magistrsko delo magistrskega študijskega programa II. stopnje Strojništvo
Matej Senegačnik (Author), Peter Gregorčič (Mentor)

Abstract

V magistrskem delu razvijemo in postavimo laserski sistem za mikrovrtanje in strukturiranje različnih kovinskih površin na mikrometrski in podmikrometrski skali. Pri tem smo uporabili različne laserske vire: Nd:YAG laser ([lambda] = 1064 nm) z ultrakratkimi 8 ps in 30 ps bliski; in vlakenski laser ([lambda] = 1060 nm) s spremenljivo dolžino bliskov od 10 ns do 240 ns. Mikrovrtanje smo izvajali na 28 [mi] m debeli jekleni in 32 [mi] m debeli titanovi foliji, strukturiranje površine pa na poliranih vzorcih jekla, titana in aluminija. Površine smo ovrednotili z optičnim mikroskopom, z vrstično elektronsko mikroskopijo (SEM) in z disperzijsko spektroskopijo rentgenskih žarkov (EDS). Rezultati kažejo, da je z laserskim vrtanjem možno izdelati mikroluknje s premerom velikosti valovne dolžine svetlobe (~1 [mi] m) ter da na obliko lukenj pomembno vpliva tudi polarizacija svetlobe. Raziskali smo tudi vpliv procesnih parametrov na nastanek, periodo in orientacijo lasersko povzročenih periodičnih površinskih struktur (LIPSS). Vrednotenje spremembe površinske kemije (masni delež kisika) v odvisnosti od celokupne energije po laserski obdelavi kaže, da se vsebnost kisika s celokupno energijo bliskov veča do zasičenega stanja, ki v našem primeru znaša okoli 18%. Pojasnimo tudi različne razloge za obarvanje kovinskih površin ter predstavimo vpliv okoliške atmosfere na nastanek hierarhične površinske strukture. Doseženi rezultati so pomembni z vidika nadaljnjih raziskav, ki bodo vodile do razvoja novih površin z unikatnimi funkcionalnostmi.

Keywords

magistrske naloge;laserski inženiring površin;laserske obdelave;lasersko strukturiranje;lasersko mikrovrtanje;lasersko barvanje;lasersko povzročene periodične površinske strukture;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FS - Faculty of Mechanical Engineering
Publisher: [M. Senegačnik]
UDC: 621.9.048.7(043.2)
COBISS: 16290075 Link will open in a new window
Views: 984
Downloads: 607
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Other data

Secondary language: English
Secondary title: Laser-induced modification of metal surfaces on micrometer and submicrometer scale
Secondary abstract: In the master's thesis we develop and build a laser system enabling microdrilling and structuring of various metal surfaces on micrometer and submicrometer scale, by different laser sources: Nd:YAG laser ([lambda] = 1064 nm) with ultrashort 8-ps and 30-ps pulses; and a fiber laser ([lambda] = 1064 nm) with pulses of variable lengths, from 10 ns to 240 ns. Microdrilling was performed into 28- [mi] m-thick steel foil and 32- [mi] m-thick titanium foil, while the surface structuring was carried out on polished samples of steel, titanium and aluminium. Processed surfaces have been characterized using optical microscope, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). Results show, that microholes with diameters in range of the laser wavelength (~1 [mi] m) can be laser drilled. The effect of beam polarisation on the shape of the holes is also presented. We have investigated the effect of processing parameters on growth, period and orientation of laser-induced periodic surface structures (LIPSS). Evaluation of changes in surface chemistry (mass fraction of oxygen) with dependence on total irradiated pulse energy shows that the oxygen content is increasing with total pulse energy up to a saturation level, which in our case equals 18%. We explain different reasons for coloring of metals and present the effect of surrounding atmosphere on development of hierarchical surface structures. The accomplished results are important for further development of new surfaces with unique functionalities.
Secondary keywords: laser structuring;laser microdrilling;laser-induced periodic surface structures;pulse polarisation;laser coloring;hierarchical surface structure;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. Ljubljana, Fak. za strojništvo
Source comment: Univerzitetna Prešernova nagrada / University Prešern Award 2018
Pages: XXIV, 86 str.
ID: 10958866