Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "mechanical" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 1884
Tytuł:
Finite element analysis of mechanical stress in in-wheel motor
Autorzy:
Xu, Jie
Powiązania:
https://bibliotekanauki.pl/articles/2086692.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
deformation
in-wheel motor
mechanical loads
mechanical stress
Opis:
When the in-wheel motor is working, it will be affected by gravity, centrifugal force and electromagnetic force. These three kinds of mechanical loads will affect the mechanical stress characteristics of the in-wheel motor, and then affect the reliability of the in-wheel motor structure. In order to understand the influence of the above loads on the mechanical stress of the in-wheel motor, this paper takes a 15-kW built-in permanent magnet in-wheel motor as the research object. Based on the establishment of the electromagnetic field and structure field coupling analysis model of the in-wheel motor, the mechanical stress of the in-wheel motor under different mechanical loads under rated and peak conditions are calculated and analyzed, and the influence of different mechanical loads on the stress and deformation of the in-wheel motor are studied. The research results show that, regardless of the rated operating condition or the peak operating condition, the in-wheel motor has the largest mechanical stress and deformation under the combined action of centrifugal force and electromagnetic force, and the smallest mechanical stress and deformation under the action of gravity only; under the same load (except for the case of gravity only), the stress and deformation of the in-wheel motor under the peak operating condition are larger than those under the rated operating condition; and the maximum stress and deformation of the in-wheel motor appear at the rotor magnetic bridge and the inner edge of the rotor, respectively, so the rotor is an easily damaged part of the in-wheel motor.
Źródło:
Archives of Electrical Engineering; 2022, 71, 2; 455--469
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multifractal Nature of Diesel Engine Rattle Noise in Vehicle
Autorzy:
Puchalski, A.
Komorska, I.
Powiązania:
https://bibliotekanauki.pl/articles/176736.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical noise
mechanical vibration
multifractal formalism
alpha-stable distributions
Opis:
The investigation results of the emission of noises accompanying the diesel engine powertrain running in unloaded condition at low or idle speed, are presented in the hereby paper. The multifractal nature of the tested signals was confirmed by means of two groups of parameters. The proposed local parameters are based on the distribution of the probability density of measures, segregated into subsets according to pointwise Holder exponents. The obtained spectra constitute a set of multifractal measures related to singularities representing the local scaling of measures in various points of the time series. Global parameters were defined on the basis of multifractal measures of the parametrised Renyi’s entropy. These are properties treating summarily the whole spectrum of the emitted noise and reflecting changes of the vibroacoustic energy levels generated by noise sources. The tests encompassing simultaneous application of both groups of parameters confirmed their efficiency in the comparative analysis as well as in the subjective assessment of the noise level generated in the drive system of vehicles with diesel engines. This opens new possibilities within the simulation range of vehicle noises, for the needs of constructing the passive and active reduction systems of the effects of the vibroacoustic energy propagation.
Źródło:
Archives of Acoustics; 2017, 42, 3; 469-474
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Challenges of Using Elemental Nickel and Titanium Powders for the Fabrication of Monolithic NiTi Parts
Autorzy:
Farvizi, M.
Powiązania:
https://bibliotekanauki.pl/articles/958198.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot isostatic pressing
NiTi
mechanical alloying
microstructure
mechanical properties
Opis:
Due to its interesting properties and wide applications in different industries, fabrication of monolithic NiTi with cost-effective methods is an important and attractive issue. One of the economic ways to fabricate NiTi is employing elemental nickel and titanium powders. In this study, effects of using elemental powders as a precursor on the microstructure and mechanical properties of HIP-consolidated NiTi samples will be explored. The result of XRD analysis showed that after HIP process an interwoven structure which consists of NiTi2, Ni3Ti and B2-B19′ NiTi evolves. The formation of NiTi2/Ni3Ti intermetallics is thermodynamically favored which affects different aspects of this alloy: (i) it alters martensitic transformation temperatures; (ii) restricts essential properties of this alloy such as PE and SME, (iii) increases hardness, and (iv) yields to premature fracture at small strains during tensile tests.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1075-1079
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Polytetrafluorethylene on the Mechanical and Safety Properties of a Composite Modified Double Base Propellant
Autorzy:
Sun, S.
Zhang, T.
Zhao, B.
Zhang, G.
Li, X.
