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1
Content available remote Characteristics of titanium Grade 2 and evaluation of corrosion resistance
Klimas J., Łukaszewicz A., Szota M., Szota K.
Archives of Materials Science and Engineering
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2016
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Vol. 77, nr 2
65--71
EN
Purpose: The paper attempts to improve the properties of titanium Grade 2 by the use of the injection casting method with rapid cooling. Design/methodology/approach: Microstructural observations by using an optical microscope, microhardness studies, X-ray qualitative analysis as well as corrosion resistance tests were carried out. Corrosion resistance tests were conducted by measuring the open circuit potential and measuring the resistance to corrosion by the method of anodic polarization curves in a potential range close to the corrosion potential. Findings: Studies have shown that the application of the abovementioned preparation method affect the microstructure of the finished item. There has been a fragmentation of the structure and the formation of dendrites. Those changes have improved corrosion resistance and increase microhardness. There were no changes in the phase composition. Research limitations/implications: Studies were performed only in the Ringer's solution indicating a potential use of this material as a biomaterial. Further research should be conducted in more aggressive environments especially for the energy industry and chemical industry. Practical implications: The application of injection casting carries some complications, which mainly relate to quartz capillary where ingot is melted. Titanium as a reactive element strongly absorbs silicon out of the capillary causing changes in the chemical composition in the surface layer of the final element. The addition of silicon in the surface layer may affect on obtained results. Originality/value: Using the production method indicates its use in future in many industries.
2
Content available The temperature activation of carbon saturation steel process
Szota K.
Journal of Applied Mathematics and Computational Mechanics
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2014
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Vol. 13, nr 4
137--141
EN
The study presents the application of a mathematical description of a thermochemical process which consists in diffusion saturation of steel with carbon atoms. The mathematical description assumes temperature-based activation of the process of carburizing and estimates the effect of diffusion flow, which has a direct effect on the thickness of the obtained carburized layers, on the process temperature. The assumed model can be universal for all thermo-chemical processes of diffusion saturation of metallic materials.
3
Content available remote Thermal analysis of SF12050 high temperature superconducting tape
Jędryka J., Szota M., Nabiałek M., Szota K., Łukaszewicz A.
Archives of Materials Science and Engineering
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2014
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Vol. 69, nr 1
25--31
EN
Purpose: The paper deals with the determination of the impact and the possibility of heat treatment in order to improve the properties of YBa2Cu3O7-x- YBCO 2G HTS high-temperature superconducting tapes. Design/methodology/approach: Test samples of SF12050 superconducting tape, subjected to heat treatment - annealing in the temperature range of 450-1000°C. Two types of cooling were used on the air and with the furnace. Thus prepared samples were subjected to differential scanning calorimeter DSC - TG NETZSCH STA 409C.Results:The analysis was also subjected to the influence of temperature on the consistency of the protective layer with the other components of the tape, and a mechanism for destruction of the tape as a result of the impact of elevated temperatures. The paper also contains images of selected sections of the SF12050 superconducting tape which were preheated in the temperature range of 450-1000°C. Originality/value: Research carried out in the context of the article, made it possible to trace the influence of temperature on the destruction of superconducting tapes. Those studies show the destructive effects that may occur when using the type of tape, in particular as regards their application in the form of windings in transformers. Detailed knowledge of the thermal degradation mechanism of superconducting tapes, may lead to a response on how to modify them in order to avoid the devastating effect of temperature during operation.
4
Content available remote Determination of chemical composition and structure of YBa2Cu3O7-x – YBCO/Cu 2G HTS superconducting tape
Jędryka J., Szota M., Nabiałek M., Szota K., Łukaszewicz A.
