PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Corrosion Behaviour Correlation of the Secondary Aluminium Casts in Natural Atmosphere and Laboratory Conditions
Kuchariková L., Liptáková T., Tillová E., Bonek M., Medvecká D.
Archives of Metallurgy and Materials
|
2020
|
Vol. 65, iss. 4
1455--1462
EN
The secondary aluminium alloys are very important material in actual industry from economic and ecological point of view. The secondary aluminium used for production of casts, however, contains some elements, i.e. iron, – affecting physical, chemical and mechanical behaviour. The subject of our investigation has been corrosion behaviour in natural atmosphere of the hypoeutectic AlSi7Mg0.3 cast alloys with various content of iron, because the Fe content affects not only mechanical properties but corrosion resistance, as well. Three types of the AlSi7Mg0.3 cast alloys were exposed for 9 months in natural atmosphere and the measure of their degradation by corrosion was found by determination of the weight loss and the light microscopy. In addition, a scanning electron microscopy (SEM) analyses and evaluation of surface changes were used. The corrosion behaviour in natural atmosphere was compared to results of the carried out electrochemical and exposure laboratory experiments in chloride solutions.
2
Content available Static and Dynamic Mechanical Properties of Nodular Cast Irons
Vaško A., Belan J., Tillová E.
Archives of Metallurgy and Materials
|
2019
|
Vol. 64, iss. 1
185--190
EN
Effects of charge composition on microstructure, mechanical and fatigue properties of nodular cast irons have been studied. For experiments, five melts of nodular cast iron were used – three types of unalloyed nodular cast irons (with different ratio of steel and pig iron in a charge and different additives for regulation of the chemical composition) and two types of alloyed nodular cast irons (SiMo- and SiCu- nodular cast iron). The microstructure of the specimens was evaluated according to a norm and by automatic image analysis. The mechanical properties were investigated by the tensile test, impact bending test and Brinell hardness test. The fatigue tests were carried out at sinusoidal cyclic push-pull loading at ambient temperature. The best mechanical properties were reached in the nodular cast iron alloyed by Si and Cu, what is related to its microstructure.
3
Content available Using Deep Etching in the Study of Eutectic Silicon 3D-Morphology in AlSi7MgTi Cast Alloy
Kuchariková L., Tillová E., Bonek M. S., Chalupová M.
Archives of Metallurgy and Materials
|
2018
|
Vol. 63, iss. 4
2017--2022
EN
The effect of combination grain refinement with AlTi5B1 master (55 ppm) and Sr-modification with AlSr5 master (20, 30, 40, 50 and 60 ppm) on the microstructure, tensile and hardness properties of AlSi7MgTi cast alloy were systematically investigated. Eutectic silicon was studied by optical and scanning electron microscopy after standard (0.5% HF) and deep etching (HCl). Morphology of eutectic Si changes from compact plate-like (as-cast state) to fibbers (after modification). Si-fibbers in samples with 50 and 60 ppm Sr coarsen probably as a result of over-modification. The optimum mechanical properties has the experimental material which was grain refined and modified with 40 ppm of Sr (UTS = 220.6 MPa; ductility = 6.1%, and 82.3 HBW 5/250/15).
4
Content available The comparison of the porosity formation in different casted secondary aluminium alloy
Kuchariková L., Tillová E.
Zeszyty Naukowe. Quality. Production. Improvement
|
2017
|
No. 1 (6)
12--19
EN
The porosity formation in secondary aluminium cast alloys are one of the main aspect which can affect the final properties of casts. Whereas these materials are especially used for production the automotive casts such as engine blocks, cylinder head, chassis components and so on, it is need the production of the casts without deleterious defects. The contributions deals with comparison of the porosity formation in secondary AlSi9Cu3 cast alloy when different moulds (the metallic mould and sand mould) for casting were used. The material was gravity casted in the both mould. The differences in microstructure and porosity formation were studied by using light metallography microscopy and image analyser software. The evolution shows that the experimental material casted into the metallic mould had about 98.78% smaller porosity size in comparison to the material casted into the sand mould, therefore it showed better properties.
5
Content available Study of the precipitation hardening process in recycled Al-Si-Cu cast alloys
Kuchariková L., Tillová E., Matvija M., Belan J., Chalupová M.
