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Tytuł:
Synthesis and Thermal and Textural Characterization of Aniline Formaldehyde-Organoclay Composites
Autorzy:
Gürses, A.
Eroğlu, Z.
Güneş, K.
Doğar, Ç.
Powiązania:
https://bibliotekanauki.pl/articles/1187414.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
Opis:
In this study, the synthesis of aniline-formaldehyde resin, and its thermal and structural characterization, as well as the preparation and characterization of the resin-organoclay composites were carried out. For this, first, at 70°C and acidic conditions the aniline formaldehyde prepolymer was prepared and then cured at 120°C under vacuum. The structural and thermal characterization of the resin was made using FTIR and DSC techniques. By using the Cetyltrimethylammonium Bromide modified Montmorillonite (OMMT) and the synthesized resin, the resin-organoclay composites were prepared by melt intercalation method. Characterization of the resin-organoclay composites prepared with the different ratios of organoclay is made with the same techniques. The FTIR and thermal analysis results of the composites indicate that a cross-linked polymeric matrix was formed. The thermal behavior of the composites has also significantly changed compared to pure resin.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 853-856
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of Surfactant-Modified Powder Activated Carbon (SM-PAC) Reinforced Poly (Ethylene Oxide) (PEO) Composites
Autorzy:
Gürses, A.
Ejder-Korucu, M.
Doğar, Ç.
Powiązania:
https://bibliotekanauki.pl/articles/1398798.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
Opis:
Poly (ethylene oxide), PEO, which was used for a wide variety of applications is a flexible, crystalline, thermoplastic, water-soluble and non-ionic polymer. The most of studies on surfactant-modified activated carbon (SM-PAC) have been generally focused on the removal of contaminants. This study aims the preparation of PEO/(SM-PAC) composites, using solution-intercalation method. Firstly activated carbon was modified with cationic surfactant, Cetyltrimethylammonium Bromide (CTAB). Then PEO/(SM-PAC) composites were prepared using solution-intercalation method, with two different (SM-PAC) contents (1.0 and 2.0 wt.%). The characterization of the composites was made by X-ray diffraction (XRD), Fourier Infrared Spectroscopy (FT-IR), thermal analysis and tensile tests. The XRD patterns revealed that 2θ positions of the broad peaks belonging to the composites significantly shift to left compared with those of virgin PEO. The SEM images of the surfactant-modified powdered activated carbon (SM-PAC)/PEO composites prepared with the two different SM-PAC contents show that there is an intensive interaction between the CTA^{+} ions of modified activated carbon surface and the polymer chains. From the tensile tests, it was found that the unmodified powdered activated carbon dispersed into the polymer matrix made the ductile polymer more brittle. However, the tensile and yield strengths of the composite, prepared with modified powdered activated carbon, have decreased, and the strain percent value has significantly increased.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 849-852
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical and Thermal Properties of Pumice Powder Filled PPS Composites
Autorzy:
Sahin, A.
Yildiran, Y.
Avcu, E.
Fidan, S.
Sinmazcelik, T.
Powiązania:
https://bibliotekanauki.pl/articles/1182862.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Qk
81.70.Bt
81.70.Pg
Opis:
Recently, it is common application to use particle materials as fillers to improve engineering properties and lower the cost of finished product. Pumice powder is cheaper than most of traditional particle fillers, however use of pumice powders as a reinforcing material in composites has not been studied in literature. Hence, in this study we have investigated the mechanical and the thermal properties of pumice powder filled polyphenylenesulphide (PPS) composites. PPS composites were reinforced with pumice powder at different loading rates (0, 1, 3.5, and 10 wt%) and they were manufactured by twin screw extruder and injection molding machine. Thermal properties were investigated by thermogravimetric analysis and differential scanning calorimeter methods. Moreover, mechanical properties such as barcol hardness, tensile strength, and modulus of samples were investigated. Thermal properties of composite samples have varied significantly depending on the loading rate. Also mechanical properties of pumice powder filled PPS composites have showed better results than pure PPS. According to test results both of mechanical and thermal properties of composites have improved with pumice powder reinforcement and it is determined that pumice powders can be used instead of traditional particle fillers.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 518-520
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism and Kinetics of Precipitation and Dissolution of GP Zone and Metastable Phase in Al-3wt% Cu Alloy
Autorzy:
Khamel, B.
