Now showing 1 - 10 of 62
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CARBON DIOXIDE (CO2) LASER MARKING PROCESS PARAMETER IMPACT ON MARK QUALITY OF POLIVINILCHLORIDE (PVC) MATERIAL

2017-04-19, Riekstiņš, Jānis, Sivenkovs, Artūrs, Lazov, Lyubomir, Narica, Pāvels

Laser technologies nowadays are widely used in material processing. CO2 laser systems in most cases are used in metallic material manufacturing and processing, taking not so big part in processing of plastic materials. This research is dedicated to find advantages or disadvantages and ways to use CO2 laser systems in plastic material processing, by taking PVC material as sample for experiments. PVC plastics is widely used in manufacturing of electrical installation details and devices, it is durable, relatively light, and cheap material. To provide application of various symbols, on the surface of plastic materials, can be used laser systems, which in long term can be more efficient than conventional marking methods. The aim of this work is to find if CO2 laser is appropriate for marking PVC material and to relate the mark quality parameters and the marking process parameters. The research was conducted in the period of time from March 2017 till April 2017, in the Rēzekne Academy of Technology, Physical process and laser technology research center.

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RESEARCH OF POSSIBILITIES OF LASER POLISHING OF THE SURFACE OF ALUMINUM

2021, Bulavskis, Kevins, Adijāns, Imants, Lazov, Lyubomir

The report considers the possibility of reducing the roughness after laser polishing of Aluminum plates. A CHANXAN CX-20G fiber laser with a wavelength of 1064 nm is used for the research. As a result of the experiment, 4 matrices were marked with a fiber laser on 3 samples for each series of the experiment. Then, using a multifunctional microscope, the roughness of the treated and untreated aluminum surface was measured. At the end of the research, conclusions were made about the changes in roughness in the course of this experiment.

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RESEARCH OF LASER MARKING AND ENGRAVING ON BRASS ALLOY 260

2019, Dainis Klavins, Lazov, Lyubomir, Antons, Pacejs, Ritvars Rēvalds, Zaicevs, Edgars

Brass Alloy 260 is widely used in mechanical engineering (odometer contacts, radiator cores), electrical engineering (electrical connectors, screw shells), plumbing (bathroom fixtures), consumers (watch parts, buttons, lamps) etc. The paper presents an analysis of the laser marking and engraving process. The ability Rofin powerline f20 laser system to engrave on Brass Alloy 260 is described. Recommendations are given on choosing the right parameters for laser marking and engraving of Brass Alloy 260 products.

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Artificial Neural Networks: What Can They Learn about Color Laser Marking?

2018, Pavels Cacivkins, Lazov, Lyubomir, Teirumnieks, Edmunds, Martins Sperga, Ingus Dilevka, Artis Vitins

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Investigation of the change in wettability properties and corrosion behavior of AISI 304 after laser surface texturing

2023, Adijāns, Imants, Lazov, Lyubomir, Ilieva, Mariana, Plamenova Nikolova, Maria

Stainless steel is a widely used material in industry, architecture, and medical instruments. However, after various thermal processing of stainless steels, chromium carbides can be formed, which locally depletes the chromium available to form a passive film and reduces the corrosion performance. Laser surface treatment can change the surface chemistry of the steel and improve some electrochemical characteristics. However, these characteristics are influenced by the laser power, pulse width, distance between the lines, scanning speed, etc., which all change the surface chemistry and characteristics of laser surface texturing. Simultaneously, the ability to repel liquids that cause corrosion actions could combine to enhance corrosion performance. Since the wettability of a solid surface depends both on its topography and chemical nature, the micro structuring of an austenitic steel surface is an effective way of fabricating hydrophobic or super hydrophobic corrosion-resistant surfaces. For this reason, this study discusses the effect of laser power in the impact zone and the distance between raster lines on the microstructure, wettability, and corrosion resistance of austenitic steel (AISI 304) when exposed to nanosecond fiber laser radiation. The results indicate that parameter-controlled micro structuring can be used to form both hydrophilic and hydrophobic surfaces with different electrochemical performances.