Archives of Metallurgy and Materials
|
2017
|
Vol. 62, iss. 1
397--403
EN
The formation of extremely small uniformly dispersed particles of a second phase within the original phase matrix during heat treatment changed material properties. Therefore the characterization of precipitation had been investigated using high resolution transmission electron microscopy (TEM) and electron diffraction of thin foils for an AlSi9Cu3 cast alloy. For investigation the hardening effect onto mechanical properties of aluminium cast was used heat treatment, which consisted from solution treatment at 515°C / 4 hours (h), followed by quenching into water with temperature 50°C and artificial aging using different temperatures 170°C and 190°C with different holding time 2, 4, 8, 16, and 32 hours. The observations of microstructure and substructure reveals that precipitation hardening has caused great changes in size, morphology and distributions of structural components, the formation of precipitates of Cu phases, and the change of mechanical properties as well.
6
Content available Study of Bending Fatigue Properties of Al-Si Cast Alloy
Tillová E., Závodská D., Kuchariková L., Chalupová M., Belan J.
Archives of Metallurgy and Materials
|
2017
|
Vol. 62, iss. 3
1591--1596
EN
Fatigue properties of casting Al-alloys are very sensitive to the microstructural features of the alloy (e.g. size and morphology of the eutectic Si, secondary dendrite arm spacing – SDAS, intermetallics, grain size) and casting defects (porosity and oxides). Experimental study of bending fatigue properties of secondary cast alloys have shown that: fatigue tests up to 106-107cycles show mean fatigue limits of approx. 30-49 MPa (AlSi9Cu3 alloy – as cast state), approx. 65-76 MPa (AlSi9Cu3 alloy after solution treatment) and 60-70 MPa (self-hardened AlZn10Si8Mg alloy) in the tested casting condition; whenever large pore is present at or near the specimen’s surface, it will be the dominant cause of fatigue crack initiation; in the absence of large casting defects, the influence of microstructural features (Si morphology; Fe-rich phases) on the fatigue performance becomes more pronounced.
7
Content available Recycling and properties of recycled aluminium alloys used in the transportation industry
Kuchariková L., Tillová E., Bokůvka O.
Transport Problems
|
2016
|
T. 11, z. 2
117--122
EN
Nowadays, a transportation industry creates a lot of metal scrap because production and use of cars are on the increase worldwide. This is based on the fact that increase in the production of cars increases usage of aluminium alloys in transportation applications. Therefore, it is necessary to reduce the production of components from primary aluminium alloy and increase their replacement with secondary-recycled-aluminium alloys because the production of recycled aluminium alloys is less expensive and less energy-intensive than the creation of new aluminium alloy through the electrolysis. In addition, the recycled aluminium alloys have comparable microstructural parameters and properties as the same primary aluminium alloys.
DE
Dank weltweiter Produktionserhöhung und Benutzung der Fahrzeuge produziert die Verkehrsindustrie heute viel Metallabfall. Wie steigert die Fahrzeugerzeugung, so steigert auch die Benutzung von Aluminiumlegierungen. Es ist nötig, die Produktion von Aluminiumprodukten aus Primäraluminium zu reduzieren. Die Produkte müssen also durch die Produkte aus Sekundäraluminium eingesetzt werden. Während die Schmelzflusselektrolyse bei der Gewinnung von Aluminium aus Bauxit 100 Prozent Energie verbraucht, sind es beim Recycling etwa vier bis sechs Prozent. Das Aluminium-Recycling leistet deshalb einen beträchtlichen Beitrag zur Einsparung von Energie, und dient damit gleichzeitig auch dem Umweltschutz. Noch dazu, die Legierungen vom Sekundäraluminium haben vergleichbare Eigenschaften wie dieselben Legierungen von Primäraluminium.
8
Content available remote The Structure Analysis of Secondary (Recycled) AlSi9Cu3 Cast Alloy with and without Heat Treatment
Hurtalová L., Tillová E., Chalupová M.