Sahnoune, F.
Fatmi, M.
Brihi, N.
Powiązania:
https://bibliotekanauki.pl/articles/1033403.pdf
Data publikacji:
2017-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.30.Mh
81.70.Pg
81.30.Bx
Opis:
Thermal analysis techniques remain important tools amongst the large variety of methods used for analysis of the precipitation and dissolution of the Guinier-Preston zone and metastable phase θ' in Al-3wt% Cu. In the present study, the kinetics of precipitation and dissolution of the Guinier-Preston zone and metastable phase θ' in Al-3wt% Cu was investigated using differential scanning calorimetry carried out between room temperature and 430°C at heating rates of 20, 25, and 30°C min¯¹. The activation energies evaluated through isothermal differential scanning calorimetry treatment using the Johnson-Mehl-Avrami theory were 25, 100, and 80 kJ mol¯¹ for the Guinier-Preston zone precipitation, formation of θ'/θ and dissolution of θ', respectively. The Avrami constant n obtained by the Ligero method was about 1.5 for the formation of θ'/θ indicating that bulk nucleation is dominant in θ'/θ formation controlled by diffusion from a constant number of nuclei.
Źródło:
Acta Physica Polonica A; 2017, 131, 1; 133-135
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transformation and Sintering of Algeria Clay Powder
Autorzy:
Beddiar, L.
Sahnoune, F.
Heraiz, M.
Redaoui, D.
Powiązania:
https://bibliotekanauki.pl/articles/1033574.pdf
Data publikacji:
2017-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Mh
81.70.Pg
81.30.Mh
Opis:
Clay is one of the most used natural materials in the ceramic industry with various applications such as pottery, tiles, cement and bricks. The latter are used as a building material because of their excellent thermal and mechanical properties. In the present study, Algerian clay from Al-maathed area, M'sila district, was used to prepare bricks. The chemical composition of the clay was determined using X-ray fluorescence. Firing of clay was carried out in the temperature range 20-1000°C, at different heating rates. The present phases and their transformations, the activation energy, and the sintering mechanism were evaluated using X-ray diffraction, differential thermal analysis, thermogravimetric analysis and dilatometry. The activation energy for the sintering mechanism obtained from non-isothermal treatments is 420 kJ/mol. The value of the Avrami exponent, n, is determined from the shape of the crystallization exothermic dependence. It is related to m parameter (a numerical factor which depends on the dimensionality of crystal growth) obtained by Matusita method. Both of which are about 1.2 for clay sintering. These values indicate that bulk nucleation is dominant in clay sintering by three-dimensional growth, with polyhedron-like morphology controlled by interface reaction.
Źródło:
Acta Physica Polonica A; 2017, 131, 3; 566-568
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Kinetics of Spinel Formation of Algerian Halloysite by Differential Thermal Analysis
Autorzy:
Heraiz, M.
Sahnoune, F.
Belhouchet, H.
Raghdi, A.
Ouali, A.
Powiązania:
https://bibliotekanauki.pl/articles/1033398.pdf
Data publikacji:
2017-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
81.20.Ev
82.20.-w
Opis:
The kinetics of spinel (Al-Si) crystallization from Algerian halloysite (DD1) was investigated using differential thermal analysis. Experiments were carried out on samples between room temperature and 1400°C with constant heating rate from 2 to 20°C min¯¹. The activation energies measured from isothermal and non-isothermal treatments were 1054.85 and 1140 kJ mol¯¹, respectively, for the spinel (Al-Si) formation. The Avrami constant n obtained by the Ligero method and the m parameter obtained by the Matusita method were about 2 for spinel crystallization. This value indicates that the crystallization mechanism of Al-Si spinel phase proceeds by bulk nucleation of the phase formation with a constant number of nuclei and that the three-dimensional growth of crystals is controlled by diffusion.
Źródło:
Acta Physica Polonica A; 2017, 131, 1; 139-142
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation and Structure of Nanocrystalline Al-Mm-Ni-Cu Alloys
Autorzy:
Latuch, J.
Krasnowski, M.
Ciesielska, B.