Archives of Materials Science and Engineering
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2014
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Vol. 70, nr 1
14--20
EN
Purpose: The paper concerns the determination of the chemical composition and structure of high-temperature superconducting tapes YBa2Cu3O7-x– YBCO/Cu 2G HTS. Design/methodology/approach: Studies were carried outusing a scanning electron microscope with a chemical composition analyser on prepared samples of a tape. Moreover, an abrasion resistance test which shown resistance to friction at 1, 2 and 3 hours by using ball-tester was carried out. The individual layers which are components of the test tape and depths of wipes which appeared after test on ball-tester were evaluated. Findings: Studies showed a lot of information about abrasion resistance of tapes. Hourly friction, using ceramic ball did not result in breakthrough coating. The investigation are carried out for one, two and three hours. They also confirmed the chemical compositions provided by the manufacturer, as well as describe the individual layers of examined superconducting tapes. Originality/value: Detailed studies in particular, on wear resistance of superconductors, which relate to the chemical composition of the tapes, and their construction carried out in the context of the article, may be a prelude to further research into the production of superconducting tapes that will show much greater resistance to abrasion. The essence of the problem is a construction base, in particular during the installation of such tapes, for example in the form of a transformer winding.
5
Modelling the formation parameters in thin-film HTSC
Jeziorski L., Szota M., Nabiałek M., Lacki P., Jędryka J., Dośpiał M., Szota K.
Inżynieria Materiałowa
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2012
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Vol. 33, nr 6
569--572
EN
The paper presents an unconventional method of optimization the conditions for formation of the latest generation of high-temperature, superconducting tapes. In order to determine optimal conditions for formation process, the ADINA, was used. The performed numerical calculations based on the finite element method. Practical application of appropriate process parameters can reduce electrical losses occurring in the windings formed from the superconducting tapes and to obtain the maximum in transmission of power density. The results of numerical calculations have been verified empirically. In order to achieve empirical verification of results of the calculation, a device for determining the value of critical current in high-temperature superconducting tapes, was designed and built.
PL
W artykule zaprezentowano niekonwencjonalną metodę optymalizacji warunków formowania ostatniej generacji wysokotemperaturowych taśm nadprzewodzących. W celu określenia optymalnych warunków formowania zastosowano program ADINA. Wykonane obliczenia numeryczne oparto na metodzie elementów skończonych. Praktyczne zastosowanie prezentowanej metody umożliwia ograniczenie strat elektrycznych w formowanych taśmach nadprzewodzących oraz uzyskanie możliwości przesyłu maksymalnej mocy. Rezultaty obliczeń numerycznych zweryfikowano empirycznie. W celu empirycznej weryfikacji wyników numerycznych zaprojektowano i zbudowano układ do określania wartości prądów krytycznych nadprzewodników wysokotemperaturowych.
6
Content available Evaluation of the microstructure and magnetic properties of Fe73Me5Y3B19 (where Me = Ti or Nb) amorphous alloys
Nabiałek M., Pietrusiewicz P., Szota M., Dośpiał M., Jędryka J., Szota K., Lesz S.
Archives of Metallurgy and Materials
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2012
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Vol. 57, iss. 1
223-227
EN
The results of microstructure and magnetic properties studies of the amorphous Fe73Me5Y3B19 (where Me = Ti or Nb) alloys are presented The samples of the investigated alloys were produced in the form of ribbons with thickness of approximately 30 um by unidirectional cooling of the liquid material on a rotating copper wheel. Both investigated alloys, in the as-quenched state, were fully amorphous which was verified using a ‘Bruker’ X-ray diffractometer. Static hysteresis loops, measured using ‘LakeShore’ vibrating sample magnetometer (VSM), were typical as for soft magnetic ferromagnets. The Fe73Nb5Y3B19 and Fe73Ti5Y3B19 alloys were characterized by relatively high values of saturation of the magnetization (1.25 T and 1.26 T, respectively) and low coercivity field (16 A/m and 47 A/m, respectively). The core losses obtained for the investigated alloys were significantly lower than for commercially used FeSi transformer steels. Both alloys also exhibited excellent time and temperature stability of the magnetic properties (within the investigated temperature range), as confirmed by measurements of magnetic susceptibility and its disaccommodation.
