Wyniki wyszukiwania dla: AA2024 ALUMINUM ALLOY
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Pool Boiling of Water–Al2O3 and Water–Cu Nanofluids Outside Porous Coated Tubes
PublikacjaThis paper deals with pool boiling ofwater–Al2O3 and water–Cu nanofluids on porous coated, horizontal tubes. Commercially available stainless-steel tubes having 10 mm outside diameter and 0.6 mm wall thickness were used to fabricate a test heater. Aluminum porous coatings 0.15 mm thick with porosity of about 40% were produced by plasma spraying. A smooth tube served as a reference tube. The experiments were conducted under different...
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Probing Local Structural Changes by Sharp Luminescent Infrared Nanophosphor for Application in Light-Emitting Diodes
PublikacjaCr3+-doped infrared phosphors are promising candidates for next-generation phosphor-converted infrared light-emitting diodes (LEDs) because they can, in principle, tune and convert the luminescence spectra from an LED chip. However, most studies focus on broad-band Cr3+-doped phosphors, and the control mechanism of Cr3+-doped phosphors with sharp line emissions remains ambiguous. Here, we report LiGa5(1–x)Al5xO8:Cr3+ phosphors...
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Combined Long-Period Fiber Grating and Microcavity In-Line Mach–Zehnder Interferometer for Refractive Index Measurements with Limited Cross-Sensitivity
PublikacjaThis work discusses sensing properties of a long-period grating (LPG) and microcavity in-line Mach–Zehnder interferometer (µIMZI) when both are induced in the same single-mode optical fiber. LPGs were either etched or nanocoated with aluminum oxide (Al2O3) to increase its refractive index (RI) sensitivity up to ≈2000 and 9000 nm/RIU, respectively. The µIMZI was machined using a femtosecond laser as a cylindrical cavity (d = 60...
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High temperature corrosion of evaporator tubes with thermal sprayed coatings
PublikacjaDegradation examinations of outer surface of low-emission steam boiler evaporator tubes are presented in the paper. Metallographic evaluation of scale morphology, its micro sites chemical composition analysis and distribution of elements on cross sections have been performed. Water-wall tubes were exposed in steam boiler for up to two years period. Common tubes made of 16Mo3 steel suffered sulphide and molten salts corrosions....
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Effect of electrode waterproof coating on quality of underwater wet welded joints
PublikacjaIn this paper, the effects of different hydrophobic coatings on the surface of covered electrodes on the quality of wet welded carbon steel joints were discussed. Commonly available hydrophobic substances used in industrial applications were selected for the research. The aim of using waterproof coatings was to check the possibility to decreasing the susceptibility of highstrength low-alloy S460N steel to cold cracking. During...
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Austenitic stainless steel sensitization
Dane BadawczeHigh-alloy steels, thanks to their composition and content of appropriate alloying additives, are characterized by increased resistance to many corrosive environments. However, this is due to the increased sensitivity of the described construction materials to specific environmental conditions during their use. An example may be the increased susceptibility...
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Deposition and characterization of organic polymer thin films using a dielectric barrier discharge with different C2Hm/N2 (m = 2, 4, 6) gas mixtures
PublikacjaOrganic polymer thin films have been deposited on Si(100) and aluminum coated glass substrates by a dielectric barrier discharge (DBD) operated at medium pressure using different C2Hm/N2 (m = 2, 4, 6) gas mixtures. The deposited films were characterized by various spectroscopic techniques. Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) revealed the chemical functional groups present in the films. The surface...
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Operational problems of large power diesel engines combusting biofuels, considered togetherwith assessment of their operation
PublikacjaWithin this article the issue of large power self ignition engines fed with biofuels has been undertaken. The analysis focused mainly on operation problems. There has been noticed some advantages and difficulties associated with the biofuel application to self ignition engines. The research problem has been characterised and the research purposes have been proposed enabling the most profitable formation of energetic features of...
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Bioactive core material for porous load-bearing implants
PublikacjaSo far state of knowledge on biodegradable materials is reviewed. Among a variety of investigated materials, those composed of polymers and ceramics may be considered as only candidates for a core material in porous titanium alloy. The collagen and chitosan among natural polymers, polyhydroxy acids among synthetic polymers, and hydroxyapatite and tricalcium phosphate among ceramics are proposed for further research. Three essential...