Powiązania:
https://bibliotekanauki.pl/articles/2035467.pdf
Data publikacji:
2002-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
81.05.Kf
81.70.Pg
Opis:
This paper reports the results of a short investigation on the effect of Cu additions upon the nanocrystallization behaviour of an Al-Mm-Ni alloy. 2 at.%Cu added to a base alloy of Al$\text{}_{85}$Mm$\text{}_{10}$Ni$\text{}_{5}$ alloy by substitution for Mm (mischmetal). The control of cooling rate did not cause the formation of nanocrystals of fcc-Al phase. The nanocrystalline structure fcc-Al + amorphous phase in quarternary alloy was obtained by isothermal annealing and continuous heating method, but the last technique is more effective. The volume fraction, lattice parameter, and size of Al-phase were calculated.
Źródło:
Acta Physica Polonica A; 2002, 102, 2; 175-179
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Terpolymer Addition on the Thermal and Termomechanical Properties of Poly(Phenylene Sulfide)
Autorzy:
Cetin, B.
Sahin, A.
Yilmaz, T.
Sinmazcelik, T.
Curgul, I.
Powiązania:
https://bibliotekanauki.pl/articles/1033681.pdf
Data publikacji:
2017-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
83.85.Vb
61.41.+e
Opis:
Poly(phenylene sulfide) (PPS) is one of the high-performance engineering polymers and it exhibits superior behavior, such as electrical insulation, dimensional and thermal stability, chemical resistance for various industrial applications. In addition to this, PPS has a high degree of crystallinity and it maintains these properties at high temperatures. These advantageous properties of PPS can be dependent on its chemical structure, composed of phenyl groups linked by a sulfur atom, which gives rigidity to the polymer chains. Owing to these properties, PPS is widely used in electrical and electronic components, automobile industry and mechanical applications. On the other hand, brittleness of PPS restricts its further applications. For this reason, ethylene-acrylic ester-glycidyl methacrylate terpolymer (Lotader®-AX8900) was used to overcome the brittleness of PPS. The effects of terpolymer addition on the thermal and thermomechanical properties of blends were investigated in this study. PPS/Lotader (0, 2, 5, 10 wt.% Lotader®) blends of various compositions were prepared. The blends were prepared by using laboratory scale micro compounder and injection molding machine. Thermomechanical and thermal properties of blends were investigated by means of dynamic mechanic analysis and differential scanning calorimeter test methods. As a result of this study, it was found that increasing loading level of Lotader® significantly decreased the crystallinity and increased glass transition temperature of PPS. On the other hand, Lotader® addition did not affect the melting temperature of PPS considerably. Results of dynamic mechanic analysis test revealed that while damping factor peak and loss modulus values of blends increased with the addition of Lotader®, storage modulus of blends decreased with the increasing loading level of Lotader®. When all test results are considered, it can be concluded that Lotader addition changes the brittle nature of PPS to ductile nature. In addition to this, 2 wt.% Lotader addition to PPS enables the optimum ductility for PPS without deteriorating its other properties.
Źródło:
Acta Physica Polonica A; 2017, 131, 3; 598-600
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High resolution TEM investigations and TDA analysis of zinc alloy with strontium addition
Autorzy:
Labisz, K.
Krupiński, M.
Pawlyta, M.
Matus, K.
Kremzer, M.
Dopierała, K.
Powiązania:
https://bibliotekanauki.pl/articles/1153727.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Og
81.70.Pg
61.66.Dk
Opis:
In this paper there are presented results of high resolution transmission electron microscope investigation concerning the structure of the Zn-Al-Si cast zinc alloy with Sr addition for crystal structure refinement after thermo-derivative analysis performed using the universal metallurgical simulator and analyzer platform. The thermo-derivative analysis allows to determine the specific points of the solidifying alloy, which is helpful for phase determination and proper heat treatment condition determination, allowing to reduce the energy costs and obtaining higher mechanical and functional properties. Using transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurring in the alloy in the state after chemical composition modification as well as after appliance of very precisely controlled cooling rate. The morphology and size of the microstructure of micro-sized eutectic was possible to determine as well the lattice parameters of the Zn α -phase. Particularly the overview will be also directed on the high resolution transmission electron microscope to achieve good insight into the structural changes on the atomic scale.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 823-826
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Thermal Properties of PUF/colored Organoclay Nanocomposites
Autorzy:
Gürses, A.
