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1
Content available Application of laser treatment technology for boiling heat transfer augmentation
100%
Orman Ł. J. , Radek N. , Honus S. , Pietraszek J.
Production Engineering Archives
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2024
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tom Vol. 30, Iss. 2
259--265
EN
Boiling heat transfer can be enhanced when the heater’s surface morphology is altered. The paper discusses the use of the laser beam to produce efficient heat exchangers. Two types of samples were investigated with distilled water and ethyl alcohol as boiling agents. The specimens differed with the height of the microfins: 0.19 mm and 0.89 mm. It was observed that both of them enhanced boiling heat transfer in comparison to the smooth reference surface. However, the sample with higher micro-fins performed better, especially in the region of low temperature differences, where the heat flux was about three times higher than in the case of the smaller microfins. The comparison of the experimental data with selected models of boiling heat transfer revealed significant differences with regard to the heat flux. The laser-made samples dissipated larger heat fluxes than it could be anticipated according to the models. It might be linked with high surface roughness of the area between the microfins, generated as a result of the laser beam interaction with the surface.
2
Content available remote Laser forming of steel tubes
100%
Radek N. , Kurp P. , Pietraszek J.
Technical Transactions
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2019
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tom Vol. 116, iss. 1
223--229
EN
The paper presents a study on microstructure and microhardness changes obtained in the spun carbon steel tube after shaping by a laser beam. The surface of a pipe was machined circumferentially using a 1500 W CO2 laser beam at various diameters (distance from the focus). As a result, plastic deformations such as convex and narrowing shape changes were observed. The conducted research, including microhardness measurements, shows that, in comparison to the unprocessed material, the microstructure was significantly changed, both in the convex and narrowed layer.
PL
W pracy przedstawiono badania zmian mikrostruktury i mikrotwardości warstwy wierzchniej wyoblonej i przewężonej rury ze stali węglowej po laserowym kształtowaniu. Powierzchnia rury była skanowana po obwodzie wiązką lasera CO2 o mocy 1500 W przy różnych średnicach (odległościach od ogniska). W efekcie uzyskano odkształcenia plastyczne, takie jak wyoblenie i przewężenie rury. Przeprowadzone badania, w tym pomiary mikrotwardości, wykazują, że mikrostruktura uległa istotnej zmianie w stosunku do materiału rodzimego, zarówno w warstwie wyoblonej, jak i przewężonej.
3
Content available Reliability of variability source detection in Shainin's component search procedure
100%
Pietraszek J. , Dwornicka R. , Goroshko A.
Quality Production Improvement - QPI
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2019
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tom Vol. 1, Iss. 1
358--362
EN
Shainin's component search procedure uses variability source detection based on specific median test. This approach has only two triple subsets and the certainty of inference can be weak for this reason. This paper checks this approach by series of numerical simulations.
4
Content available Influence of laser texturing on tribological properties of DLC coatings
100%
Radek N. , Tokar D. , Kalinowski A. , Pietraszek J.
Production Engineering Archives
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2021
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tom Vol. 27, Iss. 2
119--123
EN
The work presents the use of laser texturing of DLC coatings to improve tribological properties. The coatings were applied by the PVD method to the rings made of 4H13 steel. The surface texturing was = 343 nm.performed with the TruMICRO 5325c picosecond laser with the radiation wavelength The surface microstructure analysis, surface microgeometry and microhardness measurements and tribological tests were carried out. The problem presented in the paper can be used to extend the knowledge of the areas of application of DLC coatings, especially in sliding friction pairs.
5
Content available Discussion of the heat flux calculation method during pool boiling on meshed heaters
100%
Orman Ł. J. , Radek N. , Pietraszek J. , Gontarski D.
System Safety : Human - Technical Facility - Environment
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2020
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tom Vol. 2, nr 1
247--252
EN
The paper discusses nucleate boiling heat transfer on meshed surfaces during pool boiling of distilled water and ethyl alcohol of very high purity. It presents a correlation for heat flux developed for heaters covered with microstructural coatings made of meshes. The experimental results have been compared with the calculation results performed using the correlation and have been followed by discussion. Conclusions regarding the heat flux determination method have been drawn with the particular focus on the usefulness of the considered model for heat flux calculationson samples with sintered mesh layers.
6
Content available Production of zinc coatings by electro-spark deposition
100%
Radek N. , Pietraszek J. , Klimecka-Tatar D.
System Safety : Human - Technical Facility - Environment
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2020
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tom Vol. 2, nr 1
253--258
EN
The paper describes the method of producing a zinc coating on steel by electro-spark deposition technology. The technology of applying electro-spark zinc to the surface was presented. Microscopic observations and corrosion resistance tests were made. The possibilities of practical application of this type of coatings in the process of repairing zinc coatings, either damaged or with manufacturing defects, were analyzed.
7
Content available The smoothed bootstrap fine-tuning
100%
Dwornicka R. , Goroshko A. , Pietraszek J.
System Safety : Human - Technical Facility - Environment
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2019
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tom Vol. 1, nr 1
716--723
EN
The bootstrap method is a well-known method to gather a full probability distribution from the dataset of a small sample. The simple bootstrap i.e. resampling from the raw dataset often leads to a significant irregularities in a shape of resulting empirical distribution due to the discontinuity of a support. The remedy for these irregularities is the smoothed bootstrap: a small random shift of source points before each resampling. This shift is controlled by specifically selected distributions. The key issue is such parameter settings of these distributions to achieve the desired characteristics of the empirical distribution. This paper describes an example of this procedure.
8
Content available Challenges for the DOE methodology related to the introduction of Industry 4.0
100%
Pietraszek J. , Radek N. , Goroshko A. V.
Production Engineering Archives
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2020
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tom Vol. 26, Iss. 4
190--194
EN
The introduction of solutions conventionally called Industry 4.0 to the industry resulted in the need to make many changes in the traditional procedures of industrial data analysis based on the DOE (Design of Experiments) methodology. The increase in the number of controlled and observed factors considered, the intensity of the data stream and the size of the analyzed datasets revealed the shortcomings of the existing procedures. Modifying procedures by adapting Big Data solutions and data-driven methods is becoming an increasingly pressing need. The article presents the current methods of DOE, considers the existing problems caused by the introduction of mass automation and data integration under Industry 4.0, and indicates the most promising areas in which to look for possible problem solutions.
9
Content available remote Analiza struktury geometrycznej powierzchni systemów powłokowych antygraffiti przeznaczonych do zabezpieczania taboru kolejowego
100%
Radek N. , Pasieczyński Ł. , Pietraszek J. , Bronček J.
Mechanik
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2019
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tom R. 92, nr 2
124--127
PL
W artykule przedstawiono wyniki badań właściwości systemów powłokowych antygraffiti do zabezpieczania taboru kolejowego. Ocenę tych właściwości przeprowadzono na podstawie pomiarów struktury geometrycznej powierzchni oraz analizy mikrostruktury. Badano następujące systemy powłokowe antygraffiti: XPC 60011, XPC 60012, XPC 60036, BO100-AGR. Składały się one z następujących warstw: antykorozyjnego podkładu epoksydowego, szpachli, podkładu wypełniającego, lakieru bazowego oraz bezbarwnych lakierów antygraffiti. Powłoki zostały naniesione na próbki ze stali S355 za pomocą pistoletów firmy SATA. Ze względu na swoje właściwości systemy powłokowe antygraffiti mogą być z powodzeniem stosowane do zabezpieczania pojazdów szynowych.
EN
The paper presents the results of the properties of anti-graffiti coating systems for rolling stock. The determination was based on measurements of surface geometric structure and analysis of microstructure. The tests were carried out on the following anti-graffiti coating systems: XPC 60011, XPC 60012, XPC 60036, BO100-AGR. The above systems consisted of the following layers: corrosion epoxy primer, putty, primer filler, basecoat and clearcoats anti-graffiti. The coatings were applied to the sample with S355 steel using guns SATA. Because of its properties, anti-graffiti coating systems can be successfully used on rail vehicles.
10
Content available Critical analysis of pool boiling correlations
100%
Radek N. , Orman Ł. J. , Honus S. , Pietraszek J.
System Safety : Human - Technical Facility - Environment
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2023
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tom Vol. 5, iss. 1
258--265
EN
The manuscript describes the problem of boiling heat flux determination with the focus on nucleate boiling mode. It presents the boiling phenomenon on the bare surface and provides a review of the correlations that can be used for modelling purposes. Two most commonly applied correlations were validated against the experimental results. One of them showed significant discrepancies, which might be attributed to the conditions of the research and possible variations in the morphology of the heater. The other correlation proved to be successful in determining heat flux.
11
Content available The bootstrap method as a tool to improve the design of experiments
100%
Dwornicka R. , Radek N. , Pietraszek J.
