Method and System of Ultrafast Laser Writing of Highly-Regular Periodic Structures

A method, a product by the method and device of preparation of highly-regular periodic structure using a pulsed laser beam irradiating a spot on a surface of a substrate are disclosed. The method of direct formation of highly-regular periodic structure on a materials uses activation of Surface Electromagnetic Wave (SEW) interfering with the laser beam on the surface of the substrate in a manner which ensures high quality and regularity of the obtained pattern.(FR)La présente invention concerne un procédé, un produit obtenu par le procédé et un dispositif de préparation d'une structure périodique très régulière à l'aide d'un faisceau laser pulsé irradiant un point sur une surface d'un substrat. Le procédé de formation directe d'une structure périodique très régulière sur des matériaux utilise l'activation d'une onde électromagnétique de surface (SEW) interférant avec le faisceau laser sur la surface du substrat de manière à assurer une qualité et une régularité élevées du motif obtenu

Tribological Properties of High-Speed Uniform Femtosecond Laser Patterning on Stainless Steel

In this work, an analysis of the tribological performance of laser-induced periodic surface structures (LIPSS) treated X5CrNi1810 stainless steel was conducted. The approach followed by authors was to generate LIPSS-patterned circular tracks, composed of radial straight grooves with uniform angular periodicity. This permitted to measure the tribological properties in a pin-on-flat configuration, keeping fixed the orientation between the grooves and the sliding direction. A Stribeck curve was measured, as well as the consequent wear. A deep analysis of the sub-surface conditions after LIPSS generation was moreover performed using Focused Ion Beam (FIB) cross-section

Tribological Properties of High-Speed Uniform Femtosecond Laser Patterning on Stainless Steel

In this work, an analysis of the tribological performance of laser-induced periodic surface structures (LIPSS) treated X5CrNi1810 stainless steel was conducted. The approach followed by authors was to generate LIPSS-patterned circular tracks, composed of radial straight grooves with uniform angular periodicity. This permitted to measure the tribological properties in a pin-on-flat configuration, keeping fixed the orientation between the grooves and the sliding direction. A Stribeck curve was measured, as well as the consequent wear. A deep analysis of the sub-surface conditions after LIPSS generation was moreover performed using Focused Ion Beam (FIB) cross-section

Superhydrophilic properties driven by highly-regular laser-induced periodic structures on Si surface

In this work an investigation about the effects of high-speed, highly-regular laser induced periodic surface structures (HR-LIPSS) on wetting properties of silicon surface are presented and discussed. In order to investigate the influence of chemistry on wetting properties of textured surfaces, treatments were performed both under air and N2 shielding gas. The morphology was investigated by Scanning Electron Microscope (SEM), the chemistry by energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy and the wetting properties by camera recording. The results demonstrate substantial effects of HR-LIPSS on wetting properties of silicon surface. The hydrophilic Si surface becomes superhydrophilic after femtosecond nanopatterning and the addition of N2 in laser treated zone essentially influences the chemistry of the surface, this permits to control the water flowing and makes HR-LIPSS more flexible, bringing up to a new level of control of wettability properties for several applications

Impact of Ultrashort Laser Nanostructuring on Friction Properties of AISI 314 LVC

Laser irradiation yields a powerful tool to modify the symmetry and asymmetry features of materials surfaces. In this paper, femtosecond laser-induced periodic surface structures were applied on stainless steel AISI 314, specially hardened by a low-vacuum carburizing procedure. Symmetry modifications in the surface’s morphology and chemistry before and after the laser treatment were investigated by SEM and EDS, respectively. Coefficient of friction (COF) was observed in dry sliding condition by using block-on-ring sliding test. The results show that COF values are substantially lower after laser-induced periodic surface structures (LIPSS) surface treatment

Ultrafast laser texturing on Si with burst-mode picosecond laser pulses

Picosecond laser-induced periodic surface structures (PLIPSS) have been fabricated on surface of Si in uniform and burst-mode regimes at a high speed. The effects of burst-mode respect to uniform one are examined in term of chemical, mechanical and morphological properties

Structure, phase composition and microhardness of vacuum-arc multilayered Ti/Al, Ti/Cu, Ti/Fe, Ti/Zr nano-structures with different periods

The microstructure, phase composition and microhardness of multilayered Ti/Al, Ti/Cu, Ti/Fe and Ti/Zr condensates produced on stainless steel substrates via vacuum-arc evaporation of pure metals were studied. The sublayer periods (Λ) were regulated in the range 80–850 nm by varying the vacuum discharge current and the duration of the successive depositions of metallic plasma onto the substrates while maintaining the total deposition time constant. The regularity of the obtained nanostructures was investigated by scanning and transmission electron microscopy while phase compositions were identified with X-ray diffraction (XRD) analysis in order to evidence the presence of interdiffusion and the amount of intermetallics. Condensates cross sections were mechanically characterized by means of microhardness tests. Measurements were correlated to the periods and to the presence of intermetallics

Highly regular nanostructuring of Si surface by ultrashort laser pulses

Sub-MHz repetition rate femtosecond laser pulses produce extremely regular periodic surface structures on silicon surface due to competition between ultrafast heating and electron-emission. They allow manufacturing of novel devices for solar, optoelectronic, and biomedical applications