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Manganese Phosphatizing Coatings: The Effects of Preparation Conditions on Surface Properties
PublikacjaManganese phosphate coating could be used to protect the surface of steel products. However, it is essential to determine the effects which process parameters, as well as the types of additives used, have on the efficiency of coating deposition. Thus, we present here a process of phosphatization of low-alloy steel (for 15 min at 95 ◦C) in manganese/nickel baths followed by a passivation process with the use of a silicon and zircon...
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The Influence of Selected Parameters of Numerical Modelling on Strains and Stresses at Weld Toe Notch
PublikacjaLatest development in the field of welding technology and prefabrication enabled massive production of thin-walled sandwich structures. Multi-layered sandwich structures are fabricated with the use of high-power CO2 lasers, friction welding, arc welding, hybrid welding, or other technique designed for the special purpose. Steel or aluminium alloy plates with thickness between 1 and 5 mm are connected by internal stiffeners. Strength...
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The Application of Cluster Analysis in the Assessment of the Weldability of Unalloyed Steels
PublikacjaNon-alloy steels constitute a large group of steels characterised by diversified chemical composition, structural morphology and a wide range of mechanical properties (determining weldability). The paper presents results of multidimensional analyses (based on cluster analysis) of 110 selected unalloyed steel grades. Properties adopted as diagnostic features included the chemical composition, mechanical properties (yield point)...
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The effect of elevated temperature on LCF damage growth in 2024AA – Experiment and modeling
PublikacjaThis paper presents the results of experimental low-cycle fatigue (LCF) tests conducted on EN-AW 2024 alloy in T3511 temper at 100 ◦C, 200 ◦C and 300 ◦C. The material’s basic fatigue characteristics were determined, such as fatigue life curve and cyclic strain curve. Both the hysteresis loop and nature of fracture surfaces obtained in macro- and microscopic observations (scanning electron microscope, SEM) were accounted for. The...
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Problems of analytical determination of journal bearing bush fatigue strength estimates
PublikacjaProblems connected with determination of stress distribution in sliding layer of thinwalled bearing bushes, investigated in bearing fatigue test rigs, have been presented. Using an example of plain bearings tested in the fatigue machine SMOK (built at the Gdask University of Technology) problems with obtaining a convergence of iterative procedure for determining the fatigue strength estimators of bearing alloy surface layer are...
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Fractal dimension for bending–torsion fatigue fracture characterisation
PublikacjaFracture surfaces after biaxial fatigue tests were compared using fractal dimension for three types of metallic materials in smooth and notched specimens made of S355J2 and 10HNAP steels and 2017-T4 aluminium alloy, considering both proportional and nonproportional cyclic loading. High-resolution optical 3D measurement studies were performed on the entire fracture surface. A direct correlation between fractal dimension and fatigue...
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Fractographic-fractal dimension correlation with crack initiation and fatigue life for notched aluminium alloys under bending load
PublikacjaIn this study, fatigue fracture surfaces of aluminium alloy 2017-T4 notched specimens were investigated under cyclic bending to find an alternative failure loading index.. The surface topographies were measured on the entire fracture area with an optical profilometer for different loading conditions. Fatigue crack initiation life Ni and total fatigue life Nf were examined using standard surface topography parameters (such as, root...
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Effect of particle size of aluminosilicate microspheres on the change of hydration heat of cement mortars and selected physical, chemical, and mechanical properties.
Dane BadawczeThis subject of the work is the study of selected properties of cement mortars containing two fractions of aluminosilicate microspheres with grain size in the range of 125 to 250 μm and from 250 to 500 μm. Mortar mixtures with ordinary Portland cement (OPC 42.5R) and three substitution rates of cement by microspheres, 1.5%, 3.5%, and 5.0%, were investigated....
