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PL
W artykule omówiono podstawowe odmiany laserowych źródeł energii stosowanych w procesach spawalniczych i pokrewnych spawalnictwu jak modyfikacja powierzchni i cięcie. Przedstawiono podstawy generowania wiązki fotonów w różnych odmianach laserów spawalniczych. Ogólnie porównano ich wybrane właściwości technologiczne i eksploatacyjne jak sprawność energetyczna, długość fali, jakość wiązki, sposób transportu wiązki fotonów, trwałość eksploatacyjna, koszt inwestycji, koszt eksploatacji oraz stopień skomplikowania serwisu. Wskazano rekomendacje do wyboru odmian spawania laserowego w przemyśle w zależności od uwarunkowań ekonomicznych i technicznych.
EN
This article discusses the basic types of laser energy sources using in welding and related processes, such as surface modification and cutting. It presents the fundamentals of photon beam generation in various types of welding lasers. A general comparison of their selected technological and operational properties, including energy efficiency, wavelength, beam quality, photon beam transport method, operational durability, investment cost, operating cost, and service complexity, is provided. Recommendations for selecting laser welding methods for industrial applications are provided based on economic and technical considerations.
EN
The objective to increase the transferred power (“heat”) of heat exchangers, here finned heat exchangers, leads to an increase in the heat transfer surfaces through thinner wall thicknesses and thus higher packing densities. This transfer can be further optimized by choosing materials with high heat transfer coefficients like copper. Various joining processes, such as welding or brazing can be used to complete the heat exchanger components. Laser beam brazing has an outstanding advantage: heat is applied only where it is needed to create bonds. The base material does not melt and the heat-affected zone becomes smaller, reducing the risk of mechanical distortion. Laser beam brazing has a disadvantage in terms of accessibility. In dense situations, the laser beam may fail to reach its target because the brazed joints may be hidden. Such “shadowing” means that the process cannot be carried out in ideal conditions, i.e., in the case of a circumferential seam, a full, uninterrupted circular movement may not be possible at an angle of incidence of 45 degrees. If steeper or flatter angles are chosen to achieve accessibility, this will result in uneven heating of the parts being joined, in this case the fin and the tube. The work presented shows the development of such brazing process. Firstly, it has to be established whether interruption and resumption of the laser brazing process will produce a usable result and further studies on heat distortion and process stability will be carried out to ensure the process is suitable for batch production.
3
Content available Laser cutting technology
EN
This paper presents the characteristics of the laser cutting process. Discussed are basic operating parameters of laser cutting devices and the advantages and disadvantages of this type of technology.
PL
W artykule przedstawiono wyniki badań technologii wykonywania złączy doczołowych rur dwuwarstwowych z gatunku 3R12/4L7, z płaskownikiem ze stali X6CrNi18-10, podczas symulacji wytwarzanie ściany gazoszczelnej (ściany szczelne) z wykorzystaniem technologii spawania hybrydowego laser + MIG/MAG, z materiałem dodatkowym w postaci spoiwa austenitycznego. Dobrano wstępne parametry spawania. Zaprezentowano wyniki badań metalograficznych makro- i mikroskopowych uzyskanych złączy oraz badania rozkładu twardości na przekroju poprzecznym złącza.
EN
The article presents the results of studies on a technology for producing butt joints of bimetallic pipes of grade 3R12/4L7 and at bars made of X6CrNi18-10 steel, simulating the fabrication of gas-tight walls, using hybrid laser + MIG/MAG welding with an austenitic filler material. The studies involved the selection of preliminary welding parameters. The results of macro- and microstructural metallographic examinations of joints are presented together with hardness distribution measurements across the joint cross-section.
EN
The famous Huygens – Fresnel principle can explain diffraction phenomenon in nature in which physics waves scattering appears as soon as these waves hit small objects, edges, and inhomogeneous environments. For optical areas, laser light diffractions are represented as subsidiary and main maxima in single slit interference. In geophysics topic, high frequency electromagnetic diffractions provide visible hyperbolae in the measurement sections. Moreover, seismic hyperbolic diffractions are also detected in the marine measured data. We researched the diffractions in the different physical waves by analyzing real data. Interpretation results illustrate characteristics of the wave sources in which their practical applications can be achieved. Modelled hyperbolae are used to check the matching with the real data. For real life examples, sizes of underground objects as water supplying pipes and wave propagation velocity in water can be calculated.