Doğar, Ç.
Köktepe, S.
Mindivan, F.
Güneş, K.
Aktürk, S.
Powiązania:
https://bibliotekanauki.pl/articles/1193114.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.35.Np
81.70.Pg
62.23.Pq
Opis:
Recently PF resins can be also prepared by the addition of urea because urea accelerates cure process of PF resin, reduces the cost and improves its strength performance. Clays have long been used as inorganic fillers in polymer systems because of low cost, availability and improved thermal properties of resulting polymer composites. Clay nanocomposites of different types yield a marked increase in a number of properties of thermoplastic and other resins and composites. This study investigates the variation of thermal properties of PUF/colored organoclay nanocomposites with increased colored clay ratio. For this the DSC, XRD, FT-IR and HRTEM analyses were made. The XRD patterns and HRTEM images showed that clay platelets were exfoliated at the lower contents of organoclay, whereas at the higher content of organo clay tactoids were observed. The XRD analysis results implied that the amorphous behaviour increased with increased content of colored organoclay. The DSC thermograms indicated that glassy transition temperature (T_{g}) was increased, appearing prominent crystallization peaks at the lower ratios of organoclay. The T_{g} value was partially decreased and the peak intensities gradually decreased with increased content of clay. The thermogram for composite with clay content of 20% was similar to the thermogram of virgin resin. This can be attributed to the shifting of the textural structure for this composite from prominent crystalline structure to amorphous one.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 979-983
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Feederless Casting Limits by Thermal Analysis in Cast Iron
Autorzy:
Erturk, S.
Kumruoglu, L.
Ozel, A.
Powiązania:
https://bibliotekanauki.pl/articles/1030308.pdf
Data publikacji:
2017-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.30.-t
81.30.Fb
81.70.Pg
Opis:
In this study the determinations of melt quality was carried out by thermal analysis of ductile iron. The aim of the study was to determine the limits of feederless casting after the determination of inoculation quality in cast iron. Production method of pouring into a sand mold in the entirety and without using feeder systems has been investigated. Forms of the solidification and volume change have been investigated with simulation program as functions of inoculation quality, type of resin in the mold and mold rigidity. Results of the analysis have been compared with the results of experimental iron casting.
Źródło:
Acta Physica Polonica A; 2017, 131, 3; 370-373
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Decomposition Kinetics of Algerian Tamazarte Kaolin by Differential Thermal Analysis (DTA)
Autorzy:
Sahnoune, F.
Heraiz, M.
Belhouchet, H.
Saheb, N.
Redaoui, D.
Powiązania:
https://bibliotekanauki.pl/articles/1033455.pdf
Data publikacji:
2017-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.30.Lp
81.05.Je
81.05.Mh
81.70.Pg
Opis:
In the present study, the kinetics of meta-kaolinite (Al₂O₃·2SiO₂) formation from Algerian Tamazarte kaolin was investigated by using differential thermal analysis. The differential thermal analysis and the thermogravimetric experiments were carried out on samples between room temperature and 1400°C, at heating rates from 10 to 40°C min¯¹. X-ray diffraction was used to identify the phases present in the samples. The activation energies measured by differential thermal analysis from isothermal and non-isothermal treatments using Johnson-Mehl-Avrami methods with Ligero approximation and using Kissinger-Akahira-Sunose methods were around 145 and 159 kJ/mol, respectively. The Avrami parameter n which indicates the growth morphology parameters were found to be almost equal to 1.60, using non-isothermal treatments, and equal to 1.47 using isothermal treatments. The numerical factor which depends on the dimensionality of crystal growth was 1.60 obtained using Matusita et al. equation. The frequency factor calculated using the isothermal treatment is equal to 1.173× 10⁷ s¯¹. Analysis of the results have shown that bulk nucleation was dominant during kaolinite transformation, followed by three-dimensional growth of meta-kaolinite with polyhedron-like morphology, controlled by diffusion from a constant number of nuclei.
Źródło:
Acta Physica Polonica A; 2017, 131, 3; 382-385
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Preparation and First-Stage Sintering Kinetics of ThO₂-UO₂ Pellets Made by Sol-Gel Microspheres Technique
Autorzy:
Sökücü, A.
Bedir, M.
Aybers, M.
