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EN
The paper presents the results of research related to the possibility of inoculation of the AZ91 magnesium alloy casted into ceramic moulds by gadolinium. Effects of gadolinium content (0.1–0.6 wt%) on microstructure of the AZ91 alloy under as-cast state were investigated. The influence of the inoculator on the formation of the microstructure investigated by means of the thermal and derivative analysis by analysing the thermal effects arising during the alloy crystallization resulting from the phases formed. The degree of fragmentation of the microstructure of the tested alloys was assessed by means of the light microscopy studies and an image analysis with statistical analysis was performed. Conducted analyses have aimed at examining on the effect of inoculation of the gadolinium on the differences between the grain diameters and average size of each type of grain by way of measuring their perimeters of all phases, preliminary αMg and eutectics αMg+γ(Mg17Al12) in the prepared examined material.
EN
The paper presents the effect of manganese on the crystallization process, microstructure and selected properties: cast iron hardness as well as ferrite and pearlite microhardness. The compacted graphite was obtained by Inmold technology. The lack of significant effect on the temperature of the eutectic transformation was demonstrated. On the other hand, a significant reduction in the eutectoid transformation temperature with increasing manganese concentration has been shown. The effect of manganese on microstructure of cast iron with compacted graphite considering casting wall thickness was investigated and described. The nomograms describing the microstructure of compacted graphite iron versus manganese concentration were developed. The effect of manganese on the hardness of cast iron and microhardness of ferrite and pearlite were given.
EN
The study discusses the issues connected with the production of thin-walled ceramic slurry in the replicast cs technology. In the ceramic mould production process, a special role is played by the liquid ceramic slurry used to produce the first layer of the mould. The study examines selected technological properties of liquid ceramic slurries used to produce moulds in the replicas cs technology. The ceramic slurries for the tests were prepared based on the binders Ludox Px30 and Sizol 030, enriched with Refracourse flour. The wettability of the pattern's surface by the liquid ceramic slurry and the dependence of the apparent viscosity on the ceramic flour content in the mixture were determined. The wettability of the pattern surface by the liquid ceramic slurry was determined based on the measurement of the wetting angle. The angle was determined by means of an analysis of the computer image obtained with the use of a CDC camera.
PL
W pracy poruszone zostały zagadnienia związane z technologią lost foam. Zbadano wpływ rodzaju oraz grubości pokrycia ceramicznego a także gęstości zespołu modelowego na stopień zagazowania odlewu. Badania przeprowadzono dla dwóch rodzajów pokryć ceramicznych Disopast 4805/3 oraz Disopast 7759, które nakładano na modele ze spienionego polistyrenu w jednej, dwóch i trzech warstwach. Tak przygotowane modele wykorzystano do wytworzenia odlewów ze stopu AlSi11 w technologii lost foam. Otrzymane odlewy zbadano pod kątem stopnia ich zagazowania. Zaprezentowane badania wykazały zależności pomiędzy gęstością modelu, rodzajem i grubością zastosowanych powłok ceramicznych, a stopieniem zagazowania odlewów. Wykazano, że badane właściwości mają istotny wpływ na stopień zagazowania odlewu, jego porowatość oraz liczbę gazową. Poprzez odpowiedni dobór pokrycia, jego grubości, gęstości modelu, możliwe jest zminimalizowanie stopnia zagazowania odlewu.
EN
The study addressed the issues associated with lost foam casting technology. The effect of the type and thickness of the ceramic coating and the density of the pattern set of the degree of gas porosity in casting. The study was conducted for two types of ceramic coatings Disopast 4805/3 and Disopast 7759, which was applied to patterns with expanded polystyrene in one, two and three layers. Thus prepared patterns were used to produce castings alloy AlSi11 lost foam technology. The resulting castings were tested for their level of gas porosity. Presented studies have shown the relationship between the density of the polystyrene pattern, type and thickness of the applied ceramic coatings gas porosity and casting melt. It has been shown that investigated the properties have a significant impact on the degree of gas porosity in cast, its porosity and the gaseous number. Through an appropriate choice of coating, its thickness, density model, it is possible to minimize the degree of gassing casting.
EN
Small additions of Cr, Mo and W to aluminium-iron-nickel bronze are mostly located in phases &kappa i (i=II; III; IV),and next in phase &alpha (in the matrix) and phase γ2. They raise the temperature of the phase transformations in aluminium bronzes as well as the casts’ abrasive and adhesive wear resistance. The paper presents a selection of feeding elements and thermal treatment times which guarantees structure stability, for a cast of a massive bush working at an elevated temperature (650–750°C) made by means of the lost foam technology out of composite aluminium bronze. So far, there have been no analyses of the phenomena characteristic to the examined bronze which accompany the process of its solidification during gasification of the EPS pattern. There are also no guidelines for designing risers and steel internal chill for casts made of this bronze. The work identifies the type and location of the existing defects in the mould’s cast. It also proposes a solution to the manner of its feeding and cooling which compensates the significant volume contraction of bronze and effectively removes the formed gases from the area of mould solidification. Another important aspect of the performed research was establishing the duration time of bronze annealing at the temperature of 750°C which guarantees stabilization of the changes in the bronze microstructure – stabilization of the changes in the bronze HB hardness.
EN
This paper presents a technology of ductile cast iron obtain by lost foam process with use of inmold method. Spheroidization was carried out using master alloy in an amount of 1.5% by mass on casting iron. Research the influence of the gating system configuration and the shape of the reaction chamber, the degree of spheroidization cast iron, which estimated based on the shape of the graphite. Research have shown that the greatest impact on the degree of spheroidization has cast the infusion position relative to the casting inlet and the reaction chamber, and the shape of the reaction chamber.