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Wpływ stopowania laserowego z użyciem nanorurek węglowych stopu Ti13Nb13Zr do zastosowań biomedycznych na jego wybrane własności mechaniczne
PublikacjaDo eksperymentu użyto stopu tytanu Ti13Nb13Zr, który ze względu na swój skład chemiczny i właściwości mechaniczne stanowi materiał do zastosowań w inżynierii medycznej. Celem pracy była ocena wpływu stopowania laserowego stopu Ti13Nb13Zr z powłoką z wielościennych nanorurek węglowych na jego właściwości mechaniczne (chropowatość, nanotwardość, moduł Younga). Do wytworzenia powłoki węglowej wykorzystano metodę osadzania elektroforetycznego (EDP)....
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Imaging of morphological and physicochemical changes occuring in the structure of austenitic steel due to the thermal sensitization
Dane BadawczeIn polycrystalline materials, grain boundaries are always where phenomena such as surface diffusion, sedimentation and corrosion occur. They have a significant impact on the macroscopic properties of the construction material [1]. In addition to inhomogeneities such as manganese sulphide inclusions formed during the metallurgical process, interfacial...
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Designing a high-sensitivity dual-band nano-biosensor based on petahertz MTMs to provide a perfect absorber for early-stage non-melanoma skin cancer diagnostic
PublikacjaThe purpose of this study is development of a novel high-performance low-Petahertz (PHz) biosensor for non-melanoma skin cancer (NMSC) diagnosis. The presented device is designed to work within a microwave imaging regime, which is a promising alternative to conventional diagnostic methods such as visual examination, dermoscopy, and biopsy. The suggested biosensor incorporates a dual-band perfect absorber (operating bands at 0.909...
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Effect of Particle Size of Fly Ash Microspheres (FAMs) on the Selected Properties of Concrete
PublikacjaThis paper presents the investigations of selected properties of concrete containing two fractions of fly ash microspheres (FAMs) with grain size up to 200 μm and up to 500 μm. Concrete mixtures with ordinary Portland cement and three substitution rates of cement by FAMs, 1.3%, 2.0%, and 2.6%, were investigated. For all concrete mixes, the constant water–binder ratio (w/b) equal to 0.50 was used. The research program included the...
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Imaging of the effects of pitting corrosion with the use of AFM
Dane BadawczePitting corrosion is a local attack on a metal surface, limited to a point or small area, which appears as a hole. Pitting corrosion is one of the most harmful forms of corrosion due to the fact that it is associated with small, difficult to detect damage, that can even lead to perforation of the structure. A single pit may range in size from micrometers...
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Hydrogen degradation of pre-oxidized zirconium alloys
PublikacjaThe presence of the oxide layers on Zr alloys may retard or enhance the hydrogen entry and material degradation, depending on the layer features. This research has been aimed to determine the effects of pre-oxidation of the Zircaloy-2 alloy at a different temperature on hydrogen degradation. The specimens were oxidised in laboratory air at 350°C, 700°C, and 900°C. After, some samples were tensed at 10-5 strain rate and simultaneously...
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Multisine impedimetric monitoring with an in-depth distribution of relaxation times analysis of WE43 and AZ31 magnesium alloys corrosion
PublikacjaThis research aims to develop and utilize an impedance-based tool for monitoring non-stationary electrochemical processes, coupling the multisinusoidal perturbation signal approach and distribution of relaxation times (DRT) analysis for the first time. The approach was used to distinguish independent processes occurring at the surface of AZ31 and WE43 Mg alloys undergoing corrosion in Hank’s Balanced Salt Solution at 37 °C. We...
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The Influence of Modelling Material Zones on Strains and Stresses at Weld Toe Notch
PublikacjaThe 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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Evaluation of reformer tubes degradation after long term operation
PublikacjaPurpose of this paper is to show the effect of long-term service at elevated temperatures on microstructural changes of cast steel reformer tubes made of the alloy IN-519 (24%Cr, 24%Ni, Nb). The relationship between mechanical properties and microstructure degradation is discussed. Investigations were performed on five tubes taken from ammonia reformer furnace. Tubes worked at temperature of 880C and 3,2 MPa pressure. The operation...
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Effect of Laser Treatment on Intrinsic Mechanical Stresses in Titanium and Some of Its Alloys
PublikacjaLaser surface treatment conducted at different power levels is an option to modify titanium bone implants to produce nano- and microtopography. However, such processing can lead to excess mechanical stress within the surface layer. This research aims to calculate the level of such residual stresses after the surface processing of Ti grade IV, Ti15Mo, and Ti6Al7Nb alloys with an Nd:YAG laser. Light and scanning electron microscopies...