Powiązania:
https://bibliotekanauki.pl/articles/1401228.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.20.Pm
81.20.Fw
81.20.Ev
81.70.Pg
Opis:
The sol-gel method, which is among the methods used for the production of ThO₂-UO₂ mixed oxide fuel pellets, allows a high degree of micro-homogeneity of uranium and thorium in the solution stage. The present study seeks to develop an alternative method in order to produce mixed thorium-uranium dioxide fuel pellets, prepared by internal gelation technique of sol-gel process. The study also aims to investigate shrinkage behavior and first-stage sintering kinetics of pellets compacted in the Ar-5%H₂ atmosphere using a dilatometer. The chemical and physical properties such as density, homogeneity, O/M ratio, metallic impurities, unit cell parameters, phase contents and surface area of powders, that have different compositions of thoria-urania, were studied. The influences of sintering parameters on the characteristics of microspheres and on the properties of sintered pellets are discussed.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 987-991
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Kinetics of Ethylene Decomposition on Iron Catalyst
Autorzy:
Pełech, I.
Narkiewicz, U.
Powiązania:
https://bibliotekanauki.pl/articles/1807641.pdf
Data publikacji:
2009-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
61.05.cp
81.07.Bc
81.16.Hc
Opis:
The effect of ethylene partial pressure and temperature on the hydrocarbon decomposition rate was studied. As a catalyst, a triply promoted iron catalyst (with addition of small amounts of potassium, calcium and alumina oxides) was used. The mean crystallites size was ca. 17 nm. The processes were performed using pure ethylene or ethylene-nitrogen mixture under atmospheric pressure at the temperature range from 400 to 460°C. The growth of carbon mass as a function of reaction time was measured using a thermobalance. The phase composition of the samples after ethylene decomposition was determined using X-ray diffraction technique. The reaction rate was independent of ethylene partial pressure in the range from 0.25 to 1 bar. The maximal carbon yield for given experimental conditions was estimated.
Źródło:
Acta Physica Polonica A; 2009, 116, S; S-146-S-149
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystallisation of Amorphous $Y_{50}Cu_{42}Al_8$ Alloy
Autorzy:
Idzikowski, B.
Śniadecki, Z.
Mielniczuk, B.
Powiązania:
https://bibliotekanauki.pl/articles/1810410.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
61.82.Bg
81.07.Bc
81.70.Pg
Opis:
Amorphous $Y_{50}Cu_{42}Al_8$ ribbon was prepared by melt-spinning technique on the Cu wheel. The crystallisation process was analysed by differential scanning calorimetry and X-ray diffraction. Differential scanning calorimetry curves characterising two crystallisation stages of $Y_{50}Cu_{42}Al_8$ alloy were measured in non-isothermal dynamic mode at different heating rates. Activation energies of both steps of crystallisation process were acquired by the Kissinger method and are equal to 570± 56 and 290±29 kJ/mol for the first and second stage, respectively. By annealing the ribbon at a given temperature for various times the nanocrystalline phase grains of the sizes of about 40 nm in diameter were created. The influence of the annealing temperature on the grain size evolution was also examined.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 147-149
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of technological parameters of the casting process on the structure and selected properties of iron-based metallic glasses
Autorzy:
Pilarczyk, W.
Jung, T.
Babilas, R.
Powiązania:
https://bibliotekanauki.pl/articles/1112027.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cp
81.05.Bx
81.05.Kf
81.70.Bt
81.70.Pg
Opis:
The main aim of this paper was to produce amorphous ribbons with specified composition with the use of various process parameters and X-ray qualitative and quantitative phase analysis after casting and heat treating. Station for ultra-fast cooling of the molten alloy with high vacuum pumps designed for the production of metallic glasses in the form: of ribbons with the use of Bühler Melt Spinner SC was used. The X-ray qualitative and quantitative phase analysis, microscopic observation, microhardness and thermal properties tests of the investigated ribbons were conducted. Based on experimental data the discussion on the correlation between casting process parameters, phase and quantitative composition and heat treatment was carried out.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 923-926
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the structure and thermal properties of intermetallics from Fe-Al system
Autorzy:
Śmiglewicz, A.
Rodak, K.