Engineering Transactions
|
2013
|
Vol. 61, iss. 3
197--218
EN
Al-Si alloys are very universal materials, comprising of from 85% to 90% of the aluminium cast parts produced for the automotive industry (e.g. various motor mounts, engine parts, cylinder heads, pistons, valve retainer, compressor parts, etc.). Production of primary Al- alloys belong to heavy source fouling of life environs. Care of environment of aluminium is connected to the decreasing consumption of resource as energy, materials, water, and soil, and with an increase in recycling and extension life of products in industry. Recycled (secondary) aluminium alloys are made out of Al-scrap and workable Al-garbage by recycling. The automotive casts from aluminium alloys are heat treated for achieving better properties. Al-Si alloys contain more addition elements, that form various intermetallic phases in the structure. They usually contain a certain amount of Fe, Mn, Mg, and Zn that are present either unintentionally, or they are added deliberately to provide special material properties. These elements partly go into the solid solution in the matrix and partly form intermetallic particles during solidification which affect the mechanical properties. Controlling the microstructure of secondary aluminium cast alloy is therefore very important.
9
Content available Identification and Analysis of Intermetallic Phases in Age-Hardened Recycled AlSi9Cu3 Cast Alloy
Hurtalová L., Tillová E., Chalupová M.
Archive of Mechanical Engineering
|
2012
|
Vol. LIX, nr 4
385--396
EN
Purpose: The influence of age-hardening solution treatment at temperature 515 degrees centigrade with holding time 4 hours, water quenching at 40 degrees centigrade and artificial aging by different temperature 130, 150, 170 and 210 degrees centigrade with different holding time 2, 4, 8, 16 and 32 hours on changes in morphology of Fe-rich Al15(FeMn)3Si2 and Cu-rich (Al2Cu, Al-Al2Cu-Si) intermetallic phases in recycled AlSi9Cu3 cast alloy. Material/Methods: Recycled (secondary) AlSi9Cu3 cast alloy is used especially in automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Microstructure was observed using a combination of different analytical techniques (scanning electron microscopy upon standard and deep etching and energy dispersive X-ray analysis – EDX) which have been used for the identification of the various phases. Quantitative study of changes in morphology of phases was carried out using Image Analyzer software NIS-Elements. The mechanical properties (Brinell hardness and tensile strength) were measured in line with STN EN ISO. Results/Conclusion: Age-hardening led to changes in microstructure include the spheroidization of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases and Al-Al2Cu-Si phases were fragmented, dissolved and redistributed within alpha-matrix. These changes led to increase in the hardness and tensile strength in the alloy.
PL
Cel: Badanie wpływu utwardzania przez starzenie przesycanie w temperaturze 515 stopni Celsjusza z czasem przetrzymywania 4 godz., hartowanie wodne w 40 stopniach Celsjusza, starzenie przyspieszone w różnych temperaturach: 130, 150, 170 i 210 stopni Celsjusza, przy czasach przetrzymywania: 2, 4, 8, 16 i 32 godziny na zmiany w morfologii stopów odlewniczych AlSi9Cu3 z recyklingu wzbogaconych żelazem (Al15(FeMn)3Si2) lub miedzią (Al2Cu, Al-Al2Cu-Si). Materiał i metody: Pochodzący z recyklingu (wtórny) stop odlewniczy aluminium AlSi9Cu3 jest powszechnie używany, zwłaszcza w przemyśle motoryzacyjnym (dynamiczne, odkryte odlewy, części silnika, głowice cylindrów, tłoki itp.). Mikrostrukturę odlewów badano stosując kombinację różnych technik analitycznych (elektronowa mikroskopia skaningowa w połączeniu z analizą rentgenowską z dyspersją energii (EDX), standardową i z głebokim wytrawianiem), co pozwoliło identyfikować różne fazy międzymetaliczne. Ocena ilościowa zmian w morfologii tych faz została przeprowadzona przy wykorzystaniu oprogramowania analizatora obrazów (Image Analyzer NIS-Elements). Właściwości mechaniczne (twardość w skali Brinella i wytrzymałość na rozciaganie) były mierzone zgodnie z normą STN EN ISO. Wyniki i wnioski: Utwardzanie przez starzenie prowadzi do zmian w mikrostrukturze, które polegają na sferoidyzacji krzemu eutektycznego, stopniowej dezintegracji, skracaniu i ścienianiu faz międzymetalicznych wzbogaconych żelazem. Fazy Al-Al2Cu-Si podlegały fragmentacji, zostały rozpuszczone i redystrybuowane w osnowie stopu. Zmiany te prowadzą do wzrostu twardości stopu i jego wytrzymałości na rozciąganie.