Luo, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358296.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
PTFE fibres
CMDB propellant
mechanical properties
mechanical sensitivity
combustion
Opis:
A novel Composite Modified Double Base (CMDB) propellant, formed by mechanically mixing aluminium/polytetrafluorethylene (Al/PTFE) powders, was prepared through a rolling process. A variety of tests, such as tensile properties, particle size analysis etc., were carried out to study the influence of PTFE on the CMDB propellant properties. The PTFE deformed from particles to fibres under a uniform shear force, forming a fibre network which greatly improved the propellant’s mechanical properties. Compared to that of the CMDB propellant without PTFE, the elongation of the propellant containing 6% PTFE was increased by 26 times, and moreover, the impact strength was enhanced by 326% at −40 °C. Significantly, the propellant friction and impact sensitivities were reduced by 75.8% and 35.6%, respectively. In addition, the presence of PTFE in the propellant resulted in fluorination of the Al. The gaseous combustion product AlF3 reduced the propellant combustion agglomeration. Consequently, PTFE significantly promoted the propellant’s mechanical performance, decreased the shock (friction, impact) sensitivity and reduced combustion agglomeration.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 468-484
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environment friendly polymeric materials - identification of their biodegradability on base of thermomechanical coupling phenomenon
Polimery przyjazne środowisku - identyfikacja ich biodegradawalności na podstawie efektów sprzężeń termomechanicznych
Autorzy:
Pieczyska, E. A.
Gadaj, S. P.
Nowacki, W. K.
Powiązania:
https://bibliotekanauki.pl/articles/281866.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
biodegradable polymers
tension test
mechanical characteristics
thermo-mechanical coupling
thermoelastic effect
Opis:
Environment friendly polymeric materials were investigated using an infrared camera in order to identify the relationship between their structure and properties including biodegradability. The experimental technique, based on the thermomechanical coupling phenomenon, was applied to investigation of polymers. Three samples of biodegradable polymers, i.e. the reference one and the modified two, were subjected to tensile and relaxation tests, according to a special program. The temperature changes were measured by a contact less method and related to mechanical characteristics. In the modified material, the temperature decrease, related to the thermoelastic effect, was observed in almost the whole range of the tensile tests. It means that the deformation does not exceed the limit of elasticity, and next, highelasticity - the stage of polymer deformation that follows the elasticity. The temperature measurements seem to be a useful tool for the investigation of biodegradable polymers: thermal characteristics may define a material according to its fragility related to biodegrability.
W pracy badano charakterystyki mechaniczne oraz efekty sprzężeń termomechanicznych w biodegradawalnych polimerach. Trzy rodzaje próbek polimeru, tzn. materiał odniesienia oraz modyfikowany w kierunku podwyższonej biodegradawalności, poddano badaniom rozciągania oraz badaniom relaksacyjnym. Temperaturę deformowanych próbek mierzono w sposób bezstykowy za pomocą kamery termowizyjnej. Stwierdzono, że odkształceniu materiału modyfikowanego aż do zerwania towarzyszy spadek temperatury zwany efektem termosprężystym. Oznacza to, że deformacja nie przekracza zakresu sprężystego i tzw. wysokoelastycznego, nieliniowego chociaż odwracalnego etapu występującego w procesie odkształcania polimerów. Pomiar temperatury może być przydatny do badań tych polimerów - charakterystyki temperaturowe pozwalają zidentyfikować kruchość materiału związaną z jego biodegradawalnością.
Źródło:
Journal of Theoretical and Applied Mechanics; 2004, 42, 4; 805-816
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of hardness on mechanical properties of elastomers
Autorzy:
Ochelski, S.
Bogusz, P.
Kiczko, A.
Powiązania:
https://bibliotekanauki.pl/articles/246003.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
experimental research
elastomers
mechanical properties
relative damping coefficient
mechanical loss angle
Opis:
In this paper, elastomers with different hardness factors were examined to evaluate the influence of the hardness on their mechanical properties. The following hardness numbers, measured in Shore A hardness scale, were investigated: 40; 60; 70 and 90°. Basic mechanical tests i.e. axial tension and axial compression have been performed in order to calculate elastic properties and stress values corresponding to the fixed strains: epsilon = 0.2; 0.3 and 0.5. The sigma (epsilon) dependences from the tension and compression tests are nonlinear and have different shapes. The tension plot can be described by a convex parabola, while the compression curve can be approximated by a concave one. dynamic load tests with loading freąuencies 0.01; 0.1; 1.0 and 3,OHz were performed in order to determine the hysteresis loop and to obtain force and displacement dependences in time. From those results the following factors were calculated: relative damping coefficient and mechanical loss angle, as well as their dependence on load frequencies. The influence of hardness on both in-phase and out-of-phase components of normal modulus were investigated. The sensitivity of the examined elastomers to the loading rate was also investigated.