EN
The direct measurement method of AM-to-PM phenomena in fast silicon and InGaAs photodiodes is described. The setup is simple, relatively inexpensive and allows fast and precise measurements not only in a laboratory environment. During sample tests, the authors have found that the influence of bias voltage on the phase shift of an optical signal conversion is significant. The reported effect together with the influence of modulation depth on phase shift (AM-to-PM conversion) has a negative impact on an optical signal reception especially in coherent applications. The authors show that, with our proposed setups, it is possible to find optimal bias voltage and optimal optical power in order to reduce electrical phase noise of the photodetector.
PL
W pracy przedstawiono badania mające na celu określenie wpływu wartości posuwu lasera na chropowatość powierzchni przecinanej. Stwierdzono, że parametr ten ma istotny wpływ na badaną cechę wyrobu. Zwiększenie wartości posuwu wpływa na zmniejszenie chropowatości powierzchni przecięcia. Określono korelację między parametrem chropowatości Ra oraz wartością posuwu.
EN
In the paper investigated aimed at determining the influence of the laser displacement speed on the roughness of the cross-sectional surface were presented. It was found that this parameter has a significant influence on the tested characteristic of the product. An increase in the feed value reduces the roughness of the cutting surface. The correlation between the roughness parameter Ra and the feed value P was determined.
EN
The effect of laser etching on the surface properties of composite polyelectrolyte complex (PEC) based membranes as mixed matrix membranes was studied. The PECs were prepared by the stoichiometric mixing of cationic PDDA (poly(diallyl dimethyl ammonium chloride)) and anionic PSS (poly(sodium 4-styrene sulfonate)) as polyelectrolytes with various contents of ZIF-8 as filler. Composite membranes usually display improved bulk properties depending on the nature of the filler, but the surface properties are often dictated by the matrix covering the surface. The PEC composite membranes were then subjected to laser etching, resulting in the enhanced exposure of embedded ZIF-8 particles within the PEC structure in an attempt to improve the surface properties of the composite membrane. The crystal structure, morphology, and distribution of zinc at the PECs surface, before and after laser etching, were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS), respectively. In order to evaluate the improvement of the surface properties of the laser-etched membranes, a model experiment involving a catalytic reaction was chosen. The pristine and laser treated surfaces were tested for their catalytic activity for the transesterification of triglycerides present in soybean oil with methanol at a temperature of 150°C. Interestingly, the laser-etched PECs displayed substantially enhanced activity compared to the original composite PEC membranes as a result of surface erosion. These results could be interesting for the future development of composite membranes with improved surface properties where the filler needs to expose the surface of the membranes.
EN
The heating of a thin metal film subjected to the ultra-short laser pulse is presented. Mathe- matical description of this process is based on the system of equations describing the electron and lattice temperatures and dependences between intensity of heat fluxes and temperature gradients supplemented by appropriate boundary and initial conditions. In this approach, a system of four equations needs to be solved. In this paper, another method of solution of the above formulated problem is proposed. Using appropriate mathematical manipulations, instead of four equations, two equations describing the lattice and electron temperature dis- tributions are obtained. This system of two equations is solved using an implicit scheme of the finite difference method. The results obtained using both approaches were compared. They were almost identical, which confirms the correctness of the proposed method.
EN
The paper presents the analysis of neurobiological data on the existence of the structure of a parallel-hierarchical network. Discussed method of parallel-hierarchical transformation based on population coding and its application for the pattern recognition task. Based on the analysis, we can conclude that using the methods proposed, it is possible to measure the geometric parameters and properties of images, which can significantly increase the efficiency of processing, in particular estimating the center of mass based on moment characteristics. Experimental results demonstrate that due to various destabilizing factors, accurately measuring the energy center coordinates of laser beam spot images is challenging. However, training the PI network and classifying the fragments into "good" and "bad" can considerably enhance the accuracy of these measurements.
PL
W artykule przedstawiono analizę danych neurobiologicznych dotyczących istnienia struktury sieci równoległo-hierarchicznej. Omówiono metodę transformacji równoległo-hierarchicznej opartej na kodowaniu populacyjnym i jej zastosowanie do zadania rozpoznawania wzorców. Na podstawie przeprowadzonej analizy można stwierdzić, że za pomocą zaproponowanych metod można mierzyć parametry geometryczne i właściwości obrazów, co może znacznie zwiększyć wydajność przetwarzania, w szczególności szacowania środka masy na podstawie charakterystyki momentu. Wyniki eksperymentalne pokazują, że ze względu na różne czynniki destabilizujące, dokładny pomiar współrzędnych środka energii obrazów plamki wiązki laserowej jest trudny. Jednak szkolenie sieci PI i klasyfikowanie fragmentów na „dobre” i „złe” może znacznie zwiększyć dokładność tych pomiarów.
