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Search results for: ice phenomena
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Properties of surface layers of duplex stainless steel after burnishing processes
PublicationStress corrosion cracking resistance of cold worked layers of 25 Cr duplex stainless steel grade UR52N+ has been investigated. The surface layers were performed through burnishing treatment. The residual stresses at surface layers were determined using grazing angle incidence X-ray diffraction method (g-sin2 Ψ). Corrosion tests were performed with the use of Slow Strain Rate Test technique in boiling 35% MgCl2 solution. It has...
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Finishing of Ceramics in a Single-Disk Lapping Machine Configuration
PublicationPrzedstawiono metodę obróbki ceramiki technicznej na zmodifikowanej docierarce jednotarczowej z niezależnym napędem pierścienia prowadzącego. Omówiono przebieg obróbki z wykorzystaniem nowych narzędzi i zastosowaniem ziarna wiązanego.
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Cavitation wearing of the SUPERSTON alloy after laser treatment at cryogenic conditions
PublicationThe purpose of this paper is to demonstrate the method of laser remelting at cryogenic conditions of the SUPERSTON alloy and its influence on microstructure and cavitation wearing. The cavitation test was performed using the rotating disc facility in IPM PAN Gdansk. During the cavitation test, the mass loss of the material with different parameters of laser remelting was determined. Surface and cross-section microstructure of the...
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Research of hydrotronic variable displacement radial piston pump with electro -pneumatic control
PublicationThe paper presents the developed new electro-pneumatic control (pneumotronic) system for hydraulic fixed-displacement radial piston pump. Hydraulic fixed-displacement radial piston pump equipped with the proposed control system changes into hydrotronic variable-displacement radial piston pump. Pump flow rate control is realized by means of programmable logic controller, electro-pneumatic valves, pneumatic cylinders and a sensor.
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Redundantly Actuated 3RRR Parallel Planar Manipulator - Numerical Analyses of its Dynamics Sensitivity on Modifications of its Platform’s Inertia Parameters
PublicationIn the paper, numerical analyses, as well as dynamics of a complex mechanism, are presented. Two objectives are crucial for the paper: inverse dynamic model is needed (dedicated to be use in the model predictive controller); an identification method is searched (some trajectory parameters are controlled, when specific trajectory is tracked under an open-loop model-based control), as selected parameters must be identified for the...
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Comparison of Single and Multi-Population Evolutionary Algorithm for Path Planning in Navigation Situation
PublicationIn this paper a comparison of single and multi-population evolutionary algorithm is presented. Tested algorithms are used to determine close to optimal ship paths in collision avoidance situation. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. Principle of operation of single-population and multi-population evolutionary algorithm is described....
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Wear of Electroplated Tools Used for Flat Grinding of Ceramics
PublicationTwo methods for the abrasive properties evaluation, based on the image processing, are presented in the paper. Image processing analysis was developed to evaluate quickly the abrasive properties as the tool wears down. The coefficient based on the image brightness was calculated and additional analysis was based on the number of grains located on the active surface of the tool before and after machining. The active surfaces of...
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Surface Structure of Components Created by Stereolitography
PublicationStereolithography is an additive rapid prototyping method. This method is based on the principle of solidifying a liquid photopolymer (resin) by laser radiation. Models obtained with this method are characterized by a specific surface structure called “stairstep effect”. It causes that, the surface should be processed by additional finishing (postprocessing). To minimize the additional machining process, the model should be set...
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Research on Tool Temperature Dependence on Lapping Grains Size
PublicationCommonly used as a finishing operation, lapping has been used for achieving ultra-high finishes and close tolerances between mating pieces. Its carried out by applying loose abrasive grains between work and lap surfaces, and causing a relative motion between them resulting in a finish of multi-directional lay. The grains activity (sliding and rolling) in the working gap causes not only the material removal but also the temperature...