Źródło:
Journal of KONES; 2010, 17, 1; 317-325
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Mechanical Properties of Naturally Aged Double Base Rocket Propellants
Autorzy:
Sućeska, M.
Matečić Mušanić, S.
Fiamengo, I.
Bakija, S.
Bakić, A.
Kodvanj, J.
Powiązania:
https://bibliotekanauki.pl/articles/357946.pdf
Data publikacji:
2010
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
mechanical properties
rocket propellant
natural ageing
dynamic mechanical analysis
tensile test
Opis:
Various chemical reactions and physical processes (such as stabilizer consumption, migration and evaporation of nitroglycerine, decomposition of nitroglycerine and nitrocellulose, etc.) take place in double based rocket propellants grains over the time, even under ambient storage conditions. The overall effect of these reactions and processes are changes of physical, chemical, thermal, ballistic and mechanical properties of rocket propellants with storage time, i.e. the reduction of the propellants performances and safe service life. The aim of this work was to evaluate the mechanical changes of rocket propellants – sustainers, built in in-service antitank guided missiles systems, induced by natural ageing at ambient conditions during up to 35 years of storage. The mechanical and viscoelastic properties were tested using a dynamic mechanical analyser, an uniaxial tensile and compression tester, and a notch toughness tester. The results have shown that the changes of the studied mechanical and viscoelastic properties are evident, although the results of the tests are rather scattered (as a consequence of measuring uncertainty, different ageing histories of propellants, etc.) or changes of some properties are not too pronounced. For example, after 15 years of storage at ambient conditions the glass transition temperature increases for about 5 C, the tan δ in the glass transition region decreases for about 5%, the storage and loss modulus at 25 °C increase for about 15%, Young modulus at 23 C increases up to 30%, the notch toughness at -30 C decreases up to 15%, etc. Along with these tests, the stabilizer content determination and proving ground ballistic tests were also done.
Źródło:
Central European Journal of Energetic Materials; 2010, 7, 1; 47-60
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Inverted Torsion Pendulum-Based Mechanical Spectrometer to Study Soft Matter
Autorzy:
Lei, M. L.
Chen, L.
Xiong, X. M.
Powiązania:
https://bibliotekanauki.pl/articles/351272.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
soft matter
mechanical spectrometer
inverted torsion pendulum
viscoelasticity
mechanical spectroscopy
viscosity
Opis:
A new multifunctional mechanical spectrometer is developed based on an inverted torsion pendulum showing high precision in a wide frequency range to study soft matter. Apart from measuring the internal friction of solids it can also be used to study viscoelasticity. In this report we describe basic principles of the novel instrument.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 1; 13-16
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the selected mechanical properties of the root parsley
Analiza wybranych właściwości mechanicznych pietruszki korzeniowej
Autorzy:
Gorzelany, J.
Matlok, N.
Kuzniar, P.
Zagula, G.
Powiązania:
https://bibliotekanauki.pl/articles/792352.pdf
Data publikacji:
2013
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
root parsley
mechanical property
chemical property
mechanical damage
destruction
Young's modulus
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2013, 13, 1
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of 3-D fracture criteria for assessment of fatigue strength of composite plate with internal delamination
Autorzy:
Romanowicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/242045.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aircraft engineering
mechanical engineering
Opis:
The fracture analysis of the composite plates with circular delaminations working in a regime of cyclic multi-axial stresses is the main object of the paper. Such structures with internal damage are mainly exposed for local or global buckling and delamination propagation under service loadings. Analyses of described phenomena are complex and require application of fracture mechanics and nonlinear analysis. The literature review of experimental and theoretical investigations of composite plates with circular delaminations is presented in the paper. The essential papers including experimental fatigue tests and theoretical techniques for studying of damage propagation growth are cited and crucial conclusions are given. In composite structures with internal delamination, the cyclic compression-tension and compression-compression stresses are the most dangerous. Moreover, the rapid increase of damage propagation occurs in the final stage of structure degradation. Such problem is investigated and illustrated on the example of rectangular plate with the circular delamination. The calculations are made for bi-axial compression and AS4/3501-6 graphite/epoxy material. The fracture analysis is made using different criteria based on the linear elastic fracture mechanics. The criteria are compared with the multiaxial experimental tests made for AS4/3501-6 graphite/epoxy material. It is observed that in composite plate with the internal delamination subjected for compressive loading the complex form of the gap opening occur. Because of this, the 3-D fracture criteria are applied in the investigations. Presented methodology allow for suitable selection of the multiaxial fracture model for analysis of such structures including interactions between different forms of the gap opening. The critical loadings for different layers orientation are estimated and given in the paper.
