Measurement of temperature-dependent reflectivity of Cu and Al in the range 30-1000 degrees C

In the CO₂ laser cutting process it is important to predict the absorption mechanism during laser-workpiece interaction, since the form of the dependence of absorption on temperature greatly affects the form of the resulting temperature profile in the material. In order to be able to use any of the theoretical models for absorption with any degree of confidence, it appears necessary to obtain experimental data on the subject. Consequently an experiment to determine the variation of absorption with temperature is necessary. A reflectivity method is employed to measure the temperature- dependent reflection coefficient experimentally. The results obtained from the experiment for aluminium and copper samples are then compared with the theoretical results. In the analysis, high-temperature surface oxidation is also included.