Combustion of metals under the action of cw CO2 laser radiation

An experimental and theoretical study was made of laser-induced ignition and combustion of a number of metals in air. In the theoretical model account is taken of the oxidation of the metal, following a paralinear law, and of the variation in absorptivity of the oxide-metal system as the thickness of the oxide layer changes. Forced and self-supporting combustion regimes are considered. The physical features of metal ignition under the combined action of cw and pulsed laser radiation are explained. It is shown that interference phenomena in the oxide-metal layer system play an important part in the ignition process for tungsten. The results obtained are in good agreement with experiment.