Źródło:
Journal of KONES; 2016, 23, 2; 301-308
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of dimensional proportions of cylindrical explosive on resulting blast wave
Autorzy:
Panowicz, R.
Trypolin, M.
Konarzewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/247380.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
materials engineering
mechanical engineering
Opis:
Explosives are broadly used today in many applications, both civilian and military. Many experiments involving explosives use either ball or cylinder charges. However, there can be raised a question whether an exact shape influences the resulting blast wave, and, additionally, if the length to diameter ratio of the cylinder influences the wave. To answer the question, numerical analysis was conducted. A 3D model of the charge was constructed in LS-Prepost software and calculated with use of an explicit FEM method in LS-DYNA software. To determine the change of character of the blast wave, the dimensions of the charge change, whereas the mass and distance from the centre of the charge are constant. Several length to diameter ratios was tested, starting from 0.25, to 2, in 0.25 increments. Two explosives, HMX and TNT, were used. As expected, the resulting Blast wave was different in each case, with 100% difference in pressure values between 0.25 and 2 L to D ratios, especially along the length axis of the cylinder. The results show that the exact diameters of the charges need to be taken into consideration while determining a type of charge to be used as well as determining the goal to be achieved during a particular conducted experiment.
Źródło:
Journal of KONES; 2016, 23, 4; 375-380
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-contact measurement of geometrical parameters in landing gear using the handheld 3D laser scanner
Autorzy:
Brewczyński, D.
Powiązania:
https://bibliotekanauki.pl/articles/242127.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aircraft engineering
mechanical engineering
Opis:
Laser 3D scanners are becoming widely used in many industrial branches. They can be used for prototyping, moulds' designs, special tools creation, reverse engineering, quality control. Also in medicine have been used in the generation of digital 3D files body parts or prosthetic. They are also used in diagnostics to analyse the wear of machine parts, deformation analysis of composite structures, creation of digital objects for FEA analysis. The article includes a description of the noncontact method of geometry measurement using handheld 3D laser scanner REVscan based on geometrical measurements of the MIG-29 aircraft landing gear example. During the analysis performed a complete scan of the landing gear with a resolution of 2 mm (accuracy of 0.05 mm) and a scan of critical points with a resolution of 0.2 mm (0.05 mm accuracy). Subsequently, an attempt to determine the position of characteristic points of connections is by editing the resulting cloud of points. During measurements has been shown the advantages, disadvantages and limitations in the use of non-contact method using 3D laser scanners. Collected data was used to find characteristic point of landing gear in main reference system. Two computer programs were used for data processing. First VXelements software is used to calibration, configuration of the scanner and collecting data. Second Geomagic 3D software allows extensive data processing.
Źródło:
Journal of KONES; 2014, 21, 3; 23-28
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical properties of sugar beet roots during harvest and storage
Autorzy:
Gorzelany, J.
Puchalski, C.
Powiązania:
https://bibliotekanauki.pl/articles/24107.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
deformation
root skin
mechanical harvesting
harvest
mechanical property
storage
root
sugar-beet
Źródło:
International Agrophysics; 2000, 14, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An influence of mechanical mixing and hot-pressing on properties of NiAl/Al2O3 composite
Wpływ mechanicznego mieszania oraz parametrów spiekania pod ciśnieniem na właściwości kompozytu NiAl/ Al2O3
Autorzy:
Kaliński, D.
Chmielewski, M.
Pietrzak, K.
Choręgiewicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/354230.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
materiały konstrukcyjne
mieszanie
kompozyty
intermetallics
composite materials
mechanical mixing
hot pressing
mechanical properties
Opis:
Intermetallic phases of the Ni-Al type belong to the group of modern constructional materials which have numerous advantageous properties such as high melting temperature, low density, high resistance to high-temperature oxidation (to about 1200 degree Celsjus), high mechanical strength, high fatigue strength, and high tensile and compressive strength (also at elevated temperatures). Intermetallic compounds have however also drawbacks in that they are quite brittle at room temperature which makes their mechanical processing very difficult and restricts their application range. These drawbacks can be obviated by modifying their chemical composition. Improving the properties of NiAl-based materials can be achieved by creating the composite with the matrix made of an intermetallic phase NiAl reinforced with ceramic (Al2O3) particles. This paper is concerned with the mechanical and physical properties (bending strength, fracture toughness, hardness, and Young modulus) and also the microstructure of NiAl/Al2O3 composite. The composite materials were produced by the hot-pressed method using the NiAl/20%Al2O3 (vol.%) powder mixtures. The composite thus produced had a high density of about 99% of the theoretical value and a high bending strength. The bending strength of the NiAl/20vol.%Al2O3 composite was higher by about 80% (635 MPa) than that of the pure NiAl phase (345 MPa). The experiments included also the examination of the effect of the rotational speed of the mill and the duration of the mixing process upon the size and distribution of grains, the microstructure, and phase composition of the composite powder mixtures obtained.
Fazy międzymetaliczne typu Ni-Al należą do grupy nowoczesnych materiałów konstrukcyjnych, charakteryzujących się m.in: wysoką temperaturą topnienia, niską gęstością, wysoką odpornością na utlenianie w wysokich temperaturach (do około 1200 stopni Celsjusza), wysokim modułem sprężystości- stabilnym ze wzrostem temperatury, wysoka wytrzymałością, wysoką odpornością na ścieranie, wysoką wytrzymałością zmęczeniową, wysoką wytrzymałością na rozciąganie i ściskanie (również w wysokich temperaturach). Związki międzymetaliczne mają jednak wady, są dość kruche w temperaturze pokojowej - co znacznie utrudnia m.in. ich obróbkę mechaniczną i zawęża zakres zastosowań. Jednym ze sposobów wyeliminowania tych wad jest modyfikacja ich składu chemicznego. Poprawę właściwości materiałów na bazie NiAl można osiągnąć m.in. poprzez wytworzenie kompozytu na osnowie NiAl umocnionego cząsteczkami Al2O3. W artykule zaprezentowano wyniki prac dotyczących opracowania warunków procesu mechanicznego mieszania mieszanin proszków związek międzymetaliczny (NiAl) - ceramika (Al2O3), a następnie ich spiekania. Przyjęte parametry mieszania i spiekania pozwoliły otrzymać kompozyt charakteryzujący sie odpowiednia gęstością, bliską teoretycznej (99.9%) oraz wysoką wytrzymałością. Wytrzymałość na zginanie kompozytu NiAl/20%obj.Al2O3 była o 80% (635 MPa) wyższą od wytrzymałości czystej fazy NiAl (345 MPa).
Źródło:
Archives of Metallurgy and Materials; 2012, 57, 3; 696-702
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low-Frequency Mechanical Spectroscopy of Lanthanum Cobaltite Based Mixed Conducting Oxides
Autorzy:
Wu, X. S.
Cao, J. F.
Chen, Z. J.
Liu, W.
Powiązania:
https://bibliotekanauki.pl/articles/355599.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mixed conducting oxides
mechanical properties
domain structure
phase transition
mechanical spectroscopy
internal friction
Opis:
The low-frequency mechanical spectra of lanthanum cobaltite based mixed conducting oxides have been measured using a computer-controlled inverted torsion pendulum. The results indicate that the internal friction spectra and shear modulus depend on the Sr doping contents (x). For undoped samples, no internal friction peak is observed. However, for La0.8Sr0.2CoO3-δ, three internal friction peaks (P2, P3 and P4) are observed. In addition to these peaks, two more peaks (P0 and P1) are observed in La0.6Sr0.4CoO3‒δ. The P0 and P1 peaks show characteristics of a phase transition, while the P2, P3 and P4 peaks are of relaxation-type. Our analysis suggests that the P0 peak is due to a phase separation and the P1 peak is related to the ferromagnetic–paramagnetic phase transition. The P2, P3 and P4 peaks are associated with the motion of domain walls. The formation of this kind of domain structure is a consequence of a transformation from the paraelastic cubic phase to the ferroelastic rhombohedral phase. With partial substitution of Fe for Co, only one peak is observed, which is discussed as a result of different microstructure.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1733-1738
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 1884

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies