REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

Surface modification of WTi/Si thin film and stainless steel by picosecond laser irradiation

Dubravka MilovanoviĆ

VINČA Institute of nuclear sciences, University of Belgrade, Serbia, duca@vin.bg.ac.rs

Suzana petroviĆ

VINČA Institute of nuclear sciences, University of BelgradeSerbia, spetro@vin.bg.ac.rs

MILORAD ANĐELKOVIĆ

Grammar school “Svetozar Marković”, Surdulica, Serbia,

MILOŠ TODOROVIĆ

Chemical and food technology school, Belgrade, Serbia,

STEPAN STANČIĆ

Grammar school Pirot, Pirot, Serbia,

MILICA VESELINOVIĆ

First Belgrade gymnasium, Belgrade, Serbia,

MARIJA BJELAN

Tenth gymnasium “Mihajlo Pupin”, Belgrade

Abstract: Surface effects resulting from the picosecond laser ablation of stainless steel and WTi/Si are discussed in this work. The surface of the sample was irradiated by Nd:YAG laser at 1064 nm wavelenght, with the different count of pulses at constant pulse energy. Morphological changes of the induced prominent ablation were registered and analyzed. Various analytical techniques were used for characterization of the samples before and after laser irradiation. Surface morphology was monitored by optical microscopy and SEM. Crater depth and surface profile analysis was done by non-contact optical profilometer. Also, an important parameter - the laser ablation threshold fluence (F_th) of these materials was calculated.

Keywords: Surface modification, laser, profilometry, stainless steel, thin films, Wti.