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INVESTIGATING THE IMPACT OF LASER POWER AND SCAN SPEED ON ENGRAVING ASPEN THERMOWOOD

2023, Rāviņš, Dzintars, Yankov, Emil, Adijāns, Imants, Lazov, Lyubomir, Rāviņš, Daivis

This study examines the effect of pre-heat treatment on laser engraving of aspen thermowood. We used an infrared CO2 laser with a wavelength of 10640 nm to engrave aspen thermowood samples with different pre-treatment temperatures, including one non-treated sample (base). The samples had a similar moisture content of about 6 - 8%, but exhibited different shades of brown depending on the pre-treatment temperature. The engraving depth and width were measured for each sample, and 8 graphs were constructed to analyze the results. Our findings show that pre-treatment temperature has a significant effect on the efficiency of laser engraving, with higher pre-treatment temperatures resulting in deeper engraving lines. The study provides valuable insights into the optimization of laser engraving parameters for aspen thermowood, and demonstrates the potential of pre-heat treatment to improve the quality of laser-engraved wooden products.

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Finite element modeling of laser aluminum marking

2021, Lazov, Lyubomir, N Angelov, I Draganov, A Atanasov, A Lengerov, Teirumnieks, Edmunds, I Balchev

This work makes use of the finite element model, whose results are validated by experiments. The effect is discussed of the speed on the laser marking process. Numerical experiments are performed to determine the temperature fields produced by laser pulses on samples of aluminum, a material with wide industrial uses. The numerical calculations are performed for the cases of a fiber laser and a CuBr laser. Plots are drawn of the temperature dependence on the speed for two power densities for both lasers. Preliminary working speed intervals are determined for the power densities used.

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Investigation of the influence of the processing speed and the linear pulse density of the laser surface texturing process

2023, Adijāns, Imants, Lazov, Lyubomir, Ilieva, Mariana, Plamenova Nikolova, Maria

Fine-tuning laser parameters is necessary to achieve the desired quality of the process of laser surface texturing. This requires a set of experiments to assess the influence of the main process parameters on the quality of the surface of a treated alloy. By varying the laser parameters, different laser-material interactions, such as heating, melting, or evaporation can be observed. This study analyzes the influence of two interrelated processing parameters in laser surface texturing – the speed of beam motion on the surface on the one hand, and, on the other, the linear pulse density. They ultimately have a direct impact on the resulting microstructure, hydrophilicity, and electrochemical properties of austenitic steel (AISI 304). By adjusting the pulse repetition rate of a 1064-nm fiber laser from 500 kHz to 1000 kHz at a constant speed of 100 mm/s, the surface wettability changes from hydrophobicity to hydrophilicity. All surfaces treated with laser scanning speeds varying from 20 mm/s to 200 mm/s at a constant rate of 500 kHz are hydrophobic. As a result, the changed ability to repel liquids alters the corrosion properties of the steel in a 0.5 M H2SO4 solution. The results allow one to distinguish ranges of laser-beam parameters that could be useful in selecting certain properties of the stainless-steel surface layer.

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LASER ABLATION OF PAINT COATINGS IN INDUSTRY

2021, Teirumnieks, Edmunds, Lazov, Lyubomir, Nikolay Angelov, Teirumnieka, Ērika, Adijāns, Imants, Antons, Pacejs

A comparison is made between the laser and sandblasting methods for removing paint from industrial facilities. The advantages of laser ablation are discussed. The possibilities of laser paint removal systems - stationary and moving - are shown. The main factors influencing the laser ablation process and the indicators that determine the quality of the obtained surface are systematized. Researchers' publications on this technological process are analyzed.

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Investigation of Surface Structure in the Laser Marking Process as a Function of Speed and Raster Step

2023, Emil Yankov, Lazov, Lyubomir, Teirumnieks, Edmunds, Nikolay Angelov, Adijāns, Imants, Antons, Pacejs

In this research, an experiment was conducted to change the technological properties of the surface by laser marking. The influence of the speed v of 50 mm/s, 75 mm/s and 100 mm/s and the raster step Δx from 20 µm to 80 µm at a constant average power P = 19.2 W and pulse duration τ = 4 ns was investigated. These parameters during the laser marking of AISI 304L steel have a significant change in microhardness and surface roughness. High hardness was found to be achieved at higher powers and small pitch. Analysis of the results showed that as the raster step increases, the roughness of the marked sample decreases. The effect of linear energy density and overlap factor on the process was also investigated. The microhardness of the machined surfaces increases with an increase in the linear energy density and the overlap coefficient, in the first case the dependence is almost linear, and in the second - nonlinear. Varying the marking speed and raster pitch in laser surface texturing of AISI 304L steel has a significant effect on the surface hardness and roughness, changing HV from 260 HV to 766.5 HV and Ra from 1.75 µm to 4.3 µm, respectively, which are the subject of the present analysis. research.