Now showing 1 - 10 of 55
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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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Modification of Aluminum 1050 and 2219 Alloys Using CuBr Nanosecond Laser for Hydrophobic and Hydrophilic Properties

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

This study investigates the use of a CuBr vapor nanosecond laser with a 510 nm/578.2 nm wavelength for the surface treatment of 1050 aluminum and 2219 aluminum alloys. Laser-induced periodic surface structuring was used to optimize processing parameters to achieve hydrophobic and hydrophilic properties on the surface. The wetting properties were measured and the roughness results (Ra, Rz, Rq) evaluated. Prior to and after laser treatment, surface wetting and roughness changes were investigated. The wetting study showed that the maximum contact angle between a droplet of deionized water and the treated surface can be reached between more than 140 degrees and less than 10 degrees, which, respectively, is a superhydrophobic and superhydrophilic surface. Compared with the untreated surface, wetting increased by more than 2 times and decreased by more than 8 times. Overall, experiments show the dependence of wetting properties on laser input parameters such as scan speed and scan line distance with different delivered energy amounts. This study demonstrates the possibility of laser parameter optimizations which do not require auxiliary gases and additional processing of the resulting surfaces to obtain different wetting properties on the surface. The findings described in this article suggest that the CuBr laser surface treatment method is a promising method for industrial applications where surfaces with special wetting and roughness properties are required, for example, the laser marking of the serial number of parts used in wet environments such as aerospace, shipbuilding, and defense industries.

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INVESTIGATION OF SURFACE ROUGHNESS OF CARBON STEEL MACHINED PARTS AFTER NANOSECOND FIBER LASER MARKING

2023, Petar Tsvyatkov, Emil Yankov, Lazov, Lyubomir, Teirumnieks, Edmunds, Pīgožnis, Kārlis

Laser marking with a nanosecond fiber laser is one of the most common ways to permanently mark various engineering materials. The roughness of the machined surface and its observation is essential to evaluate the impact on the contrast of the marking as well. Experimental studies of the roughness obtained as a result of the laser marking, were inspected using a 3D measuring laser microscope OLYMPUS LEXT OLS5100. Analysis of the graphical dependence of the roughness function on the four process parameters: laser power, frequency, speed of marking and step.

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Mathematical Model of Forecasting Laser Marking Experiment Results

2016, Pavels Narica, Teilāns, Artis, Lazov, Lyubomir, Pavels Cacivkins, Teirumnieks, Edmunds

Method allows for modelling of the anticipatory results of colour laser marking experiments. The process of calculating expected results takes into consideration the construction specifics of laser system being used and displays the results in compact form of a set of parameter matrices that have their values conditionally formatted as colour maps for easy identification of complex patterns. The complete set of all the related parameter matrices, both technical and derived, as well as the specific relations between them form the mathematical model of forecasting laser marking experiment results. Because the mathematical model is implemented within spreadsheet processor, it can be instantiated multiple times for any number of experiments.

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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.

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Effect of Laser Marking Speed, Power and Pitch on Hardness and Roughness of Aisi 304l

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

In this study, an experiment was conducted to change the technological properties of the surface by infra-red laser marking. The influence of power, speed and raster step was investigated. These parameters during laser marking of AISI 304L steel have a significant change on the microhardness and surface roughness. It was found that high stiffness is achieved at higher powers and small pitch. An analysis of the results showed that as the raster step increases, the roughness of the marked sample decreases. The influence of linear energy density and overlap factor on the process was also investigated. The microhardness of the treated surfaces increases with an increase in the linear energy density and the overlap coefficient, and in the first case the dependence is almost linear, and in the second - non-linear.

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Mathematical Model of the Distribution of Laser Pulse Energy

2016, Pavels Narica, Teilāns, Artis, Lazov, Lyubomir, Pavels Cacivkins, Teirumnieks, Edmunds

Method allows for modelling of the complex process of laser pulse energy distribution over flat work surface. The process of calculating the correct result does not use common lasing formulas but instead employs the mathematical model of matrix multiplication of three input matrices representing a pulse model, a line model, and a plane model. The pulse model represents the distribution of planar energy densities within the laser pulse. The line model represents the distribution of pulses within the line. The plane model represents the distribution of lines within the plane. Because mathematical model is implemented within a spreadsheet processor, its size can be adjusted as needed and it can be instantiated multiple times for simultaneous modelling of different input parameters.

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METHOD FOR COLOR LASER MARKING PROCESS OPTIMIZATION WITH THE USE OF GENETIC ALGORITHMS

2017, Pavels Narica, Lazov, Lyubomir, Teilāns, Artis, Grabusts, Pēteris, Teirumnieks, Edmunds, Pavels Cacivkins

Optimization of color laser marking process mostly depends on effective identification of optimal values of laser marking parameters. This is a difficult combinatorial optimization problem, which is still essential for companies that use laser marking systems. The study proposes a new approach to the process optimization through the use of genetic algorithms, carrying out preliminary experimental investigation, analyzing the laser marking results, and presenting possible improvements to the current implementation of genetic algorithms.

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INVESTIGATION OF THE INFLUENCE OF TECHNOLOGICAL PARAMETERS OF LASER MARKING ON THE DEGREE OF CONTRAST

2023, Petar Tsvyatkov, Emil Yankov, Lazov, Lyubomir, Teirumnieks, Edmunds, Pīgožnis, Kārlis

In modern production, each finished product entering the market is identified by a special marking. Each mark must meet requirements such as good coding, easy to see, easy to read by certain readers, stable over time, etc. In the present casting, laser marking of the C75 steel was carried out with a fiber laser with an average power of P = 30 W and a wavelength of λ = 1064 nm. For semi-contrast marking, marking speeds from 100 mm/s to 700 mm/s, average power from 10 to 30 W, raster pitch from 20 µm to 60 µm, scanning frequency from 20 kHz to 150 kHz were investigated as constant parameters are the pulse duration τ =100 ns, number of repetitions N = 1 and defocus Δ f = 0 mm. The influence of the changing parameters on the contrast was established, and experimental dependences were constructed. The achieved research results show that to obtain a high contrast mark, the average power should be above 20 W, the scanning speed up to 300 mm/s, the scanning frequency up to 50 kHz and the raster pitch up to 40 µm.

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Processing composite materials with lasers

2023, Teirumnieka, Ērika, Pīgožnis, Kārlis, D Blumberga, Teirumnieks, Edmunds, Lazov, Lyubomir

Composite materials, consisting of fibers and binders of natural and artificial origin, are increasingly used in various fields of industry. Processing of the obtained materials into finished forms is often difficult and expensive. Treatment of composite materials, such as milling, cutting, or grinding, is currently dominant. At present, lasers are increasingly used in production processes. It should be noted that modern industrial production is unthinkable without the use of laser equipment. However, when using lasers, initial adjustment of their laser parameters is required for optimal material processing. When considering different lasers and materials to be processed, the setting parameters are different and the obtained processing quality is varied. In the research, samples of composite materials have been made, consisting of epoxy resin as a binder and hemp, flax, and carbon fibers as reinforcing materials. The obtained composite materials have been studied with fiber laser for their processing quality.