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Wyszukujesz frazę "Kvackaj, T." wg kryterium: Autor


Tytuł:
Post SPD Materials Recovery in Thermal Exposition
Autorzy:
Kvačkaj, T.
Kováčová, A.
Kočiško, R.
Powiązania:
https://bibliotekanauki.pl/articles/1402127.pdf
Data publikacji:
2015-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.07.-b
81.20.Hy
81.40.Cd
Opis:
The mechanical and thermo-physical properties of Cu-Cr-Zr alloys in dependence on processing conditions were studied. The processing conditions consisted of solution annealing at temperature of 1020°C for 60 min followed by water quenching. This was followed by one equal channel angular pressing pass carried out at ambient temperature, ageing treatment ($T_{AT}$∈ (20;480⟩°C, $t_{AT}$∈ ⟨30;150⟩ min) and cooling in water. The maximal strengthening effect coming from dislocations & grain size refinement & precipitation strengthening of ΔHV0.1=130 was achieved at $T_{AT}$=480°C and for $t_{AT}$=120 min. From differential scanning calorimetry analysis, two partial exothermal peaks were recognized and classified as major and minor, these peaks are used to determination the stored energy coming from recrystallization and precipitation ($\Delta H_R$ and $\Delta H_P$). The maximal value in stored energy of $H_{1 \times \text{ECAP}} = 2.923 J//g$ was obtained after 1st ECAP pass.
Źródło:
Acta Physica Polonica A; 2015, 128, 4; 689-692
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the high-temperature behaviour of aluminium alloy EN AW 2014
Wysokotemperaturowe zachowanie stopu aluminium EN AW 2014
Autorzy:
Bidulská, J.
Pokorný, I.
Kvačkaj, T.
Grande, M.
Powiązania:
https://bibliotekanauki.pl/articles/352627.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stopy aluminium
naprężenie płynięcia
równanie konstytutywne
aluminium alloy
flow stress
constitutive equation
hot working
Opis:
The high-temperature behaviour of aluminium alloy EN AW 2014 was investigated in a wide range of deformation temperatures and strain rates. The influence of strain rate and temperature on the peak stress was analysed using the conventional constitutive equation (relating strain rate, flow stress, and temperature) and by means of precise definition of the peak stress value, in the non-linear regression model. Moreover, a study on apparent activation energy of EN AW 2014 stabilized by zirconium was carried out using Arrhenius-type plot. The stress-strain curves exhibit rapid increase up to the peak value followed by a gradual softening up to the material fracture, without the steady state usually observed before the fracture. In terms of formability maps, the presented experimental results exhibit a decrease of ductility, respectively with an increase of strain rate and a decrease of temperature, respectively.
Wysokotemperaturowe zachowanie stopu aluminium EN AW 2014 badane było w szerokim zakresie temperatur i predkości odkształcenia. Wpływ prędkości odkształcenia i temperatury na maksymalne naprężenie analizowany był z użyciem konwencjonalnego podstawowego równania (wiazacego predkość odkształcenia, naprezenie płyniecia i temperature) oraz za pomocą precyzyjnej definicji wartości maksymalnego naprężenia w modelu regresji nieliniowej. Ponadto, analiza obserwowanej energii aktywacji stopu EN AW 2014 stabilizowanego cyrkonem przeprowadzono z użyciem wykresu typu Arrheniusa. Krzywe naprężenie-odkształcenie wykazują gwałtowny wzrost do maksymalnego naprężenia, po którym następuje stopniowe mięknięcie aż do zerwania materiału, bez obszaru stałego zwykle obserwowanego przed zerwaniem. Jesli chodzi o mapy plastycznosci, przedstawione wyniki doświadczalne wykazują spadek plastycznosci, odpowiednio ze wzrostem szybkości odkształcenia oraz ze spadkiem temperatury.
Źródło:
Archives of Metallurgy and Materials; 2011, 56, 4; 981-981
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of fatigue and mechanical properties AlMg1SiCu aluminium alloys
Autorzy:
Mihaliková, M
Lišková, A
Vojtko, M.
Kvačkaj, T.
Powiązania:
https://bibliotekanauki.pl/articles/957961.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
aluminum alloys
mechanical properties
fractography
hardness
equal channel angular pressing (ECAP)
fatigue testing
Opis:
The paper is concerned with an analysis of utility and fatigue properties of industrially produced aluminium alloy, specifically EN AW 6061 (AlMg1SiCu), reinforced with the particles of SiC. The following properties were subject to evaluation: microstructure and sub-structure, mechanical characteristics. All of these mechanical properties in pre- and post- equal channel angular pressed (ECAP) state have been studied. The hardness was evaluated by Vickers hardness test at the load of HV10. The significant part the thesis was devoted to the fatigue properties at cyclic load in torsion. The presented results demonstrate well that the combination of fractography and microscopy can give a significant contribution to the knowledge of initiation and propagation crack in the aluminium alloy.
