Reactive surface processing by irradiation with excimer laser, Nd : YAG laser, free electron laser and Ti : sapphire laser in nitrogen atmosphere

Abstract

Surface coatings and thin films can be easily produced by irradiation of materials with short laser pulses in (reactive) gas atmospheres, e.g. nitrided iron and steel or AlN films on Al and its alloys by irradiation with an excimer laser in nitrogen atmosphere. For these treatments, various lasers with different wavelengths and time structures can be used. In addition to the experiments with excimer laser (pulse duration: 55 ns; wavelength: 308 nm), also the results of irradiations with Nd:YAG laser (pulse duration: 8 ns; wavelength: 1060 nm), free electron laser (FEL) (pulse duration: 2 ps; wavelength: 3 mum) and Ti:sapphire laser (pulse duration: 150 fs; wavelength: 750 nm) will be presented. The pulse duration varies from nanoseconds to femtoseconds and thus includes different laser interaction regimes. The results of the surface modifications and coating formation for the irradiation of different types of materials (Fe, Al, Si, and Ti) in pure nitrogen atmosphere will be presented. (C) 2002 Elsevier Science B.V. All rights reserved.