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The Influence of Workpiece Hardness on Plate Temperature during One Side Lapping
PublicationLapping leads to a surface with low roughness and high precision. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. The goal was to determine the correlation between the basic lapping conditions and wheel temperature. In work Bulsara et al. authors developed model to estimate the maximum and average temperature...
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A simplified model of 3-D pipe system conveying flowing liquid
PublicationThe paper presents a model reduction technique of a 3-D pipe system with flowing liquid. In the analysis and design of control (mechatronic) systems it is useful to work with simple, low order models. A hybrid reduced order model is proposed. The system model consists of two parts, the modal model and the finite element model.
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Influence of Flat Lapping Kinematics on Machinability of Ceramics
PublicationNew tools for flat grinding of ceramics are presented in the paper. Electroplated CBN tools (B64 and B107) were used in a modified single-disc lapping machine configuration. The results from experiments, such as the material removal rate and surface roughness parameters are presented and analyzed. Numerical simulations, based on the model for the shape error and tool wear estimation in machining with flat lapping kinematics, are...
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Technological Problems in Lapping on Flat Surfaces of Ceramic Parts
PublicationThis paper will present the results of research on single-disc lapping of flat surfaces of small ceramic elements. Machining with the use of different tools such as metallic, two-metallic and abrasive-metallic will be analyzed. The basics and techniques of reinforcement of laps will be discussed. The results of the influence of parameters on the surface quality of ceramic conponents (sealing) for three treatments on lapping machines...
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HILS for the Design of Three-Wheeled Mobile Platform Motion Surveillance System with a Use of Energy Performance Index
PublicationCurrent tendency in mechatronic design requires the use of comprehensive development of an environment, which gives the possibility to prototype, design, simulate and integrate with dedicated hardware. The paper discusses the Hardware-In-the-Loop Simulations (HILS) mechatronic technique, used during the design of the surveillance system based on energy performance index. The presented test configuration (physical controller – emulated...
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Modelling of Geared Multi-Rotor System
PublicationIn the paper the method of modelling a speed-varying geared rotor system is presented. The proposed approach enables us to obtain an accurate low-order lumped parameter representation of the investigated system. The final model consists of reduced modal models of an undamped beam/torsional shaft system as well as a spatially lumped model of other linear and nonlinear phenomena including gear mesh interaction.
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Generation of Optimal Process Plan Alternatives for Manufacturing Mechanical Components
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Application of Syntactic Pattern Recognition Approach in Design and Optimisation of Group Machining Systems
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The effect of pre-hydrogen charging on corrosion behaviour of superduplex stainless steel welded joints
PublicationThe paper presents results of research undertaken to determine the influence of hydrogen on passivity and corrosion resistance of 2507 super duplex stainless steel welded joints. Butt welded joints were made with low heat input using flux corded arc welding (FCAW) method. Coupons of 5.0 x 5.0 mm were cut from the welded joints containing weld metal (WM), heat affected zone (HAZ) and parent metal (PM). Hydrogen was introduced...
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Deformation of the Structural Details of the Components Created by the Rapid Prototyping Method
PublicationThe paper present the results of preliminary research and describes the deformation of construction details within the process of producing small element employing a stereography system. The article discuses a scheme for changes in data conversion. Variation in construction details have been described on the basis of analysing photographs.
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Hardened Steel Surface Waviness Created by Rolling Burnishing Process
PublicationThe surface of the finishing machined parts is defined mainly by roughness parameters. Growing demands on the part, especially mating sliding or rolling, require the specification of additional parameters, such as waviness parameters, particularly when there is significant resistance to seizing or noise reduction. This paper presents surface waviness characteristics of hardened burnished steel.
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The Roughness of the Hardened Steel Surface Created by the Rolling-Burnishing Process
PublicationBurnishing hard materials can be used as an alternative finishing process. this paper presents the results of burnishing hardened steel. The article discusses surface deformation that occurs during this process and depends on the selected parameters of the geometric structure of the force applied for surface burnishing.