10
Content available remote Structural analysis of heat treated automotive cast alloy
Tillová E., Chalupová M., Hurtalová L., Bonek M., Dobrzański L. A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2011
|
Vol. 47, nr 1
19--25
EN
Purpose: The present study is conducted to investigate and to provide a better understanding of the heat treatment T4 (solution treatment at 505, 515 and 525°C, holding time 2, 4, 8,16 and 32 hours, then quenching in warm water in the range from 40°C and natural aging at room temperature during 24 hours) on the microstructure (morphology of eutectic Si, morphology of intermetallic Fe- and Cu-rich phases) and on mechanical properties (tensile strength and Brinell hardness) of recycled (secondary) AlSi9Cu3 cast alloy. Design/methodology/approach: Metallographic samples were selected from tensile specimens (after testing) and prepared by standard metallographic procedures (wet ground, polished with diamond pastes, finally polished with commercial fine silica slurry (STRUERS OP-U) and etched by Dix-Keller, HNO3 or H2SO4 (standard etching) or HCl (deep etching in order to reveal the three-dimensional morphology of phases). The microstructure was studied using an optical microscope Neophot 32 and SEM observation with EDX analysis using scanning electron microscope VEGA LMU II linked to the energy dispersive X-ray spectroscopy (EDX analyser Brucker Quantax). Hardness measurement was performed by a Brinell hardness tester with a load of 62.5 kp (1 kp = 9.807 N), 2.5 mm diameter ball and a dwell time of 15 s. Findings: The results indicate that increasing solution treatment temperature results in spheroidization of eutectic Si, gradual disintegration of iron rich intermetallic phases on base Al15(FeMn)3Si2, dissolution but also melting of intermetallic phases on base Al-Al2Cu-Si. Optimal solution treatment (515°C/4 hours) most improves mechanical properties. Further increases of solution time, leads to alloy elongations, while both, the tensile strength continuously drop. Practical implications: The present study is a part of larger research project, which was conducted to investigate and to provide a better understanding microstructure, heat treatment and mechanical properties of recycled (secondary) Al-Si cast alloy. Originality/value: The paper contributes to better understanding effect of the T4 heat treatment on the microstructure (morphology of eutectic silicon and intermetallic phases) and mechanical properties (tensile strength and Brinell hardness) of recycled cast alloy.
11
Content available remote The degradation processes in high loaded casts
Ďuriníková E., Belan J., Tillová E.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1 spec.
207--210
EN
In this work are described structural changes of jet engine DV–2 turbine blades and effect of degradation process. Turbine blades work in aggressively environs and because of that there are rate among high loaded cast stock. As an experimental material we have chose nickel superalloy ŽS6K with surface heat - resisting alitize layer. Evaluation is slant on largeness wearing over work of certain number of hour in operation. Effect working environs and overrun working temperatures is show changes measures as well as changes macrostructure of basic material blades. Evaluate is advance quantitative metallography through the medium metallographic software NIS element. Quantitative analysis evaluate thickness measures, quality control outer look and lack mixture in the seat, which is not splash, is precede by lack of near another applied protective layer. Allowance is knot on last examination in the area ratings protective heat-resisting layers and gives records for others possible ratings and experiments in this area.
12
Content available remote Influence of technological factors on eutectic silicon morphology in Al-Si alloys
Skočovsky P., Tillová E., Belan J.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 2
169-172
EN
From the background about Al-Si alloys modifying from eutectic silicon morphology and mechanical properties relation point of view is at solving of chosen technological problems used structural analysis and Si morphology quantification. There were solved two concrete problems: parameters of solution annealing AlSi9Cu3 alloy and confirming of laser treatment influence on AlSi7Mg0.3 alloy structure. In both cases have material heating caused spheroidization of eutectic silicon. Optimal regime of AlSi9Cu3 alloy (515 oC/4 hrs.) solution annealing was confirmed based on structural analysis, which have achieved fine globular silicon particles segregation and structural changes study at AlSi7Mg0,3 alloy after laser treatment showed improving of mechanical properties, proved also with metallography analysis. Modern methods of structure analysis application enable to spread present knowledge's in area of technological research.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.