Absorption dynamic behaviour of metals during CO2 laser solid state treatments

In order to control CO2 laser treatments, precise knowledge of the CO2 radiation-surface coupling is required. For this purpose, a numerical identification of the absorption coefficient was achieved from thermal cycles measurements and computations. Variations of the coupling during the laser treatment were studied both in the case of the hardening of pre-coated steel (XC 55: 0.55% C, 0.18% Cr with graphite and manganese phosphate coatings) and in the case of the solid state nitriding of titanium alloys (TA6V).