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Wear and corrosion characteristics of the layers type (mn-p) formed on aluminium alloys
Publicationopisano multipleksową metodę wytwarzania warstw zawierających mangan i fosfor (mn-p) na stopach aluminium. przedstawiono wyniki badań mikrostruktury, właściwości tribologicznych i korozyjnych tych warstw. stwierdzono obecność tlenku manganu i fosforku manganu w wytworzonych warstwach oraz ich wysoką twardość, rzędu 1272 hv0,02. warstwy typu (mn-p) zmniejszają podatność stopu alsi13mg1cuni na korozję w 0,01 mh2so4.
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Indoor atmospheric degradation of historical metal objects studied by spectroscopic techniques
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Perovskites in Solid Oxide Fuel Cells
PublicationPrzeglądowa publikacja dotycząca wykorzystania ceramicznych materiałów perowskitowych w tlenkowych ogniwach paliwowych.
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Preparation and characterization of TiO2 nanostructures for catalytic CO2 photoconversion
PublicationThe titanium dioxide target (99.7%) of 1 cm in dia was ablated in vacuum by laser pulses(6 ns) at 266 nm and at repetition rate of 10 Hz. During deposition the laser fluence between 1 and 3.5 J/cm2 and the O2 pressure from the range of 10-2 - 1 Pa were applied. The thin TiO2 films were deposited on glass substrate (1 × 1 cm2) heated up to 500 °C. The chemical composition of the film and samples produced by annealing were investigated...
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Influence of spatial structures of 316L stainless steel on its cavitation erosion resistance
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Cavitation Erosion Resistance of Austenitic Stainless Steel after Glow-Discharge Nitriding Process
PublicationThis paper presents investigation of cavitation erosion resistance of nitrided austenitic stainless steel X5CrNi18-10. The diffusion layers were produced by using different parameters of atmosphere (N2:H2). The microstructure, chemical composition and phase identification of the modified layer were examined using scanning electron microscopy, glow-discharge optical emission spectrometer and X-ray diffractometry, respectively. Cavitation...
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Materials Design for the Titanium Scaffold Based Implant
PublicationThe main objective of here presented research is a design the scaffold/porous titanium(Ti) alloy based composite material demonstrating better biocompatibility, longer lifetime andbioactivity behaviour for load-bearing implants. The development of such material is proposed bymaking a number of consecutive tasks. Modelling the mechanical, biomechanical and biologicalbehavior of porous titanium structure and an elaboration of results...
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Optimization of Self-Organized TiO2 Nanotube Geometry on Ti and Ti Alloys Using Fuzzy Logic Reasoning
PublicationThe geometry of self-organized TiO2 nanotubes, obtained by electrochemicalanodization, has been determined by using fuzzy reasoning approach. The efficiency of TiO2nanotubular layer in biomedical applications depends on geometry and available surface area ofnanotubes, which can be determined by their diameter and length. The structure of nanotubesdepends on processing parameters of electrochemical anodization, like applied potential,anodization...
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Formation of High Corrosion Resistant Nanotubular Layers on TitaniumAlloy Ti13Nb13Zr
PublicationThis paper presents results of oxidation tests and corrosion investigations of titanium alloy Ti13Nb13Zr performed at different conditions. The oxide layers have been formed by electrochemical method in 2M H3PO4 + 0.3% HF solution for 30 min. and 1 h at 20 V constantvoltage. The corrosion tests have been made by potentiodynamic method in Ringer`s solution at pH ranged between 3 and 7. It has been shown that the nano-oxide films,...
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Effects of Laser Remelting at Cryogenic Conditions on Microstructure and Wear Resistance of the Ti6Al4V Alloy Applied in Medicine
PublicationThe titanium and its alloys can be subjected to surface treatment, including laser treatment. In this work a new laser treatment at cryogenic conditions of Ti6Al4V alloy has been described. The work has been aimed at establishing whether such surface treatment could be suitable for implants working under wear in biological corrosive environment. The remelting has been made with the use of CO2 continuous work laser at laser power...