Źródło:
Advances in Science and Technology. Research Journal; 2015, 9, 28; 56-60
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Porosity Evaluation during ECAP in Aluminium PM Alloy
Autorzy:
Bidulská, J.
Kvačkaj, T.
Bidulský, R.
Actis Grande, M.
Powiązania:
https://bibliotekanauki.pl/articles/1418956.pdf
Data publikacji:
2012-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.07.Bc
81.20.Ev
81.40.-z
Opis:
The main aim of this paper is to show porosity evolution during application of various processing conditions including pressing, sintering and equal channel angular pressure. An aluminium based powder (Al-Mg-Si-Cu-Fe) was used as investigated material. After applying different pressing pressures (400 and 600 MPa), specimens were dewaxed in a ventilated furnace at 400C for 60 min. Sintering was carried out in a vacuum furnace at 610C for 30 min. The specimens were processed by single equal channel angular pressure pass. A significant disadvantage of powder metallurgy processing methods is the presence of porosity. Pores act as crack initiators and, due to their presence, the distribution of stress is inhomogeneous across the cross-section and leads to reduction of the effective load bearing area. The equal channel angular pressure process, causing stress distribution in deformed specimens, made the powder particles to squeeze together to such an extent that the initially interconnected pores transform to small isolated pores. The proposed safety diagram includes the combined effect of stress and strain behaviour during equal channel angular pressure. The "safety line" eliminates and quantifies the effect of large pores as a potential fracture initiation sites with respect to the mechanical viewpoint.
Źródło:
Acta Physica Polonica A; 2012, 122, 3; 553-556
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Fracture Surfaces of New Development Insulated Iron Powder Compounds
Autorzy:
Bidulský, R.
Bidulská, J.
Kvačkaj, T.
Actis Grande, M.
Powiązania:
https://bibliotekanauki.pl/articles/1201089.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
81.20.Ev
81.40.Np
Opis:
Goal of the present paper is the analysis of the fracture surfaces of an Insulated Iron Powder Compound (IIPC) with different additions of aluminium alloy (0.25, 0.5 and 0.75 wt.%), in order to improve the mechanical properties, evaluated as the transverse rupture strength (TRS) with sufficient magnetic properties (mainly represented by the iron loss and coercivity force). Investigation of microstructure and porosity development concluded that improvements in bending strength and impact values require the reduction of surface oxides during the heat treatment, in order to get a proper load bearing area between the adjacent particles.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 154-155
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Approach In The Properties Evaluation Of Ultrafine-Grained OFHC Copper
Nowe podejście do oceny właściwości ultra drobnoziarnistej miedzi OFHC
Autorzy:
Kvačkaj, T.
Kováčová, A.
Bidulská, J.
Bidulský, R.
Kočičko, R.
Powiązania:
https://bibliotekanauki.pl/articles/958234.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
OFHC copper
UFG
ECAP
strain rate
fractography
wear resistance
miedź OFHC
szybkość odkształcenia
fraktografia
odporność na zużycie
Opis:
In this study, static, dynamic and tribological properties of ultrafine-grained (UFG) oxygen-free high thermal conductivity (OFHC) copper were investigated in detail. In order to evaluate the mechanical behaviour at different strain rates, OFHC copper was tested using two devices resulting in static and dynamic regimes. Moreover, the copper was subjected to two different processing methods, which made possible to study the influence of structure. The study of strain rate and microstructure was focused on progress in the mechanical properties after tensile tests. It was found that the strain rate is an important parameter affecting mechanical properties of copper. The ultimate tensile strength increased with the strain rate increasing and this effect was more visible at high strain rates (έ~102s−1) . However, the reduction of area had a different progress depending on microstructural features of materials (coarse-grained vs. ultrafine-grained structure) and introduced strain rate conditions during plastic deformation (static vs. dynamic regime). The wear behaviour of copper was investigated through pin-on-disk tests. The wear tracks examination showed that the delamination and the mild oxidational wears are the main wear mechanisms.
W pracy zbadano szczegółowo statyczne, dynamiczne i tribologiczne właściwości ultra drobnoziarnistej (UFG) beztlenowej miedzi o wysokiej przewodności cieplnej (OFHC). W celu oceny właściwości mechanicznych przy różnych szybkościach odkształcenia, miedź OFHC badano za pomocą dwóch urządzeń w warunkach statycznych i dynamicznych. Ponadto miedź poddano dwóm różnym sposobom przetwarzania, co umożliwiło badanie wpływu struktury. Badanie szybkości odkształcenia i mikrostruktury koncentrowało się na zmianie właściwości mechanicznych po próbie rozciągania. Stwierdzono, że szybkość odkształcania jest ważnym parametrem wpływającym na właściwości mechaniczne miedzi. Wytrzymałość na rozciąganie wzrosła ze wzrostem szybkości odkształcenia i ten efekt był bardziej widoczny przy dużej szybkości odkształcania (ε~102s−1) . Jednak zmniejszenie obrazu przebiegało inaczej w zależności od cech mikrostruktury materiałów (struktura gruboziarnista a struktura ultra drobnoziarnista) i zadanych warunków szybkości odkształcenia podczas odkształcenia plastycznego (warunki statyczne a warunki dynamiczne). Zużycie miedzi badano za pomocą testów zarysowania. Badanie ścieżek zużycia wykazało, że delaminacja i umiarkowane utlenienie to główne mechanizmy zużycia.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2A; 605-614
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hot Compression Test of Heat Resistant Steel
Autorzy:
Fedoriková, A.