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Evaluation of the Cathodic Electrodeposition Effectiveness of the Hydroxyapatite Layer Used in Surface Modification of Ti6Al4V-Based Biomaterials
PublikacjaThe important issue associated with the design and the fabrication of the titanium and titanium alloy implants is the increase of their biointegration with bone tissue. In the presented paper, the research results concerning the conditions used in the cathodic deposition of hydroxyapatite on the surface Ti6Al4V substrates primarily modified by the production of TiO2 nanoporous coatings, TiO2 nanofibers, and titanate coatings, are...
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Recent advances in electrochemically surface treated titanium and its alloys for biomedical applications: A review of anodic and plasma electrolytic oxidation methods
PublikacjaNowadays, titanium and its alloys are widely used materials in implantology. Nevertheless, the greatest challenge is still its appropriate surface treatment in order to induce optimal properties, which facilitates formation of a permanent bond between the implant and human tissue. The use of electrochemical treatment such as anodic oxidation or plasma electrolytic oxidation allows for the production of porous coating that mimics...
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The Antibacterial and Antifungal Textile Properties Functionalized by Bimetallic Nanoparticles of Ag/Cu with Different Structures
PublikacjaWe reported a preparation and characterization of five kinds of impregnation solutions, containing Ag/Cu in the formof bimetallic nanoparticles (alloy and core-shell) as well as ionic species. The cotton-polyester textiles were successfully impregnated during the washing and ironing process by as-prepared solutions to have antibacterial and antifungal properties against to Escherichia coli, Staphylococcus aureus, and Candida albicans....
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Weldability of Underwater Wet-Welded HSLA Steel: Effects of Electrode Hydrophobic Coatings
PublikacjaThe paper presents the effects of waterproof coatings use to cover electrodes on the weldability of high-strength, low-alloy (HSLA) steel in water. With the aim of improving the weldability of S460N HSLA steel in water, modifications of welding filler material were chosen. The surfaces of electrodes were covered by different hydrophobic substances. The aim of the controlled thermal severity (CTS) test was to check the influence...
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Application of Shape Memory Alloys in Pipeline Couplings for Shipbuilding
PublikacjaThe aim of the study is to analyse shape memory alloy (SMA) pipeline joints in limited space applications for all kinds of ships. Generally, the space available in various areas on ships is strictly limited and service works usually meet many obstacles. If we consider a pipeline, the flange joints always require a larger free space around the pipe than the pipe alone. A simultaneous problem can occur with the propeller shaft line...
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Effect of composition on the thermal properties and structure of M-Al-Si-O-N glasses, M = Na, Mg, Ca
PublikacjaThe primary objective of this study is to explore the relationship between the composition, structure, and thermal characteristics of M-Al-Si-O-N glasses, with M representing sodium (Na), magnesium (Mg), or calcium (Ca). The glasses were prepared by melting in a quartz crucible at 1650 °C and AlN precursor (powder) was utilized as a nitrogen source. The measured thermal properties studied were glass transition temperature (Tg),...
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API 5L X65 steel - tensile properties in room temperature -10°C, along rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - CMOD-force record in -10°C, along rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - tensile properties in room temperature +20°C, across rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - tensile properties in room temperature -10°C, across rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - CMOD-force record in -10°C, across rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - tensile properties in room temperature +20°C, along rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - fracture documentation of CMOD-force test in -10°C, along rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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API 5L X65 steel - fracture documentation of CMOD-force test in -10°C, across rolling direction
Dane BadawczeSteel designated as API 5L X65 is often used for oil and gas transportation pipelines. It is caused due to its high ductility, weldability and good corrosion resistance. API 5L X65 is a low alloy steel with carbon content less than 0.3% (depends on delivery condition). Once installed, a pipeline remains in place for many years. Throughout its life,...
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Nanostructures fabrication with use of electrical AFM litography
Dane BadawczeIn the last 10 years, one of the nanotechnological trends has been observed, consisting in the development of new variants of computer memory systems with high capacity and speed of access, using quantum dots. One of the techniques for creating nanodots and other nanostructures is based on the use of an atomic force microscope acting as a lithographic...