Tomaszewska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1112888.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
65.40.De
65.60.+a
07.20.-n
Opis:
Selected alloys from the Fe-Al system are included into a group of materials on a matrix of intermetallic phases, and characteristic properties result from it and they constitute a resultant between properties of superalloys and ceramic materials. These materials are characterized, inter alia, by capacity for operating at elevated temperatures, as well as good strength related properties and resistance to oxidation and corrosion at an increased temperature. In addition, a low cost of alloy components and low density caused by aluminium content are their advantages. The basic reasons limiting application of alloys from Fe-Al system as construction materials are current: their low plasticity at room temperature, propensity for brittle cracking, low resistance at elevated temperature, and insufficient creep resistance. This unfavorable characteristics may be improved by adding to alloys such elements as molybdenum, zirconium, carbon, and boron, reducing the size of grains, increasing their purity, stabilizing the solid solution, and causing changes in phase transition temperatures. These alloys may be successfully manufactured by classic melting accompanied with refinement remelting, and ingot casting. In spite of additions and microadditions, grain refining of the initial structure of ingots manufactured in that way is rarely achieved, mainly because of low castability and high casting contraction. In this work we presented the results of structure analysis and investigations of the dilatometric study alloys on the base Fe-Al system. The alloys were obtained by classic casting technique. The studies were carried out on samples after casting and annealing. The phase transformation and thermal expansion investigations of the alloys from Fe-Al system with concentration of Fe-58Al were presented. The linear thermal expansion α was calculated by standard method. The α coefficient was noticed as a temperature function.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 1004-1006
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Activation Energies of Crystallization in Amorphous $RMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5}$ (R = La, Y, Dy) Alloys
Autorzy:
Śniadecki, Z.
Rößler, U.
Idzikowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/1810618.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
61.82.Bg
75.50.Kj
81.70.Pg
Opis:
The effective activation energies, characteristic crystallization temperatures and enthalpies of amorphous $RMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5}$ (R = Y, La, Dy) alloys produced using melt-spinning technique were investigated by differential scanning calorimetry. X-ray diffraction measurements were performed for as-quenched and annealed samples. The crystalline structure of annealed $YMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5}$ and $DyMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5}$ alloys was determined as orthorhombic $TbFe_6Sn_6$-type with Cmcm (63) space group. The alloy with Y appears as a more useful non-magnetic analogue for $DyMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5}$ than the La-based alloy. The differential scanning calorimetry curves for Dy- and Y-based alloys also exhibit similar thermal behavior. The effective activation energies $E_a$ were determined using the Kissinger approach and high values up to 778±74 kJ/mol for La-based sample were established. The comparison of Y-, La-, and Dy-based alloys suggests improvement of thermal stability with the increase in rare-earth element atomic radius in the glassy $RMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5}$ systems.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 409-412
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism and kinetic parameters of the thermal decomposition of gibbsite Al(OH)₃ by thermogravimetric analysis
Autorzy:
Redaoui, D.
Sahnoune, F.
Heraiz, M.
Raghdi, A.
Powiązania:
https://bibliotekanauki.pl/articles/1057886.pdf
Data publikacji:
2017-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Pg
81.05.Je
81.05.Mh
81.30.Mh
07.85.Nc
Opis:
In this study, the mechanism and the kinetic parameters of the thermal decomposition of gibbsite Al(OH)₃ were studied by differential thermogravimetry technique under non-isothermal conditions, between room temperature and 1200 K at heating rates of 5, 10, 15 and 20°C min¯¹. The obtained differential thermogravimetry curves show clearly three distinct peaks. The first peak is due to the partial dehydroxylation of gibbsite. Among the 32 types of differential equations of non-isothermal kinetics, we have found that the most suitable mechanism is (A_{3/2}: g(x)=[-ln(1-x)]^{2/3}) also called Avrami-Erofeev equation of order 2/3. The values of the activation energy E_{A} and of the pre-exponential factor K are 157 kJ mol¯¹ and 7.58×10¹⁵ s¯¹, respectively. The second peak corresponds to the decomposition of gibbsite to boehmite. Decomposition is controlled by the rate of second-order reaction (F₂: g(x)=(1-x)¯¹-1), under the applied conditions. The activation energy E_{A} and pre-exponential factor K correspond to 243 kJ mol¯¹ and 3.73×10²² s¯¹, respectively. The third peak is due to transformation of boehmite to alumina. However the mechanism for such transformation is better described by the 3/2 rate order reaction (F_{3/2}: g(x)=(1-x)^{-1/2}-1). In addition, the values of E_{A} and K were determined to be around 296 kJ mol¯¹ and 1.82×10¹⁹ s¯¹, respectively. The results of differential thermogravimetry were supplemented by the differential thermal analysis. X-ray powder diffraction analysis was carried out for samples of gibbsite treated at different temperatures between 200 and 1200°C in 200°C steps.
