature distribution during laser cutting. Thermocouples and a thermography camera were used for the measurement of the internal and surface temperature, respectively. Based on the data, the internal and surface temperatures were initially correlated. Furthermore, the dependency of the measured surface temperature with the distance between measuring point and heat affected zone was plotted. For the present material and process, this information can be used to estimate the heat affected zone in real-time without the need of destructive testing.