Laser nitriding and ion beam analysis

Laser nitriding of metals has become an interesting process for industrial applications since it can improve the hardness and the wear and corrosion properties of tools and functional pieces. In the present case, the irradiation of pure iron and steel with short pulses of an excimer laser in pure nitrogen gas led to nitrogen concentrations of more than 30 at.% in the treated surfaces. Ion Beam Analysis has proven to be a powerful tool in analyzing these laser nitrided surfaces. Rutherford Backscattering Spectrometry and nitrogen analysis via the resonant nuclear reaction {sup 15}N(p,{alpha}{gamma}){sup 12}C provides accurate lateral and depth profiles of the nitrogen in the laser treated samples. The further potential of this method was exploited by carrying out laser treatments in alternating, isotopically enriched nitrogen atmospheres ({sup 15}N/{sup 14}N). Due to the exclusive sensitivity of the method to {sup 15}N, it has been possible to reveal the competition of new nitrogen take-up with the lateral material transport and fall-out generation.