PL
Celem pracy było zbadanie mikrostruktury oraz właściwości magnetycznych czteroskładnikowych stopów Fe73Me5Y3B19 (gdzie Me = Ti lub Nb) o strukturze amorficznej, otrzymanych techniką ultraszybkiego zestalania ciekłego stopu na miedzianym obracającym się bębnie. Strukturę odlanych taśm badano za pomocą dyfraktometru rentgenowskiego firmy "Bruker". Z pomiarów tych wynika, że obydwa czteroskładnikowe stopy w stanie po odlaniu były amorficzne. Statyczne pętle histerezy zmierzone przy użyciu magnetometru wibracyjnego (VSM) firmy "LeakeSchore", były typowe jak dla ferromagnetyków magnetycznie miękkich, a wytworzone stopy Fe73Nb5Y3B19 i Fe73Ti5Y3B19 cechowały się względnie wysoką magnetyzacją nasycenia (odpowiednio: 1.25 T i 1.26 T) i małym polem koercji (odpowiednio: 16 A/m i 47 A/m). Straty energii potrzebnej na jeden cykl przemagnesowania dla obydwu badanych stopów były znacznie mniejsze niż dla komercyjnie produkowanych stali transformatorowych FeSi. Wytworzone stopy wykazywały dobrą stabilność czasową oraz temperaturową właściwości magnetycznych (w wyznaczonym zakresie temperatur), któwą określono na podstawie pomiarów podatności magnetycznej i jej dezakomodacji.
7
Content available remote Determination of current characteristics of 2G HTSC
Szota K., Jędryka J., Nabiałek M., Szota M.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2011
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Vol. 10, nr 2
237-242
EN
This paper presents the results of investigations of a state-of-the art hightemperature ceramic superconducting tape of the SF 12050 series. The study focuses on the current and voltage characteristics, examination of the microstructure and analysis of the chemical composition in superconducting tapes of the SF series. In order to measure the current parameters, a measuring system was designed to investigate sections of the tapes at the temperature of liquid nitrogen. The system is powered with a direct current of parameters I = 0÷580 A and U = 0÷8 V. Measurements of the critical current were taken by means of determination of the decline in voltage along the measurement section for the tape with an accuracy of 1nV. Analysis of the chemical composition was carried out by using a scanning microscope which features a chemical composition microanalyser EDX. The paper presents microscopic images which are a result of the examination of the structures by means of a light microscope and scanning microscope. The method of preparation of the superconducting tapes for soldering and the method the selecting of solder were also presented.
8
Content available remote Percolation with a barier in finite systems
Drzewiński A., Klimek M., Kośmider M., Pasternak K., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2010
|
Vol. 9, nr 2
37-41
EN
The site percolation, where the long-range connectivity is the result of the occupancy probability defined on a site, is studied on the L×L square lattice. Method of determining of the location of the percolation pseudo-threshold pc(L) is proposed and the influence of a barrier on the percolation pseudo-threshold is analysed.
9
Porównanie struktur i parametrów prądowych wybranych taśm nadprzewodzących drugiego rodzaju
Szota M., Nabiałek M., Szota K., Jędryka J., Jeziorski L.
Inżynieria Materiałowa
|
2010
|
Vol. 31, nr 4
1245-1248
PL
W pracy przedstawiono porównanie struktur oraz charakterystyk prądowo- napięciowych wybranych wysokotemperaturowych taśm nadprzewodzących. W artykule zamieszczone zostały obrazy mikroskopowe nowej generacji nadprzewodników drugiego rodzaju, przedstawiające warstwowy układ nadprzewodników na podłożu stalowym lub niklowym. Do badań parametrów prądowych został zbudowany układ pomiarowy umożliwiający badanie odcinków taśm w temperaturze ciekłego azotu. Układ ten jest zasilany źródłem prądu stałego o parametrach I = 0÷580 A oraz U = 0÷8 V. Pomiary prądu krytycznego są wykonywane przez określenie spadku napięcia z dokładnością do 1 nV na odcinku pomiarowym nadprzewodnika. Przedstawiono również sposób przygotowania taśm do badań, oraz sposób lutowania taśm do układu pomiarowego co determinuje poprawność pomiarów.