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Environmental Degradation of Engineering Materials & Materials Engineering and Technologies
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Modelling of the Heat Flux Density Distribution for Laser Beam Welding
PublicationGreat interest of the laser beam welding in industry is a new theoretical task, making planning the welding procedure specification and the quality control of welded joints easier. Estimating and calculating the dimensions of a weld pool and temperature distribution near weld mainly concern heat source modelling. In the presented work calculations of welding pool shape and thermal field for cylindrical-powered-normally model of...
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Determination of Failure Causes of a Steam Turbine Casing
PublicationThe paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis;...
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The Effect of Welding Conditions on Diffusible Hydrogen Content in Deposited Metal
PublicationThe article presents the results of a literature survey and preliminary tests which set out effects of welding conditions on the amount of diffusible hydrogen in deposited metal. Experiments were conducted by using rutile coated electrodes which generate high contents of diffusible hydrogen in deposited metal. The amount of diffusible hydrogen was determined by a glycerin test.Eleven factors were considered: the electrode angle,...
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Degradation of Gel-Coat Layer in Glass/Polyester Laminate in Seawater Environment
PublicationGlass/polyester laminate coated with gelcoat layer of different thickness 0,5; 1,5; 3 mm was studied in terms of blistering behaviour and water sorption in hot water environment. Blistering was found to be accelerated for thin (0,5 mm) gel-coat layer compared to the thick (1,5; 3 mm), however no significant difference in blistering behaviour was observed between the laminates with gel-coat thickness 1,5 and 3 mm which may suggest...
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Formation of Porous Structure of the Metallic Materials Used on Bone Implants
PublicationResearch on improvement of structure and fabrication methods of the bone implants are carried out for many years. Research are aimed to shape the structures, that will have a Young's modulus value similar to the value of the human bones Young's modulus. Depending on theporosity, Young's moduli can even be tailored to match the modulus of bone closer than solid metals can, thus reducing the problems associated with stress shielding...
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Effect of crystallization process at cryogenic conditions on the functional properties of the SUPERSTON alloy used in production the ship's propellers
PublicationThe purpose of this paper is to show results of laser treatment at cryogenic conditions of the SUPERSTON alloy used for ship's propellers. That modification process ought to bring beneficial changes of microstructure and residual stresses in the surface layer. During the laser remelting at cryogenic conditions the microstructure changes significantly. This is related to synergistic effects of the solidification rate, phase transformations...
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Underwater Welding of Duplex Stainless Steel
PublicationThe present work was conducted to assess the weldability of duplex stainless steel at underwater conditions. Interest of underwater welding of this steel grade is connected with necessity of preparing welding repair technologies for subsea pipelines widely used in offshore oil and gas industry. The GMA local cavity welding method was used in the investigations. Welded beads were performed underwater at 0.5 m depth and in the air....
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Oxidation Time Influence on the Structure of the Cobalt Base Clad Layer and Scale Morphology
PublicationZbadano wpływ czasu utleniania na mikrosrukutręi własności mechaniczne a w szczególności mikrotwardość, warstw wykonanych ze stopu kobaltu.Warstwy były wykonane za pomocą napawania plazmowego (PTA). Stop kobaltu podlegał utlenianiu w powietrzu w temperaturze 800 topni celsjusza w czasie 1, 22 i 200 godzin. w wyniku utleniania nastapiło uformowanie warstw zgorzeliny oraz nastapiły zmiany w mikrostrukturze. Zaobserwowano także zmiany...
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The Influence of Modelling Material Zones on Strains and Stresses at Weld Toe Notch
PublicationThe latest development in the field of welding technology enabled prefabrication of thin-walled sandwich structures in an industrial scale. Sandwich structures fabricated of steel, or aluminium alloy plates and stiffeners are welded with the use of hi-power CO2 lasers. Strength analysis of such structures with the use of finite element method needs proper material modelling.In this paper the material model of steel sandwich panel...