Kvačkaj, T.
Kočiško, R.
Bidulský, R.
Petroušek, P.
Powiązania:
https://bibliotekanauki.pl/articles/1032933.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.40.Gh
81.40.Np
02.70.Dh
Opis:
This article deals with the analysis of formability of heat resistant steel type 9Cr-1Mo by physical laboratory simulation - hot compression test. The 9Cr-1Mo steel belongs to modern 9%Cr tempered martensitic steel for high-temperature applications in advanced thermal power plants. The shape of the sample was defined based on numerical simulations. The laboratory simulation of forming process called physical simulation - specifically hot compression test was realized in the temperature range from 500 to 950°C and total deformation in the range from 39 to 52%. Cracks formed during hot compression test in the notches are assessed. Subsequently, the relation between the compression temperature, strain, and crack length was defined. The suitable workability corresponds to the temperature range 650-900°C, it agrees with results of numerical simulations. At a temperature of 900°C there is marginal relative deformation without rupture ε =39.9%, which corresponds to the value according to simulations NCL criteria 0.501.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1340-1343
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Material Recovery of OFHC Cu and FeSi Steel after Processing by Plastic Deformations
Autorzy:
Kvackaj, T.
Kocisko, R.
Bidulska, J.
Luptak, M.
Kovacova, A.
Powiązania:
https://bibliotekanauki.pl/articles/1032938.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.82.Bg
07.20.Mc
81.20.Wk
62.20.F-
81.40.Ef
Opis:
The influence of thermoplastic processes through severe plastic deformations carried out at ambient temperature and through rolling carried out at cryogenic temperature on the recovery for two types of materials was investigated. As experimental materials, there were used oxygen free high conductivity copper and FeSi steel presenting materials with middle and high stacking fault energy, respectively. Both materials have been previously investigated, however mainly considering their material properties. In this study, oxygen free high conductivity Cu was processed by 13 passes through equal channel angular rolling which belongs to the severe plastic deformations group of methods. The rolling of FeSi steel at ambient and cryogenic temperatures was performed using a laboratory duo rolling mill, samples were rolled only by one pass. The aim of this study was to insert the strain to the materials with different stacking fault energy (middle and high) under ambient and cryogenic thermal conditions, respectively, and subsequently to observe the influence of stored energy on structural recovery of materials through differential scanning calorimetry method. This study implies that the recovery process characterized by the mobility of structural defects begins earlier for FeSi steel compared to oxygen free high conductivity Cu.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1315-1318
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Severe Plastic Deformation and Heat Treatment on CuCrZr Alloys
Autorzy:
Kováčová, A.
Kvačkaj, T.
Kočiško, R.
Dragošek, L.
Lityńska-Dobrzyńska, L.
Powiązania:
https://bibliotekanauki.pl/articles/1032905.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.40.Cd
61.72.Ff
Opis:
CuCrZr alloy was subjected to equal channel angular pressing method, belonging to the severe plastic deformation group, followed by heat treatment under different ageing conditions to optimize mechanical properties of the alloy. Before equal channel angular pressing, CuCrZr alloy was treated by solution annealing at temperature 1020°C for 1 h. Afterwards, samples were pressed through an equal channel angular pressing die once at room temperature and subjected to artificial ageing under different conditions (200, 400, 450, 480°C for 30, 60, 90, 120, 150 min). Optimization of the CuCrZr alloy was done through the study of mechanical properties and microhardness as a function of ageing temperature and time considering the progress in microstructural/substructural features.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1336-1339
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Fracture Surfaces of Soft Magnetic Materials
Autorzy:
Bidulská, J.
Kvačkaj, T.
Bidulský, R.
Actis Grande, M.
Ferraris, L.
Powiązania:
https://bibliotekanauki.pl/articles/1533971.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
81.20.Ev
81.40.Np
Opis:
The present paper focused on the analysis of the fracture surfaces of a new development insulated iron powder compound with the addition of the aluminium alloy in order to improve the mechanical properties. Results show that in the pressed state, mainly pores act as crack initiators and due to their presence the distribution of stress is inhomogeneous across the cross-section and leads to the reduction of the effective load bearing area. Investigation of fracture surfaces concluded that improvements in bonding during the pressing process and heat treatment can be helpful in the development of soft magnetic materials to give a suitable combination between pressing pressure, annealing temperature and time as well as magnetic properties.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 800-801
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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