System Safety : Human - Technical Facility - Environment
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2019
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tom Vol. 1, nr 1
724--729
EN
The paper considers the use of the bootstrap method to improve the determination of confidence intervals identified by the DOE (design of experiment) procedure. Two different approaches have been used: one that is appropriate for factorial designs and the other one relevant to the methodology of the response surface. Both approaches were tested on the real experiment datasets and compared with the results obtained from the classical statistical expressions based on well known asymptotic formulas derived from the distribution.
12
Content available Operational properties of the cermet electro-spark coatings after laser treatment – technology and application
100%
Radek N. , Pietraszek J. , Konstanty J.
System Safety : Human - Technical Facility - Environment
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2019
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tom Vol. 1, nr 1
797--804
EN
The paper is concerned with determining the influence of the laser treatment process on the properties of electro-spark coatings. The properties of the coatings after laser treatment were assessed based on following methods: microstructure and X-ray diffraction analysis, adhesion tests, roughness measurement, hardness tests, tribological properties and application tests. The tests were carried out on WC-Co coating (the anode) obtained by electro-spark deposition over carbon steel C45 (the cathode) and molten with a laser beam. The coatings were deposited by means of the EIL-8A and they were laser treated with the Nd:YAG. The tests show that the laser-treated electro-spark deposited WC-Co coatings are characterized by lower hardness, higher seizure resistance, roughness and adhesion. The laser treatment process causes the homogenization of the chemical composition, the structure refinement and the healing of microcracks and pores of the electro-spark deposited coatings. Laser treated electro-spark deposited coatings are likely to be applied in sliding friction pairs and as protective coatings.
13
Content available Phase change heat exchangers made of pin-fins for boiling enhancement
100%
Orman Ł. J. , Radek N. , Pietraszek J. , Gontarski D.
Quality Production Improvement - QPI
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2019
|
tom Vol. 1, Iss. 1
433--439
EN
The paper deals with the important issue of boiling heat transfer enhancement using mechanical treatment of the heater surface. The surface has been modified in such a way that microfins have been produced. The application of such a structure leads to highly increased heat fluxes in relation to the smooth surface as has been presented and discussed in the paper. The experiments including distilled water and ethyl alcohol on the horizontal copper samples of 3 cm diameter have been considered. The heat flux value of microfinned surface was even nine times higher than the heat flux dissipated from the smooth surface without any coating. It proves a considerable enhancement of boiling with the application of the mechanically treated surfaces of heat exchangers.
14
Content available Laser surface texturing: characteristics and applications
75%
Kalinowski A. , Radek N. , Orman Ł. , Pietraszek J. , Szczepaniak M. , Bronček J.
System Safety : Human - Technical Facility - Environment
|
2023
|
tom Vol. 5, iss. 1
240--248
EN
Laser surface texturing (LST) has emerged as a versatile and efficient technique for modifying surface properties across various materials. This paper provides an analysis of the characteristics and diverse applications of laser surface texturing. The paper begins by explaining the fundamental principles underlying LST, highlighting the mechanisms involved in material interaction and the resultant surface modifications. It explores the influence of laser parameters such as pulse duration, energy density, and wavelength on the texturing process, emphasizes their impact on surface morphology, roughness, and topographical features. Furthermore, this paper delves into the wide-ranging applications of LST across different industries and fields. It examines how LST enhances surface functionalities, including improvements in tribological properties, wettability, friction reduction, and biocompatibility. Additionally, the utilization of LST for creating microstructures enabling advanced functionalities in optics, electronics, biomedical devices, and energy harvesting systems is discussed. Moreover, the challenges and future directions in LST technology are highlighted, which encompass advances in precision, scalability, and integration of LST with other manufacturing processes. The potential environmental implications and economic feasibility of LST are also discussed.
15
Content available Formation of coatings with technologies using concentrated energy stream
63%
Radek N. , Kalinowski A. , Pietraszek J. , Orman Ł. J. , Szczepaniak M. , Januszko A. , Kamiński J. , Bronček J. , Paraska O.
Production Engineering Archives
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2022
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tom Vol. 28, Iss. 2
117--122
EN
A number of modern surface processing methods use an energy flux. The examples include electro-spark deposition (ESD) and laser beam processing (LBP). The work concerns the study of Cu-Mo coatings deposited on C45 carbon steel, which were then eroded with a laser beam. The analysis included the analysis of the microstructure, measurements of macrogeometry and microhardness, corrosion resistance tests of selected areas after laser treatment. The coatings were applied with ELFA-541 and subjected to Nd:YAG laser treatment with variable laser parameters. The problem presented in the work can be used to extend the knowledge of the areas of application of ESD coatings, especially in sliding friction pairs.
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