@conference{
author = "Božinović, Nevena and Milovanović, Dubravka S. and Rajić, Vladimir and Rakočević, Lazar and Savović, Jelena and Petrović, Suzana",
year = "2021",
abstract = "Design of surface patterning with the co-existence of micro- and nanoscale features by picosecond laser processing is investigated in order to improve cell integration. New biomedical Ti alloys with a high concentration of β-stabilizer elements (zirconium) are developed, as potential solutions to the mismatch between the Young’s modulus of the implant and the surrounding hard tissues. On the other hand, in order to enhance the tribological and antimicrobial properties of Ti/Zr coating, a novel titanium-copper and titanium-copper-zirconium thin film systems were designed in this work. Novel composite structure composed of subsurface distributed Cu and Zr layers (thickness of 10 nm), with satisfying mechanical properties and moderate biocompatibility, were deposited by ion sputtering on Si substrate to the total thickness of 300 nm. The multilayer thin films were irradiated by focused linearly p-polarised picosecond pulses with follow characteristics: repetition rate of 10 Hz, pulse duration equal to 150 ps, central wavelength of 1064 nm and 120 µm Gaussian spot diameter. The changes of the composition and surface morphology in the Ti/Cu/Ti/Si and Ti/Cu/Zr/Ti/Si multilayer thin films were monitored by X-ray photoelectron spectroscopy (XPS), by scanning electron microscopy (SEM) and by profilometry. The main part of the absorbed laser energy was rapidly transformed into heat, producing intensive modifications of composition and morphology on the multilayer surface [1,2]. The results show an increase in surface roughness, formation of a specific surface topography, appearance of hydrodynamic features and ablation of surface material. XPS analysis revealed that laser modification was induced intermixing between the Cu and Zr layers, but also with dominant Ti component. During the laser processing of Ti/Cu/Ti/Si and Ti/Cu/Zr/Ti/Si multilayer thin films, delivered energy was sufficient to cause solid-state reactions, the formation of alloy between components. Laser processing of Ti/Cu/Ti/Si and Ti/Cu/Zr/Ti/Si multilayer thin films is used to create the arrayed surface structure, such as laser-induced periodic surface structures (LIPSS) and at the same time to induce mixing of components inside the thin film structures, as well as the formation of ultrathin oxide layer at the laser-treated surfaces [3,4]. Laser surface patterns are organized as networks and parallel lines, where lines formed of LIPSS are wide up to 100 μm and distance between lines are less than 300 μm. The average periodicity between LIPSSs was about 900 nm, which would correspond to the formation of low spatial frequency LIPSS (LSFL).",
publisher = "Belgrade : Institute of Physics Belgrade",
journal = "PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade",
title = "Laser surface texturing of Ti/Cu/Ti/Si and Ti/Cu/Zr/Ti/Si multilayer thin films",
pages = "153",
url = "https://hdl.handle.net/21.15107/rcub_vinar_10913"
}