Effects Of Laser Irradiation To Metal/Explosive

In this thesis, the methods of experimental measurements and numerical simulation are employed to study the effects of laser irradiation to metal/explosive structure, including the energy coupling of steel surface to laser, the heat conduction in the structure and the ignition of the explosive.First, the temperature dependence of reflectivity of 45# steel at the wavelength of 1.319μm is measured using the integrating sphere system. By analyzing the surface energy spectrum of heated steel plates, a conclusion is obtained that the decrease of the reflectivity is mainly due to the oxidation of surface.Then, the irradiation effects of Q235 steel by 1.053μm pulse laser are investigated by measuring the reflectivity and the surface energy spectrum, analyzing the metallographic structure and calculating the temperature fields. The law of the change of energy coupling coefficient during the process of pulse laser irradiation has been obtained. It is shown that the increase of energy coupling coefficient is mainly due to the oxidation of surface.Finally, the temperature field in the metal/explosive structure irradiated by CW laser is calculated based on ANSYS. The result shows that the temperature rise of explosive becomes less evident as the thickness of metal increases. One-dimensional numerical model is presented to simulate the process of ignition of metal/explosive irradiated by laser. Ignition times, as functions of power density of laser and thickness of metal, are also obtained.