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Influence of Surface Laser Treatment on Mechanical Properties and Residual Stresses of Titanium and its Alloys
PublikacjaSurface modification of the titanium and its alloys used in implantology with a long-pulse laser can change the surface topography, but it also leads to changes in the stress sign and magnitude in the resulting subsurface layer. The presented research was aimed at evaluating the state of stress after laser remelting with the Nd:YAG laser of pre-etched titanium alloys Ti6Al4V and Ti13Nb13Zr and pure titanium. The obtained surface...
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Preparation and characterization of Pt/Pd-modified titanium dioxidenanoparticles for visible light irradiation
PublikacjaSeries of Pt/Pd–TiO2photocatalysts were obtained using the sol–gel method. The Pt/Pd–TiO2nanocom-posites showed significant visible light photoactivity. X-ray diffraction, STEM microscopy, UV–visspectroscopy and BET characterization allowed to conclude that the photocatalysts at the best perfor-mance had the anatase structure, 91 m2/g specific surface area, Pt/Pd alloy structure and 1–4 nm particlesize. The photocatalytic activity...
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Effect of TiO2 Concentration on Microstructure and Properties of Composite Cu–Sn–TiO2 Coatings Obtained by Electrodeposition
PublikacjaIn this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath containing 0–10 g/L of TiO2 nanoparticles. The effect of TiO2 particles on kinetics of cathodic electrodeposition has been studied by linear sweep voltammetry and chronopotentiometry. As compared to the Cu–Sn alloy, the Cu–Sn–TiO2 composite coatings show rougher surfaces with TiO2 agglomerates embedded in the metal matrix. The highest...
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Effect of double thermal and electrochemical oxidation on titanium alloys for medical applications
PublikacjaThe research focuses on the development and characterization of innovative thin hybrid oxide coatings obtained in subsequent processes of thermal (TO) and electrochemical (EO) oxidation. Four different surface modifications were investigated and the microstructure was determined, the mechanical, chemical and biological properties of the Ti-13Nb-13Zr alloy were assessed using scanning electron microscopy, X-ray dispersion analysis,...
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Fatigue Bending of V-Notched Cold-Sprayed FeCoCrNiMn Coatings
PublikacjaCold-spray coatings were produced by FeCoCrNiMn high-entropy alloy powders deposited on carbon steel substrate. The coatings were realized at intermediate temperature and high pressure (at 1100 °C and 7 MPa). The coating microstructure was characterized by scanning electron microscopy and X-ray diffraction, revealing a very dense deposition and high flattening ratio of the splatted particles. This had a large influence on the...
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Dissimilar underwater wet welding of HSLA steels
PublikacjaThe high-strength low-alloy S460ML and S460N steels were chosen for underwater wet welding of dissimilar T-joints using covered electrodes. For improving the quality of joints, the temper bead welding (TBW) method was used. The application of TBW in pad welding conditions has been investigated earlier but the possibility of usage of this technique in welded joints was not analyzed. The main aim of the study was to check the influence...
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Electrophoretic Deposition and Characteristics of Chitosan–Nanosilver Composite Coatings on a Nanotubular TiO2 Layer
PublikacjaThe surface treatment of titanium implants has been applied mainly to increase surface bioactivity and, more recently, to introduce antibacterial properties. To this end, composite coatings have been investigated, particularly those based on hydroxyapatite. The present research was aimed at the development of another coating type, chitosan–nanosilver, deposited on a Ti13Zr13Nb alloy. The research comprised characterization of the...
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Up-conversion white emission and other luminescence properties of a YAG:Yb2O3·Tm2O3·Ho2O3@SiO2 glass-nanocomposite
PublikacjaWe report on a glass-nanocomposite material consisting of yttrium aluminum garnet (Y3Al5O12, YAG) nanocrystals co-doped with Yb3+, Tm3+ and Ho3+ ions as well as entrapped into a SiO2 xerogel. This 94YAG·5Yb2O3·0.8Tm2O3·0.2Ho2O3@SiO2 (abbr. YAG:YbTmHo@SiO2) nanocomposite material has been prepared by sol–gel procedure. Its structure and morphology has been characterized by means of X-ray diffraction (XRD) and scanning electron microscope...