MOSSBAUER INVESTIGATION OF SURFACE PROCESSING BY PULSED LASER IRRADIATION IN REACTIVE ATMOSPHERES

摘要: Irradiations of iron (Armco, Fe > 99.85%) substrates in controlled gaseous atmospheres (nitrogen and methane) have been performed with nanosecond pulses an excimer laser, leading to the formation nitride carbide surface layers, respectively, different stoichiometry crystallographic structures. The evolution abundance each phase is correlated experimental parameters such as number laser pulses, fluence ambient gas pressure. capability CEMS distinguish atomic surrounding combination its sensitivity makes it indispensable tool for a proper investigation optimisation treatments. Additional analytical techniques used order complementary information. Ion beam analysis (Rutherford backscattering spectrometry resonant nuclear reaction analysis) was measure depth profiles nitrogen carbon, while X-ray diffraction Rietveld refinement were employed characterize morphology irradiated samples. results revealed that under conditions, treatment can produce almost homogeneous layers nitride/carbide, where composition structure are determined only by irradiation.