Źródło:
Acta Physica Polonica A; 2017, 131, 3; 562-565
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Glass and Glass-Ceramics Produced from Fly Ash and Boron Waste
Autorzy:
Ercenk, E.
Sen, U.
Bayrak, G.
Yilmaz, S.
Powiązania:
https://bibliotekanauki.pl/articles/1181592.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Fs
64.70.P-
61.05.cp
81.70.Pg
62.20.Qp
Opis:
In the current study, the effect of boron waste addition on some properties of fly ash based glass and glass-ceramics were investigated. The powder compositions including 10, 30, and 50 wt% boron waste was prepared. All the investigated compositions were melted at 1500C by using electrical furnaces. Melting structures were cast into the graphite mold. Thus, fly ash-boron waste based glass materials were produced. To transform the glass-ceramic, crystallization process was performed. Crystallization and glass-transition temperatures were determined by differential thermal analysis. Highly dense and crystalline materials, predominantly composed of diopside and augite together with tincalconite and residual glassy phase, were detected by X-ray diffraction analysis after heat treatment at 800, 900, and 1000C for 1 h. For the glass and glass-ceramic samples, mechanical tests such as hardness and fracture toughness were realized. A boron waste addition has a positive effect on the hardness of the specimens unlike the fracture toughness results. Furthermore, produced glass-ceramic materials were characterized via scanning electron microscopy.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 626-628
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Emission During Firing of the Illite-Based Ceramics with Fly Ash Addition
Autorzy:
Knapek, M.
Húlan, T.
Dobroň, P.
Chmelík, F.
Trník, A.
Štubňa, I.
Powiązania:
https://bibliotekanauki.pl/articles/1402156.pdf
Data publikacji:
2015-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.70.ph
61.43.Fs
65.60.+a
81.70.Pg
43.40.Le
Opis:
In this work, illite-based ceramic body with power plant fly ash addition (60 wt.% of illite, 30 wt.% of fly ash and 10 wt.% of illite fired at 1100°C) was investigated by the thermal analysis techniques (differential thermal analysis, thermodilatometry and thermogravimetry) and the acoustic emission technique. The green body was heated up to 1100°C at three different rates 2.5, 5, 10 K/min. The most intense acoustic emission was recorded at the highest rate 10 K/min. Mutual correlations between thermal analyses and acoustic emission data were also examined. The first acoustic emission response appears at 430°C, corresponding to a small endotherm on the DTA curve, where the thermal decomposition of mineral portlandite takes place. In the temperature range from 600 to 900°C, high acoustic emission activity correlates with dehydroxylation and expansion of the sample. At temperatures higher than 800°C, the source of acoustic emission signals is the thermal decomposition of calcite. The amorphous phase created from illite at 920°C becomes pyroplastic, therefore it is not documented by the acoustic emission technique.
Źródło:
Acta Physica Polonica A; 2015, 128, 4; 783-786
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Analysis of DSC Curves for Characterization of Intrinsic Properties of NiTi Shape Memory Alloys
Autorzy:
Ziółkowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1419019.pdf
Data publikacji:
2012-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Ln
81.30.Kf
81.70.Pg
82.60.Fa
62.20.fg
87.85.J-
Opis:
Differential scanning calorimetry is discussed as a tool for characterization of shape memory alloy materials with the example of $Ni_{51at.%}-Ti$ polycrystalline material. Some inconsistencies connected with the differential scanning calorimetry analysis results present in the contemporary literature are indicated, for example large discrepancies in the registered heats of phase transition or differences in registered heats of forward and reverse phase transition, especially in the case of multi-stage phase transition sequences. An attempt is undertaken to explain some of the discrepancies. The overall conclusion from the present work is that forward and reverse sensible heats of phase transition are equal, and discrepancies reported in the literature are artefacts. It is recommended that as a standard practice of differential scanning calorimetry analysis of shape memory alloy materials not only characteristic temperatures but also sensible heat of phase transition should be reported, which can be done at practically no additional cost.