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Multi Parameter Sliding Test Result Evaluation for The Selection of Material Pair for Wear Resistant Components of a Hydraulic motor Dedicated for Use With Environmentally Friendly Working Fluids
PublicationIn the paper the method and results are presented of the testing of tribological performance of a number of hard materials available commercially. The tests consisted in unidirectional sliding with liquid lubrication. The load and velocity regime chosen were similar to a standard four-ball lubricity test with constant velocity and load increasing over time. The regime was modified in such a way that over the initial part of the...
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Influence of Spatial Structures of 316L Stainless Steel on Its Cavitation Erosion Resistance
PublicationCavitation erosion performance of modified macroscopic internal structure 316L stainless steel was investigated. The samples processed by means of SLM method were subjected to cavitation erosion test. The scanning electron microscope Philips 30/ESEM was used to examine morphology of eroded surface.
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Effect of Some Sulphur Additives on The Degradation of 9Cr-1Mo Steel After Its 10 Years Service in The CCR Platforming Unit
PublicationThe work shows the results of the tests of 9Cr-1Mo steel, which was for 10 years operated in the CCR platforming unit in Group Lotos SA in Gdańsk, and then in the laboratory was sulphidised during 166 h at a temperature of 600 °C. Sulphidation was performed in a mixture of H2-H2S gases at the vapour pressure of sulphur 4.1·10-14 atm, so the order of magnitude of vapour pressure was less than that of the dissociation pressure of...
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Evaluation of Wear Resistance of Ti alloys used for elements friction of knee endoprosthesis
PublicationThe paper presents research results of resistance to abrasive wear of titanium alloys: Ti6Al4V (commonly used) and Til3Nb13Zr (alloy of new generation) in association with polyethylene (UHMW-PE) predisposed for elements on pair of the knee endoprosthesis. The results were analysed from the point of possibility of an use of new generation titanium alloys as components of such implants. The tests of resistance to abrasive wear of...
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Identification of the Inertia of Masses Flowing Water through the Pipes in Water Power Plants
PublicationW artykule przedstawiono sposób identyfikacji stałej czasowej reprezentującej bezwładność mas przepływającej wody w systemie rurociągów, w elektrowni wodnej. Przedstawiono strukturę modelu układu regulacji prędkości kątowej wykorzystywanego w procesie identyfikacji oraz przeprowadzono badania skuteczności działania metody w środowisku Matlab-Simulink. Opisano najistotniejsze wnioski wynikające z przeprowadzonych badań symulacyjnych.
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Selected problems of navigation of educational mobile robot
PublicationW artykule przedstawiono ideę sterowania układem autonomicznego robota mobilnego skonstruowanego do celów edukacyjnych. Opisano strukturę mechaniczną układu, układy sensorów oraz zakres możliwości wynikających z działania oprogramowania robota.
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The Behaviour Based Area Coverage of Unknown Environment by Autonomous Mobile Robot Using Modified ''The Way of the Ox'' Algorithm
PublicationPrzedstawiono propozycję rozwiązania zagadnienie całkowitego pokrycia terenu w układzie autonomicznego robota mobilnego. W tym celu zmodyfikowano algorytm "siewcy" oraz opracowano odpowiedni model układu, w środowisku Matlab-Simulink. Wykonano serię badań symulacyjnych, których najistotniejsze wyniki opisano w artykule.
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Localization of Mobile Robot Using Radio Waves
PublicationOpisano systemy lokalizacji robotów mobilnych wykorzystujące metody triangulacji i trilateracji, w przestrzeniach dwuwymiarowych. Zaproponowano metodę pomiaru odległości drogą radiową oraz przedstawiono uzyskane wyniki badań.
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Comparison the Accuracy of the Extrapolation Methods of the Time Phase Coincidence in Synchronization of Power Generating Units
PublicationW artykule opisano metody ekstrapolacji chwili zgodności fazowej napięć łączonych obiektów elektroenergetycznych. Przeprowadzono analizę porównawczą wybranych metod ekstrapolacji w równych warunkach pracy oraz przedstawiono najistotniejsze wyniki badań.