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1
Content available Prototype Stand for Determining Quantities of Gasification Products of Polystyrene Model
Jureczko Michał, Bartocha D.
Archives of Foundry Engineering
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2021
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Vol. 21, iss. 4
15--20
EN
Disposable foundry models constitute an increasingly important role in a unitary large-size foundry. These models have many benefits, but technologies using such materials require an understanding of degradation kinetics at the time of filling. The studies presented in the article determine the size of the polystyrene combustion products used for disposable foundry models. The results were obtained by carrying out the combustion process of the polystyrene model in a special combustion chamber, in different configurations. The pressures generated during thermal degradation vary depending on process parameters such as model density or the use of an additional adhesive binder. The results of laboratory tests may suggest what values of pressure are generated when filling in full-mold and lost foam technologies. The studies provide a prelude to further analysis of materials used for disposable foundry models and quantitative evaluation of their thermal degradation products for computer simulation.
2
Content available Design of Proven Technology of Metal Foam and Porous Metal Casting Production
Radkovský F., Merta V., Obzina T.
Archives of Foundry Engineering
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2021
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Vol. 21, iss. 1
125--131
EN
The article describes the design of a proven technology for the production of metal foam and porous metal by the foundry. Porous metal formed by infiltrating liquid metal into a mould cavity appears to be the fastest and most economical method. However, even here we cannot do without the right production parameters. Based on the research, the production process was optimised and subsequently a functional sample of metal foam with an irregular internal structure - a filter - was produced. The copper alloy filter was cast into a gypsum mould using an evaporable model. Furthermore, a functional sample of porous metal with a regular internal structure was produced - a heat exchanger. The aluminium alloy heat exchanger was cast into a green sand mould using preforms. Also, a porous metal casting with a regular internal structure was formed for use as an element in deformation zones. This aluminium alloy casting was made by the Lost Foam method. The aim is therefore to ensure the production of healthy castings, which would find use in the field of filtration of liquid metal or flue gases, in vehicles in the field of shock energy absorption and also in energy as a heat exchanger.
3
Content available The Aging Time Effects of the Pre-expanded Polystyrene on the Patterns Mechanical Properties
Buczkowska K., Pacyniak T.
Archives of Foundry Engineering
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2015
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Vol. 15, iss. 1
131--137
EN
The aging granulate is to activate the blowing agent during the manufacturing process to granulate models can re-expand and shape the model of well-sintered granules, smooth surface and a suitable mechanical strength. The article presents the results of studies which aim was to determine the optimum time for aging pre-foamed granules for pre-selected raw materials. The testing samples were shaped in an autoclave, with constant parameters sintering time and temperature. Samples were made at 30 minute intervals. Models have been subjected to flexural strength and hardness.
4
Content available Evaluation of Microwave Heating of Protective Coatings Used in the Lost Foam Technology
Opyd B., Granat K.
Archives of Foundry Engineering
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2015
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Vol. 15, iss. 2
65--70
EN
Presented are results of a preliminary research on determining a possibility to use microwave radiation for drying casting protective coatings applied on patterns used in the lost foam technology. Taken were measurements of permittivity εr and loss factor tgδ at 2.45 GHz, as well as attempts were made of microwave drying of a protective coating based on aluminium silicates, applied on shapes of foamed polystyrene and rigid polymeric foam. Time and results of microwave drying were compared with the results obtained by drying at 50 °C by the traditional method commonly used for removing water from protective coatings. Analysis of the obtained drying kinetics curves demonstrated that selection of proper operation parameters of microwave equipment permits the drying time to be significantly shortened. Depending on kind of the pattern material, drying process of a protective coating runs in a different way, resulting in obtaining different quality of the dried coating.
5
Content available The Research of Properties of Experimental Ceramic Layers
Karwiński A., Żółkiewicz Z.
Archives of Metallurgy and Materials
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2014
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Vol. 59, iss. 2
703--705
EN
In the evaporative pattern casting process, the surface of a polystyrene pattern (Styrofoam) is coated with a ceramic layer. This ceramic layer, which coats the evaporative pattern, should have specific physiochemical properties including: resistance to thermal, chemical, and erosive activity of molten metal and proper permeability for gases which are produced by the evaporative polystyrene pattern. The article presents the research results of properties of experimentally selected ceramic layers applied on a polystyrene pattern in the evaporative pattern casting process.
