165 research outputs found

    Surface modifications of tin coating by pulsed TEA Co2 laser

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    Interactions of a TEA CO2 laser, 100 ns pulse, with titanium nitride (TiN) coating deposited on AISI D2 steel, were studied. The energy absorbed from the laser beam is partially converted to thermal energy, which generates a series of effects such as melting, vaporization of the molten material, shock waves, etc. Morphological modifications of the titanium nitride surface can be summarized as follows: (i) ablation of the TiN coating in the central zone of the irradiated area with creation of grainy and cracked features, (ii) appearance of a hydrodynamic structure like resolidified droplets of the material in the periphery region. The process of sample irradiation was accompanied by the appearance of plasma. Color modifications of the sample, upon laser irradiation, indicate possible chemical changes like oxidation.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

    Picosecond Laser Ablation of Silicon Single Crystal in a Liquid Environment

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    The picosecond Nd:YAG laser at wavelengths of 1064 nm was used to produced the silicon-based nanoparticles in de-ionized water. The main goal of our work presented here was enlight the role of thermal effects on the process of laser ablation of solid target in liquid. To accieve this goal the additional heating of the target surface by continuous laser was applied during the experiment. The shift of nanoparticles size distribution caused by applying of additional continuous laser was reported in this work. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3492

    Optical spectroscopy of plasma induced by irradiation of animal bone with TEA CO2 laser

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    The application of laser-induced breakdown spectroscopy (LIBS) for the elemental analysis of pig shoulder bone samples is reported. Measurements were performed using a compact laboratory-made TEA CO2 laser with low pulse energy. The recorded spectra consisted of well-defined lines of atoms and single charged ions of Ca, Mg, P, and other constituent elements, with a good signal-to-noise ratio suitable for spectrochemical analysis. Based on the ICP quantitative analysis of the bone sample, the limits of detection of LIBS analysis were estimated for Mg (16 ppm) and Na (940 ppm). Plasma parameters, temperature, and electron number density were determined by measuring Stark widths and relative intensities of the C and Mg ionic and atomic spectral lines.The book of abstracts available at: [http://www.socphyschemserb.org/media/physical-chemistry-2021/abstracts.pdf

    Surface modifications of TiN coating by pulsed ir lasers: tea CO2 and HF laser

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    Interactions of a pulsed Transversely Excited Atmospheric (TEA) CO2 and chemical HF laser with polycrystalline titanium nitride (TiN) coating deposited on high quality steel AISI 316, were studied. It was shown that both lasers, at energy densities of 43 J/cm2 and 38.6 J/cm2, induce morphological changes on the target. The HF laser produces more pronounced damage than the TEA CO2 laser. The energy absorbed from either of these lasers is mainly converted into thermal energy.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

    Picosecond pulsed laser ablation of silicon single crystal

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    Silicon-based nanoparticles (SiNPs) attract authors’ attention due its application prospects in a mutual field, from energy storage to bio-imaging. One of the most prominent methods for synthesis of SiNPs is pulsed laser ablation in liquid media (LAL), because it is simple, and it provides the minimum of contamination of the sample produced. Employed pulsed lasers in LAL are ns- and ps-, and the usage of fs- lasers are reported recently, as well. The objects of the LAL analyses are ablated craters on the Si target surface and, predominantly, the ablated material. Here, SiNPs are synthesized by ps- laser (150 ps, 1064 nm) ablation of Si single-crystal plates in de-ionized water. The focus of the work is the impact of the additional continuous wave (CW) laser (532nm) on the properties of the ablated material, i.e. SiNPs produced. The comprehensive analyses were performed, including the SiNPs’ size distribution, agglomeration abilities, aging, chemical properties (amount of oxygen and its distribution within the particles), and photoluminescence (PL) properties of the solution produced. It is demonstrated that PL properties of obtained SiNPs solution are impacted by introducing the CW laser in the ablation process. The peculiarity lies in the fact that such impact depends on both the PL excitation wavelength and the power of the introduced CW laser, which might open the possibility of successful tailoring of SiNPs produced by LAL.SPIG 2022 : 31st Summer School and International Symposium on the Physics of Ionized Gases : Contributed papers and abstracts of invited lectures, topical invited lectures and progress reports; September 5-9,2022, Belgrad

    Femtosecond laser surface texturing of aisi 1045 steel

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    Morphological changes, including texturing and production of highly oriented periodical surface structures (LIPSS), on AISI 1045 steel were carried out by femtosecond laser pulses. The surface changes, induced by laser, are highly localized with minimal hydrodynamic effects and without the presence of a debris. The produced LIPSS have the periodicity of 700 nm, and were more prominent in case of triple scanning. Elemental analysis of the surface showed chemical changes, due to formation of oxides and diffusion of carbon from the bulk. These changes are also more obvious in case of triple scanning

    Laser induced optical emission spectroscopy

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    Proceedings of the IX Belarusian-Serbian Symposium "Physics and Diagnostics of Laboratory and Astrophysical Plasmas" (РDР-9), September 16-21, Minsk, Belaru

    Applicability of TEA CO2 laser-based LIBS for the analysis of geological samples in air at atmospheric pressure

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    In this work, we present a study of the plasma generated by transversely excited atmospheric (TEA) CO 2 laser irradiation of a basalt sample. The plasma was induced in air at atmospheric pressure. For acquisition of emission spectra a time-integrated spatially resolved detection system was used. The excitation temperature was evaluated by the Boltzmann's plot method for selected Fe II spectral lines in the wavelength range 256-263 nm. The electron number density was determined from the Stark broadening of two iron lines, and results from both lines were identical within the experimental error. Signal to noise (SNR), ratio and limits of detection (LOD) for several elements were evaluated and compared to the results obtained using Nd:YAG laser and time-resolved LIBS measurements.Proceedings of the XI Belarusian-Serbian Symposium "Physics and Diagnostics of Laboratory and Astrophysical Plasmas" (РDР-11), December 15-19, Minsk, Belaru

    Optical emission measurement of plasma generated by infrared laser beam with Cu target

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    A study of visible (VIS) optical emission of Cu-plasma, induced by infrared (IR) Transversely Excited Atmospheric (TEA) CO2 laser, was carried out. Irradiation of the Cu-target with laser fluence of 8.2 J/cm2 at low air pressure resulted in the appearance of intensive plasma over the target. The type, number and intensity of the emission Cu-spectral lines strongly depend on the observing plasma location with respect to the target surface. “Primary” plasma gives the largest number of spectral lines. Also, in contrary to other plasma locations, some ionic lines were detected from this region. “Secondary” plasma, as a rule, gives the atomic lines. This region of plasma is very favourable for possible analytical applications (e.g. quantitative analysis)

    Femtosecond laser ablation and structuring of a hard bi-layered coating

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    We studied surface modification of a bi-layered coating (Al2O3/TiAlN/steel) induced by fs laser with single and multi-pulse irradiation. The laser pulses (λ=775 nm, τ=200 fs) were generated by a Ti:sapphire laser. The single pulse threshold fluence for ablation of the top Al2O3 layer was Dath =0.56 Jcm-2. Single pulse actions with fluence increased up to 16.47 Jcm-2 caused widening of ablated area without significant change of the TiAlN layer underneath. In case of multipulse irradiation, periodical surface structures (LIPSS) were induced on the TiAlN layer surface. The average periodicity of created LIPSS was 600 nm.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201
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