PL
W pracy przedstawiono technologię otrzymywania odlewów z żeliwa sferoidalnego metodą inmold z wykorzystaniem procesu pełnej formy. Sferoidyzację prowadzono z użyciem zaprawy sferoidyzująco-modyfikującej w ilości 1,5% na masę sferoidyzowanego żeliwa. Przeprowadzono badania wpływu konfiguracji układu wlewowego oraz kształtu komory reakcyjnej na stopień sferoidyzacji żeliwa, który określono na podstawie wskaźnika kształtu grafitu. Badania wykazały, że największy wpływ na stopień sferoidyzacji żeliwa ma położenie wlewu doprowadzającego względem odlewu i komory reakcyjnej, oraz kształt komory reakcyjnej.
7
Content available Test bench for analyzing the lost foam process
EN
The current work presents and describes the test bench for analyzing the lost foam process, especially measuring of the pressure of gases in the gas gap and continuous measuring of the rate of rise of the bath level when pouring the liquid metal into the mould. A series of preliminary research was carried out on the bench which was aimed at determining the influence of the basic parameters of the process, i.e. the density of the styrofoam pattern, thickness of the refractory coating applied on the pattern, kind of the alloy and the temperature of pouring on the mould cavity by the liquid metal and the pressure of gases in the gas gap.
EN
The paper presents the optimization of master alloy amount for the high nodular graphite yield (80-90%) in cast iron obtain in lost foam process. The influence of the gating system configuration and the shape of the reaction chamber, the degree of spheroidisation cast iron was examined. Research has shown that the, optimal of master alloy amount of 1.5% by mass on casting iron. The degree of spheroidisation is also influenced by the gating system configuration. The best spheroidisation effect was obtained for liquid cast iron was fed into the reaction chamber from the bottom and discharged from the top.
PL
W artykule przedstawiono wyniki prac nad przetapianiem miedzi w postaci proszku o wielkości ziarna wynoszącego 50 μm, dzięki wykorzystaniu obustronnego, pośredniego grzania oporowego grzałek wykonanych z materiału wysokotopliwego jakim jest wolfram [3]. Grzałki rozmieszczone są jedna nad drugą w odległości 0,02 m, pomiędzy którymi po środku znajduje się podłoże wykonane z materiału o wyższej temperaturze topnienia niż poddawany przetapianiu materiał. Układ grzałek wolframowych zapewnia równomierne rozgrzewanie powierzchni wyżej topliwego podłoża. W artykule przedstawiono schemat urządzenia do przetapiania sproszkowanej miedzi na podłożu wyżej topliwym oraz zdjęcia otrzymanych struktur przetopionej miedzi z procesów wykonanych z wykorzystaniem różnorodnych parametrów prądowych grzania oporowego podłoża.
EN
This paper presents the results of work on the melting of copper in the form of a powder having a particle size of at 50 μm, by using both sides, the intermediate heat resistance heater made of a material which is of a high tungsten. Heaters are placed one above the other at a distance of 0.02 m between which the middle is a substrate made of a material having a higher melting point than the cast material. Tungsten heater circuit is arranged so that the uniformly heating the melt above the surface of the substrate. The paper resents the scheme of the device for melting copper powder on the floor above, fusible, and images obtained melted silicon structures of the processes carried out using a variety of parameters, current resistance heating of the substrate.
PL
W artykule prezentowane są zagadnienia związane z badaniem wpływu zwilżalności wysokotopliwego podłoża na jakość warstw miedzianych wytwarzanych metodą pośredniego grzania oporowego przy obniżonym ciśnieniu. W pracy przedstawiono wyniki badań przetapiania sproszkowanej miedzi na podłożach metalowych o wyższej temperaturze topnienia niż sam surowiec. Metoda ta może znaleźć zastosowanie przy tworzeniu różnego rodzaju bimetali lub może posłużyć także do kierunkowego oczyszczania przetapianego surowca.
EN
The article presents issues related to examination of the impact of wettability of high fusible substrate on a quality of the copper produced by indirect resistance heating at reduced pressure. This paper presents the results of remelting of powdered copper on metal substrates with melting points higher than those for the raw material. This method can be used to create different types of bimetals and may be used also for directional cleaning of remelted material.
PL
W artykule przedstawiono sposób modyfikacji warstwy wierzchniej czopu korbowego metodą azotonasiarczania w celu polepszenia jego odporności korozyjnej, wyeliminowania możliwości zacierania wraz z uzyskaniem wysokiej trwałości elementu dzięki podniesieniu wytrzymałości na ścieranie poprzez zmniejszenie współczynnika tarcia a także zwiększenie twardości powierzchni. Wał korbowy z żeliwa sferoidalnego został odlany w technologii lost foam z sferoidyzacja inmold, obrobiony cieplnie, a następnie poddany obróbce cieplno-chemicznej. Zbadano własności warstwy azotonasiarczonej oraz przyrost wymiarów czopu powstały w wyniku obróbki cieplno-chemicznej.
EN
The paper shows how to modify the surface layer of the crank stud sulfonitriding method in order to improve its corrosion resistance, and eliminate the possibility of scuffing of the element to obtain a high durability by improving the abrasion resistance by decreasing the coefficient of friction and increasing the surface hardness. Ductile iron crankshaft was cast in the lost foam technology of spheroidization inmold, heat treated and then subjected to thermochemical treatment.
EN
The article presents the results of the research on the influence of the shape of reaction chamber on spheroidisation of cast iron produced with use of the inmold method. The amounts of nodular graphite precipitates in castings produced with the use of different reaction chambers have been compared.
EN
In this work was shown a influence analysis foamed polystyrene model on casting defects as well as microstructure ductile cast iron from Lost Foam process with Inmold method.
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