PL
W procesie wytwarzania odlewów wg metody modeli zgazowywanych na modele polistyrenowe (styropianowe), nakładana jest warstwa pokrycia ceramicznego. Pokrycie ceramiczne, które jest nanoszone na model zgazowywany powinno charakteryzować się określonymi| właściwościami fizykochemicznymi w tym: odpornością na termiczne, chemiczne i erozyjne działanie ciekłego metalu oraz odpowiednią przepuszczalnością gazów wytworzonych z zgazowywanego modelu polistyrenowego. W artykule przedstawiono wyniki badań własności, wytypowanych doświadczalnych powłok ceramicznych, nanoszonych na model polistyrenowy w procesie modeli zgazowywanych.
6
Content available Feeding and Cooling and Time of Thermal Treatment of a Massive Bush Made of the Complex Aluminum Bronze Cast by the Lost Foam
Just P., Pisarek B. P.
Archives of Foundry Engineering
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2014
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Vol. 14, iss. 4
39--44
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.
7
Content available Test bench for analyzing the lost foam process
Kaczorowski R., Just P., Pacyniak T.
Archives of Foundry Engineering
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2013
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Vol. 13, iss. 1
57--62
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.
8
Content available Badanie właściwości filtracyjnych doświadczalnych warstw ceramicznych
Żółkiewicz Z., Jankowski W.
Prace Instytutu Odlewnictwa
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2012
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T. 52, z. 2
51-62
PL
Jednym z podstawowych parametrów decydującym o prawidłowym przebiegu procesu zgazowywania modelu - z równoczesnym zapełnianiem przez ciekły metal formy, są właściwości powłoki ceramicznej nanoszonej na model polistyrenowy. Do tych czynników zalicza się przepuszczalność i wytrzymałość mechaniczną oraz termiczną powłoki. W artykule przedstawiono opracowany przyrząd oraz wyniki badań właściwości filtracyjnych wytypowanych doświadczalnych powłok ceramicznych nanoszonych na model polistyrenowy w procesie modeli zgazowywanych.
EN
One of the main parameters determining proper course of the pattern evaporation process, which takes place in parallel with pouring of the foundry mould with metal, are properties of the ceramic coating applied on a polystyrene pattern. These properties include the permeability and mechanical as well as thermal resistance of the coating. The paper presents the developed measuring apparatus and the results of experimental studies of selected properties of the ceramic coatings applied on a polystyrene pattern used in the lost foam process.
9
Content available remote Wpływ procesu azotonasiarczania na zmianę wymiarów czopa wału korbowego odlanego metodą lost foam ze sferoidyzacją „inmold”
Binienda M., Just P., Komorowski J., Pokrzywa M., Wołowiec E.
Czasopismo Techniczne. Mechanika
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2012
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R. 109, z. 9-M
33--39
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.
10
Content available The influence of the basic styrofoam patterns final shaping parameters on the resistance properties
Pacyniak T., Buczkowska K.
Archives of Foundry Engineering
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2012
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Vol. 12, iss. 4
121-126
EN
This work presents the analysis of the final shaping process of the patterns aimed at determining the influence of the pressure and the time of sintering on the resistance to bending. The analysis of the research results proved that when the pressure of the sintering rises and reaches Ps=2.1 bar the resistance to bending increases, above this level of the pressure the resistance value starts decreasing. The time of styrofoam sintering at which the highest bending resistance values were obtained is ts=90 s. When the sintering pressure is less than 2 bar prolongation of the time of sintering over 90 s causes a slight increase in the resistance, however, at higher pressures prolongation of the time of sintering causes submelting of the styrofoam pattern.
11
Content available The influence of ingate size on the lost foam casting process
Pacyniak T., Kaczorowski R.
Archives of Foundry Engineering
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2012
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Vol. 12, iss. 2
171-174
EN
The article presents analysis of the influence of ingate size on the Lost Foam casting process. In particular, analysis of simulation tests has been carried out to determine the ingate size influence on the rate of filling of the mould cavity, pressure in the gas gap and size of the gas gap. A specially prepared mathematical model of the process and an original calculation algorithm were used in simulation tests of full-mould casting. The tests have indicated that the increase of the ingate size results in the increase of filling rate and increase of pressure of gases in the gas gap. However, significant influence on mould cavity filling occurs only when the ingate size is less than [...]1 cm2.
12
Content available The analysis of the influence of the polystyrene patterns shaping parameters on the resistance properties
Pacyniak T., Buczkowska K., Bogus W.
Archives of Foundry Engineering
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2012
|
Vol. 12, iss. 2
227-234
EN
This work presents the technology of making foam plastics patterns used in casting as well as the final shaping stand. The analysis of the sintering process was carried out aiming at determining the influence of the pressure and the time of sintering on the flexural strength properties. The analysis of the research results confirmed that when the sintering pressure grows to the value of Pa =1,7 bar the flexural strength also increases, when the pressure value is higher than that, the degradation of the material takes place and the strength properties decrease.
13
Content available Influence of time and pressure of forming a pattern on mechanical properties
Pacyniak T., Buczkowska K., Kaczorowski R.
Archives of Foundry Engineering
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2011
|
Vol. 11, iss. 3 spec.
151--156
EN
In this paper, the technology of forming patterns on a research station equipped with an autoclave A-600 of Polish company GROM is presented. This study was conducted to determine the influence of pressure and time of forming a pattern on the bending strength. Analysis of the results confirmed that bending strength increases with increasing the pressure. The time of forming a pattern has a similar effect.
14
Content available remote Effect of pouring temperature on the Lost Foam Process
Pacyniak T., Kaczorowski R.
Archives of Foundry Engineering
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2011
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Vol. 11, iss. 3
149-154
EN
In this study, the analysis of the influence of the pouring temperature on manufacture process of castings by the Lost Foam method was introduced. In particular, numerical simulation results of effect of silumin and grey cast iron pouring temperature on pouring rate and gas gap pressure were analyzed. For simulating investigations of the Lost Foam process introduced mathematical model of the process was used. For calculations, the author's own algorithm was applied. The investigations have proved that with increasing pouring temperature the pouring rate increases, while pressure in the gas gap are decreasing. The author's own investigations showed a more significant effect of the silumin pouring temperature than grey cast iron pouring temperature on the lost foam process.
15
Content available remote Investigations of polystyrene pre-expansion process by use of the test stand equipped with batch pre-expander
Pacyniak T., Kaczorowski R.
Archives of Metallurgy and Materials
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2010
|
Vol. 55, iss. 3
883-888
EN
Technology of polystyrene pre-expansion process by use of test stand equipped with batch pre-expander was displayed. Additionally the test stand is fit out with fluidized bed dryer and silo for aging pre-expanded polystyrene. Studies of pre-expansion process, to determine the effect of the expansion pressure and expansion time on foamed polystyrene granule bulk density , were carried out. Also carried out researches determining influence of drying process and aging time on foamed polystyrene density. Analysis of test results confirmed that with increasing of expansion pressure up to 1,4 bar the bulk density of polystyrene decreases. Similarly, it was found that with increasing expansion time bulk density decreases.
PL
W pracy przedstawiono technologie wstępnego spieniania polistyrenu na stanowisku badawczym wyposażonym w spieniarkę cykliczną. Stanowisko badawcze wyposażone jest w spieniarkę do pracy cyklicznej, suszarkę fluidyzacyjną oraz silos do sezonowania wstępnie spienionego polistyrenu. Przeprowadzono badania procesu wstępnego spieniania mające na celu określenie wpływu ciśnienia spieniania, czasu spieniania, na gęstość nasypowa granulek styropianu. Przeprowadzono również badania mające określić wpływ procesu suszenia i czasu sezonowania na gęstość spienionego styropianu. Analiza wyników badań potwierdziła, że wraz ze wzrostem ciśnienia wstępnego spieniania do ciśnienia 1,4 bar gęstość nasypowa styropianu maleje. Podobnie stwierdzono, że wraz ze wzrostem czasu spieniania gęstość nasypowa maleje.
16
Content available remote The Lost Foam method – pre-expansion process
Pacyniak T., Kaczorowski R., Grom J., Bejger M., Majchrzak B.
Archives of Foundry Engineering
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2010
|
Vol. 10, iss. 2
89--94
EN
In the study, a pre-expansion station, designed by authors, was presented. It consists of a batch pre-expander with a 90 liters capacity foaming chamber, equipped with fluidized-solid dryer of pre-expanded beads and a pneumatic transport system of granules to the silo. Steam is delivered to the pre-expander from the electric vapor generator type LW 40.1. In the study, work principle of the pre-expansion station and pre-expansion tests carried out on this position were presented.
17
Content available remote Effect of pressure in mould on the mould cavity filling in Lost Foam process
Pacyniak T., Kaczorowski R.
Archives of Foundry Engineering
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2010
|
Vol. 10, iss. 4
157--162
EN
In this study, the analysis of the influence of the pressure in mould on manufacture process of castings by the Lost Foam method was introduced. In particular, numerical simulation results of effect of pressure in mould on pouring rate, gas gap pressure and gas gap size were analyzed. For simulating investigations of the Lost Foam process introduced mathematical model of the process was used. In this model in detail was described and derived equation relating to the changes of the gas pressure in the gas gap. The mathematical description uses the equation of gas state and the equation of Darcy’s rate of filtration. Presented studies indicated, that with decrease of pressure in mould the pouring rate increased and the gas pressure in gas gap and gas gap size decreased. For pressures in mould from the range of 20÷100 kPa, pouring rates achieved values from 30÷3 cm/s respectively.
18
Content available remote Effect of thickness of refractory coating on the Lost Foam Process
Pacyniak T.
Archives of Foundry Engineering
|
2009
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Vol. 9, iss. 3
255-260
EN
The analysis of the influence of the thickness of refractory coating on the production process of casts in the Lost Foam process was introduced in the work. It was conducted in the peculiarity the analysis simulating investigations the influence the coating thickness on the pouring rate, pressure in the gas gap and gas gap size. For simulation tests of the Lost Foam process, a mathematical model presented in this study was used. For calculations, the author's own algorithm was applied. Investigations have proved that with increasing thickness of coating the pouring rate decreases, while pressure in the gas gap and the size of the gap are increasing. The author's own investigations have proved a very significant effect of the coating thickness on the Lost Foam process, and specially on the mould pouring rate.
19
Content available remote The effect of refractory coating permeability on the Lost Foam Process
Pacyniak T.
Archives of Foundry Engineering
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2008
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Vol. 8, iss. 3
199-204
EN
The article analyses the effect of refractory coating permeability on the process of casting manufacture by the Lost Foam technique. The analysis was focussed on simulation tests examining the effect of coating permeability on the mould cavity filling rate, pressure in gas gap, and the size of this gap. In simulation tests of the Lost Foam Process, a mathematical model of the process presented in this study and the author's own computation algorithm were used. The computations have proved that with increasing permeability of the protective coating, the pouring rate increases, too, while pressure of gas in the gas gap and the size of the gap are decreasing. The increasing pouring rate ensures correct making of castings, even if their shape is very intricate and the wall cross-sections are very small. Smaller size of the gas gap and lower gas pressure in the gap reduce the risk of mould damage. The author's own investigations confirmed the importance of the refractory coating permeability and its effect on the casting process, mould pouring rate - in particular.
20
Content available remote Pressure of gas in gas gap during Lost Foam Process
Pacyniak T., Kaczorowski M.
Archives of Foundry Engineering
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2007
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Vol. 7, iss. 4
137-140
EN
In the study, a model and some fundamental relationships describing changes of gas pressure in the gas gap during manufacture of castings by the Lost Foam process were described. The mathematical description uses the equation of gas state and the equation of Darcy's rate of filtration. The equations describing changes of gas pressure in the gas gap and the kinetics of melting of a foamed polystyrene pattern as well as the dynamics of the process of mould filling with molten alloy were used in analysis of the effect of selected technological parameters on changes of gas pressure in the gas gap. The effect of foamed polystyrene pattern density and permeability, and of the protective coating thickness on changes of pressure in the gas gap were discussed.
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