EN
Structure and current characteristics of selected high temperature superconducting sheets is presented in this paper. Study of the microstructure of II type superconductors were performed. The superconducting layers were deposited on stainless steel or nickel substrates. A special cryogenic measurement system was built for investigation current parameters of superconducting wires sections. This system is powered from DC power supply with output 0÷8 V/0÷580 A. For investigation of current-voltage characteristic nano-voltmeter KTH 182 was used. It made possible measurements of voltage drop with precision 1 nV. A method of preparation of superconductors investigations was presented in the paper as well.
10
Content available remote Wetting for systems with an attractive effective interface potential
Drzewiński A., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2009
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Vol. 8, nr 2
43-46
EN
Effective Hamiltonian models for systems with attractive potentials predict the absence of the wetting transition for p < 3 (long-ranged wall-particle fields). Our numerical results based on the DMRG method that does not neglect the thermal fluctuations suggest more complex scenario.
11
Content available remote Bulk critical exponents in a presence of the capillary condensation
Drzewiński A., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2008
|
Vol. 7, nr 1
29-33
EN
The properties of a simple fluid or magnet with strong one-axis anisotropy can be studied by means of the Ising model. Such a model, but in an confined geometry with identical boundary fields, is studied along various thermodynamic paths using the density-matrix renormalization group technique. It has been found that also in the presence of the capillary condensation the critical exponent β of the bulk system can be found.
12
Content available remote Universality of the 2D wetting transition with respect to long-range forces
Drzewiński A., Parry A. O., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2007
|
Vol. 6, nr 1
57-63
EN
Effective Hamiltonian models predict non-universal critical singularities for two-dimensional wetting transitions with long-ranged forces. We verify these predictions by studying delocalization transitions in an infinitely long Ising strip, of width L (lattice spacings), with long-ranged surface fields that have opposite sign at each surface. The extrapolated asymptotic value for the exponent β:s does not confirm to the predicted non-universality but instead approaches the same universal value representative of systems with short-ranged forces. The crossover of the scaling behaviour of the transition lines is presented. Moreover, contrary to the existing predictions, the critical wetting transition for p = 2 has been found.
13
Content available remote Localization of the wetting transition for finite systems with a long-range wall-fluid potential
Drzewiński A., Parry A. O., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2006
|
Vol. 5, nr 1
15-22
EN
The properties of a simple fluid, or Ising magnet, confined in an Lx ∞ geometry, are studied by means of numerical density-matrix renormalization-group techniques. We have proposed and have verified a few criterions to determine the wetting transition phase boundary with different ranges of surface forces.
14
Content available remote Power laws in finite Ising systems
Drzewiński A., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2005
|
Vol. 4, nr 1
45-49
EN
The density-matrix renormalization-group method has been applied to infinite Ising strips of finite widths. In the presence of the small external magnetic field the infinite system critical power laws can be observed. The single power law describes the field dependence of the magnetization or the longitudinal correlation length only on the infinite system critical isotherm.
15
Content available remote Corrections to the Kelvin equation for long-range wall-particle potentials
Drzewiński A., Szota K.
Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej
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2004
|
Vol. 3, nr 1
31--39
EN
The properties of a simple fluid, or Ising magnet, confined in an L× ∞ geometry, are studied by means of numerical density-matrix renormalization-group techniques. Whereas the particle-particle potential is short ranged, the wall-particle potential is long ranged decaying as h1/lp for various values of p-integer, where l = 1,2,…,L labels the columns across the strip and h1 is the reduced amplitude of the boundary field. For the shortrange wall-particle potential, according to the Kelvin equation, the bulk coexistence field scales as 1/L for large L; thermodynamics and scaling arguments predict higher-order corrections of the 1/L2 and 1/L5/3 types at partial and complete wetting, respectively. However, at complete wetting for a large range of surface fields and temperatures a correction to scaling of type 1/L4/3 has been found recently. We discuss the influence of long-range wall-fluid potentials on the scaling. Results are obtained for several values of h1 for strips of widths up to L = 690.
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