Źródło:
Acta Physica Polonica A; 2012, 122, 3; 601-605
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on the Crystallization Process of Eu$\text{}^{3+}$:CaSiO$\text{}_{3}$ Gel Using Optical and Thermal Methods
Autorzy:
Andrić, Ž.
Krsmanović, R.
Marinović-Cincović, M.
Dramićanin, T.
Šećerov, B.
Dramićanin, M. D.
Powiązania:
https://bibliotekanauki.pl/articles/2047860.pdf
Data publikacji:
2007-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Gt
61.46.Hk
68.37.Hk
78.67.Bf
81.70.Pg
Opis:
Alkoxy sol-gel technique is an important preparation method for production of rare-earth based phosphors. Crystallization of gel provides a way to prepare phosphors on lower working temperatures than those required for the solid state reactions. CaSiO$\text{}_{3}$ gel samples were obtained through hydrolysis-condensation reactions of tetraethylorthosilicate as silica source. In this work we studied the process of crystallization of Eu$\text{}^{3+}$-activated CaSiO$\text{}_{3}$ gel and decomposition of organic precursors by means of thermal analysis and infrared spectroscopy. Results of scanning electron microscopy and energy-dispersion spectrometry are used to check chemical composition and morphology of synthesized material. Emission spectra and emission lifetime measurements are performed to investigate luminescence properties of Eu$\text{}^{3+}$ doped CaSiO$\text{}_{3}$ powder.
Źródło:
Acta Physica Polonica A; 2007, 112, 5; 969-974
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical and Thermal Investigation of Sol-Gel Derived Eu$\text{}^{3+}$:Y$\text{}_{2}$SiO$\text{}_{5}$ Nanoparticles
Autorzy:
Krsmanović, R.
Andrić, Ž.
Marinović-Cincović, M.
Zeković, I.
Dramićanin, M. D.
Powiązania:
https://bibliotekanauki.pl/articles/2047861.pdf
Data publikacji:
2007-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Gt
61.46.Hk
68.37.Hk
78.67.Bf
81.70.Pg
Opis:
Investigation done on Y$\text{}_{2}$SiO$\text{}_{5}$ nanoparticles doped with Eu$\text{}^{3+}$ ions obtained with the alkoxy sol-gel route is presented in this paper. We investigate the optical and thermal properties of obtained material during the conversion of the gel into nanocrystalline form. Fourier transform infrared spectroscopy and fluorescence spectroscopy of Eu$\text{}^{3+}$ ions are used for the optical characterizations, while thermal analysis is done with thermogravimetric-differential thermal analysis technique. Material exhibits characteristic luminescence emission of the trivalent europium ion.
Źródło:
Acta Physica Polonica A; 2007, 112, 5; 975-980
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of CaO Addition on the Sintering Behaviour of Anorthite Formed from Kaolin and CaO
Autorzy:
Ouali, A.
Sahnoune, F.
Belhouchet, H.
Heraiz, M.
Powiązania:
https://bibliotekanauki.pl/articles/1032557.pdf
Data publikacji:
2017-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Je
81.05.Mh
81.20.Ev
81.70.Pg
65.40.De
65.60.+a
Opis:
Thermal reactions and sintering behavior of kaolin DD3 (Djebel Debbagh, Algeria) and CaO mixtures to obtain dense anorthite ceramics were investigated. Mixed powders were uniaxially pressed and fired between 850 and 1150°C. Firing the pressed specimens yielded a dense anorthite ceramics. The sintered density increased with increase of CaO content and reached the maximum value of 2.57 g/cm³ for the composition containing 10 wt% CaO and fired at 1150°C. Their coefficient of linear expansion of the sintered samples at 1100°C decreases with the addition of CaO. X-ray diffraction experiments carried out on the samples containing varied amount of CaO and fired at the temperatures higher than 1000°C for 2 h showed the presence of only anorthite phase.
Źródło:
Acta Physica Polonica A; 2017, 131, 1; 159-161
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 28

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