11
Content available remote Role of layer thickness on the damage mechanism in the LPBFed copper alloy
EN
Parts with interior voids created by the LPBF process are known to have the potential to cause fracture when subjected to mechanical loading. In this research, the key process parameters such as laser thickness (LT), scanning speed (SS), and laser power (LP) were taken into consideration to avoid the void formations which was the major reason for affecting the structural integrity. So, void formations (V), ultimate tensile strength (UTS) and reduced modulus (RM) were considered as the response parameters in this study. The entropy-associated weighted aggregated sum product assessment (WASPAS) approach was implemented to examine the favorable conditions which substantiated that the LT is the most influential parameter in nucleation of voids. The verification experiments prove that the void formation was reduced by 98.6% and the UTS and RM were enhanced by 52.17 and 31.7%.
12
Content available remote Technologie cięcia w produkcji kanałów wentylacyjnych z blach powlekanych
PL
W niniejszym artykule autorzy analizują technologie cięcia blach i taśm stalowych ocynkowanych wg PN-EN 10346:2015-09 [1] w gatunku DX51DZ275-M-A-C [2], o wydatku ocynku 275 g/m2. Wykorzystuje się je do produkcji różnego rodzaju kształtek wentylacyjnych prostokątnych i kanałów. Materiały o grubości w zakresie od 0,6 do 1,5 mm stosowane do produkcji muszą spełniać wymagania normy PN-89/H-92125.
EN
In this article, the authors analyse the technologies of cutting galvanized steel sheets and strips according to PN-EN 10346:2015-09 [1] in the grade DX51DZ275-M-A-C [2], with the galvanizing coating of 275 g/m2. They are used for the production of various types of rectangular ventilation fittings and ducts. Materials with a thickness in the range from 0.6 to 1.5 mm used for production must meet the requirements of the PN-89/H-92125 standard. The process of cutting, i.e. the loss of material consistency, consists in mechanical or thermal impact on the material until it is cut or burned through its entire thickness.
PL
Wzrost ilości informacji przesyłanych w ramach centrów danych i superkomputerów stymuluje rozwój i wykorzystanie dopasowanych do ich potrzeb oraz wymagań technik transmisyjnych. W referacie zostaną zaprezentowane techniki transmisji danych o wysokich przepływnościach wykorzystujące lasery VCSEL i światłowody wielomodowe.
EN
Growth of data transmitted within the data centers and supercomputers stimulates development of novel data transmission techniques adjusted to the data center needs. In the paper, ultra-high speed transmission techniques utilizing VCSEL laser and multimode fibres are presented.
EN
The work completed and discussed in this paper was to determine the level of smoke generation intensity in a selection of solid rocket propellants developed to minimise the level of generated smoke. This is an important issue for the application of the developed low-smoke propellant in, for example, the sustainer motor of a rocket missile. Reduced smoke generation levels can help to significantly reduce the feasibility of enemy detecting rocket munition launch sites. The authors of this paper developed a test stand that quantified the smoke generation intensity in rocket propellants. The test stand setup, based on the scatter of a laser beam by smoke, measured the smoke generation intensity, including during the operation of a rocket motor. A rocket micromotor was used along with a test chamber to measure the intensity of the smoke generated. It was located directly behind the motor exhaust and provided three laser- photodiode measurement channels. Tests of the smoke generated during the combustion of black powder and a standard mixture of HTPB and AP at a ratio of 20:80 provided reference baselines for the smoke generation intensity tests on the developed rocket propellants. The authors determined the smoke generation intensity of the propellants based on ADN, HTPB, and GAP with various additives. The results produced made it possible to compare the tested materials and select the most preferable materials as measured by their low smoke generation intensity.
PL
Przeprowadzone prace miały na celu określenie poziomu intensywności dymienia wybranych stałych, rakietowych materiałów pędnych, opracowanych przy założeniu minimalizacji generowanego przez nie dymu. Stanowi to istotne zagadnienie w kontekście zastosowania opracowanego materiału pędnego o zmniejszonym dymieniu, np. w silniku marszowym pocisku rakietowego. Ograniczenie wytwarzania dymu może znacząco zmniejszyć możliwości wykrycia miejsca startu środków bojowych przez przeciwnika. Autorzy artykułu opracowali stanowisko badawcze umożliwiające otrzymanie wskazań intensywności dymienia rakietowych materiałów pędnych. Przygotowany system, oparty na rozpraszaniu wiązki światła laserowego w dymie, umożliwia pomiar intensywności dymienia m.in. w warunkach pracy silnika rakietowego. Zastosowano mikrosilnik rakietowy wraz z komorą badawczą układu pomiaru dymienia, umieszczoną tuż za wylotem z mikrosilnika, wyposażoną w trzy tory pomiarowe laser- fotodioda. Pomiary generowanego dymu podczas spalania prochu czarnego oraz standardowej mieszaniny HTPB z AP w stosunku 20-80 stanowiły poziomy odniesienia do porównania intensywności dymienia opracowanych materiałów pędnych. Autorzy określili intensywność dymienia materiałów pędnych opartych na zastosowaniu ADN, HTPB lub GAP oraz różnych dodatków. Otrzymane rezultaty pozwalają na porównywanie przebadanych materiałów oraz wyselekcjonowanie najlepszych pod kątem niskiej intensywności dymienia.
PL
Narodowe Laboratorium Fotoniki i Technologii Kwantowych - NLPQT to projekt inwestycyjny, którego celem jest budowa infrastruktury pozwalającej na prowadzenie badań i prac badawczo-rozwojowych w zakresie technologii wykorzystujących światło i zjawiska kwantowe. Infrastruktura jest budowana przez zespoły badawcze pracujące w siedmiu polskich jednostkach naukowych. Po zakończeniu inwestycji będzie ona dostępna zarówno dla pracowników naukowych z innych ośrodków, jak i dla zainteresowanych przedsiębiorców działających w obszarze nowych technologii. W artykule przedstawiamy założenia dotyczące budowanej infrastruktury i opisujemy przykładowe stanowiska badawcze, których konstrukcja została już prawie ukończona.
EN
The National Laboratory of Photonics and Quantum Technologies - NLPQT is an investment project aimed at building an infrastructure that will allow research and development work in the field of technologies that use light and quantum phenomena. The infrastructure is built by research teams working in seven Polish research institutions. After the investment is completed, it will be available both to researchers from other research centers and to interested entrepreneurs operating in the field of new technologies. In the article, we present the assumptions regarding the NLPQT infrastructure and describe example research stations, the construction of which has already been almost completed.
EN
The Thomson parabola spectrometer (TPS) [1] is a well-known, universal diagnostic tool that is widely used in laser plasma experiments to measure the parameters of accelerated ions. In contrast to other popular ion diagnostics, such as semiconductor detectors or ion collectors, the TPS is not greatly affected by electromagnetic pulses generated during high-power laser interaction with matter and can be tuned to acquire data in various energy ranges of accelerated ions, depending on the goal of the experiment. Despite the many advantages of this diagnostic device, processing the collected data is a diffi cult task and requires a lot of caution during interpretation of gathered results. In this work, we introduce the basic principles of operation and data analysis based on the numerical tool created specifi cally for the TPS designed at the Institute of Plasma Physics and Laser Microfusion, present a range of data obtained during various recent experiments in which our TPS was used, and highlight the diffi culties in data analysis depending on the purpose of the experiment and the experimental setup.
EN
A contactless laser hygrometer based on light absorption by H2O molecules at 1392.5 nm is described. However, measurement results can be affected by optical noise when applied to an atmospheric tunnel or glass cuvette. The noises (occurring in the form of periodic fringes in the recorded spectrum) come from unexpected interference of the light beams reflected from surfaces of the windows or other optical elements. The method of their suppression is described in this article. It is based on wavelength modulation and signal averaging over the fringes period. Also, an experiment confirming the usefulness of this method is described here.
