Austenite modification of AISI 316L SS by pulsed nitrogen ion beams generated in dense plasma focus discharges

Jorge Feugeas , L. Rico , L. Nosei , B.J. Gomez , E. Bemporad , Jacky Lesage (1) , J. Ferron (2)

1 LML - Laboratoire de Mécanique de Lille - FRE 3723
2 TIMA - Techniques de l'Informatique et de la Microélectronique pour l'Architecture des systèmes intégrés

We present the results of a surface modification of AISI 316L stainless steel by surface irradiation with high energy, pulsed nitrogen ion beams generated with 0.8 kJ dense plasma focus. The surface characterization was done using GAXRD, Auger electrons spectroscopy, TEM and optical microscopy. After the irradiation, we found a modification of a 1 μm thick surface layer, on which a gradual lattice expansion of the austenite with the number of irradiation pulses, i.e. with the total nitrogen ion fluence, was observed. In addition, ~ 40 nm close to the surface layer, a disordered lattice structure had been observed through TEM analysis. Those results can be explained in terms of the extreme thermal effect induced on the surface through the fast high energy release during the pulsed ion interaction with the steel surface, followed by an also rapid cooling down process which limits the nitrogen diffusion to the bulk.

Mots clés: Plasma wall interaction; Ion nitriding; Expanded austenite; Z-pinch; Plasma focus; Nanofilms; Austenitic stainless steel; Tribology

Jorge Feugeas, L. Rico, L. Nosei, B.J. Gomez, E. Bemporad, et al.. Austenite modification of AISI 316L SS by pulsed nitrogen ion beams generated in dense plasma focus discharges. Surface and Coatings Technology, 2010, 204 (8), pp.1193-1199. ⟨10.1016/j.surfcoat.2009.10.034⟩. ⟨hal-00526501⟩