PL
Wykonywanie testów kontroli jakości obejmujących sprawdzenie zgodności wiązki lasera z osią wiązki promieniowania w systemie CyberKnife zalecane są zarówno przez samego producenta aparatu, jak i przez szereg organizacji, m.in. AAPM (ang. American Association of Physicists in Medicine), COMP (ang. Canadian Organization of Medical Physicists) oraz CPQR (ang. Canadian Partnership for Quality Radiotherapy). Zalecana częstotliwość wykonywania testu jest mocno zróżnicowana. Poprawne wykonanie testu, a co za tym idzie – prawidłowa kontrola zgodności wiązki lasera i osi wiązki promieniowania, pozwala zminimalizować wystąpienie błędów w pracy systemu CyberKnife, które mogą zmniejszyć dokładność pomiarów parametrów wiązki promieniowania oraz istotnie wpłynąć na realizację terapii. W prezentowanej pracy przedstawiono metodę weryfikacji zgodności wiązki lasera i osi wiązki promieniowania w oparciu o wykorzystanie filmów gafchromowych. Niezbędne w tej metodzie jest zapewnienie w trakcie pomiaru prostopadłości wiązki lasera względem podstawy, na której umieszczony jest film poddawany napromienianiu. Udaje się to osiągnąć, stosując kolimator typu pinhole. Napromieniony film poddawany jest analizie z wykorzystaniem oprogramowania ImageJ, które pozwala na wyznaczenie współrzędnych wiązki lasera i osi wiązki promieniowania, które służą dalej do obliczenia rozbieżności.
EN
Quality Assurance tests which checked the proper position of the laser centre and centre of the beam field are recommended by the vendor and world organizations like AAPM (ang. American Association of Physicists in Medicine), COMP (ang. Canadian Organization of Medical Physicists) or CPQR (ang. Canadian Partnership for Quality Radiotherapy). This type of test need to be performed monthly. Proper performing of this test and control of the working of the CyberKnife system is needed to be sure that all treatment plans are executed with high accuracy without any errors. The wrong position of those points can reduce the precision of the deposition dose and implicate different dose distributions in the patient’s body. This work presents the methodology of verification of the position of the laser and beam centre and the difference between those two points. This method is performed by using gafchromic films. One of the most important conditions is the parallel position of LINAC and the plastic plates where the gafchromic film will be positioned. To prepare the measurement system using of Pinhole cover plate is needed. Irradiated film in the next step is scanned and then analyzed in ImageJ, where the position of those points is measured and determines the distance between those points.
EN
A novel approach for studying the photo-thermal decomposition of HNS (2,2’,4,4’,6,6’-hexanitrostilbene) at 532 nm induced by a 10-nanosecond (ns) laser pulse is described. In this method, in-situ X-ray photoelectron spectrometer (XPS) - laser-quadrupole mass spectrometer on-line equipment was designed. New peaks at binding energies of 399.7 eV in the N 1s XPS spectrum and 288.6 eV in the C 1s spectrum showed that nitro-nitrite isomerization with subsequent release of NO occurs in the laser-induced decomposition of HNS. A new peak at 30 m/z in the mass spectrum is also associated with the mechanism of the nitro-nitrite isomerization of the HNS molecule, with subsequent release of NO. Quantum chemistry calculation results are in good agreement with the experimental results. We attribute this laser-induced decomposition as a photo-thermal decomposition for the high temperature rise due to the laser irradiation.
PL
W niniejszym artykule autorzy analizują technologie cięcia blach i taśm stalowych ocynkowanych wg PN-EN 10346:2015-09 [1] w gatunku DX51DZ275-M-A-C [2], o wydatku ocynku 275 g/m2. Wykorzystuje się je do produkcji różnego rodzaju kształtek wentylacyjnych prostokątnych i kanałów. Materiały o grubości w zakresie od 0,6 do 1,5 mm stosowane do produkcji muszą spełniać wymagania normy PN- -89/H-92125. Proces cięcia, czyli utraty spójności materiału, polega na mechanicznym lub cieplnym oddziaływaniu na materiał do momentu jego przecięcia lub przepalenia na całej jego grubości.
EN
In this article, the authors analyse the technologies of cutting galvanized steel sheets and strips according to PN-EN 10346:2015-09 [1] in the grade DX51DZ275-M-A-C [2], with the galvanizing coating of 275 g/m2. They are used for the production of various types of rectangular ventilation fittings and ducts. Materials with a thickness in the range from 0.6 to 1.5 mm used for production must meet the requirements of the PN-89/H-92125 standard. The process of cutting, i.e. the loss of material consistency, consists in mechanical or thermal impact on the material until it is cut or burned through its entire thickness.
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