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

Znaleziono wyników: 31

Liczba wyników na stronie
first rewind previous Strona / 2 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  ceramic mould
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 2 next fast forward last
1
Content available The Use of the CUDA Architecture to Increase the Computing Effectiveness of the Simulation Module of a Ceramic Mould Quality Forecasting System
Hojny M., Żaba K., Dębiński T., Porada J.
Archives of Foundry Engineering
|
2020
|
Vol. 20, iss. 4
5--12
EN
This paper presents practical capabilities of a system for ceramic mould quality forecasting implemented in an industrial plant (foundry). The main assumption of the developed solution is the possibility of eliminating a faulty mould from a production line just before the casting operation. It allows relative savings to be achieved, and faulty moulds, and thus faulty castings occurrence in the production cycle to be minimized. The numerical computing module (the DEFFEM 3D package), based on the smoothed particle hydrodynamics (SPH) is one of key solutions of the system implemented. Due to very long computing times, the developed numerical module cannot be effectively used to carry out multi-variant simulations of mould filling and solidification of castings. To utilize the benefits from application of the CUDA architecture to improve the computing effectiveness, the most time consuming procedure of looking for neighbours was parallelized (cell-linked list method). The study is complemented by examples of results of performance tests and their analysis.
2
Content available Influence of Zr on AlSi9Cu1Mg Alloy Cast in Ceramic
Matejka M., Kuriš M., Bolibruchova D., Pastirčák R.
Archives of Foundry Engineering
|
2020
|
Vol. 20, iss. 2
13--18
EN
The article focuses on the analysis of the effect of Zr on the properties of the aluminium alloy AlSi9Cu1Mg. The effect of Zr was evaluated depending on the change in mechanical properties and heat resistance during a gradual addition of Zr with an increase of 0.05 wt. % Zr. Half of the cast experimental samples from each variant were heat treated by precipitation hardening T6 (hereinafter HT). The measured values in both states indicate an improvement of the mechanical properties, especially in the experimental variants with a content of Zr ≥ 0.20 wt. %. In the evaluation of Rm, the most significant improvement occurred in the experimental variant with an addition of Zr 0.25 wt. % after HT and E in the experimental variant with addition of Zr 0.20 wt. % after HT. Thus, a difference was found from the results of the authors defining the positive effect of Zr, in particular at 0.15 wt. %. When evaluating the microstructure of the AlSi9Cu1Mg alloy after Zr alloying, Zr phases are already eliminated with the addition of Zr 0.10 wt. %. Especially at higher levels of Zr ≥ 0.20 wt. %, long needle phases with slightly cleaved morphology are visible in the metal matrix. It can be stated that a negative manifestation of Zr alloying is expressed by an increase in gassing of experimental alloys, especially in variants with a content of Zr ≥ 0.15 wt. %. Experimental samples were cast into ceramic moulds. The development of an experimental alloy AlSi9Cu1Mg alloyed with Zr would allow the production of a more sophisticated material applicable to thin-walled Al castings capable of operating at higher temperature loads.
3
Content available The Role of Recycled Ceramic Material Obtained from the Ceramic Layered Moulds Used in the Investment Casting
Soroczyński A., Haratym R., Biernacki R.
Archives of Foundry Engineering
|
2019
|
iss. 1
71--74
EN
The article presents the role of the ceramic layered moulds used in the investment casting method with new (certified) and recycled material from ceramic moulds (CM) after casting process. The materials that were obtained are mainly aluminosilicates and SiO2. The investigation of changes in the quality of ceramic moulds (including the recycled ceramic material) includes the chemical composition of the ceramics as recovered ceramic material, changes in the particle size of the layered covering material, the gas permeability during the pouring of liquid metal, and the creation of the porosity are presented. Than the thermophysical parameters and dimensional accuracy of the casting manufactured in the new ceramic layered shell moulds were analysed. Additionally the global cost savings and improved ecological conditions in the foundry and its surroundings was estimated.
4
Content available remote Analysis of temperature distribution in shell mould during thin-wall superalloy casting and its effect on the resultant microstructure
Rakoczy Ł., Cygan R.
Archives of Civil and Mechanical Engineering
|
2018
|
Vol. 18, no. 4
1441--1450
EN
This work focuses on the influence of temperature distribution in a shell mould during investment casting of thin wall parts on macrostructure, chemical composition of microstructural constituents and γ/γ′ misfit parameter. A reduction of production costs is associated with the optimization of precision casting technology of aircraft engine critical parts, including control of the solidification front in thin-walled castings of nickel superalloys. Appropriate lost-wax casting parameters lead to the creation of coarse grained structure, desired for high-temperature service applications. As a result of non-equilibrium solidification, substantially large chemical inhomogeneities in the dendrite core and interdendritic spaces are formed. Interdendritic spaces are occupied by constituents formed as a consequence of segregation of alloying elements, namely eutectic islands γ/γ′, borides, carbides, and an intermetallic compound of Ni and Zr. Dendrite cores consist of cubic-shaped γ′ precipitates surrounded by Ni-rich γ channels. Low lattice misfit influences cubic morphology of γ′ precipitates, which is favourable for jet engine application because it can guarantee good creep resistance.
5
Content available Influence of the Al2O3 Solid Phase on the Kinetics of Binding Ceramic Moulds
Kolczyk J., Zych J., Jamrozowicz Ł.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 4
91--96
EN
The investigation results of the kinetics of binding ceramic moulds, in dependence on the solid phase content in the liquid ceramic slurries being 67, 68 and 69% - respectively, made on the basis of the aqueous binding agents Ludox AM and SK. The ultrasonic method was used for assessing the kinetics of strengthening of the multilayer ceramic mould. Due to this method, it is possible to determine the ceramic mould strength at individual stages of its production. Currently self-supporting moulds, which must have the relevant strength during pouring with liquid metal, are mainly produced. A few various factors influence this mould strength. One of them is the ceramic slurry viscosity, which influences a thickness of individual layers deposited on the wax model in the investment casting technology. Depositing of layers causes increasing the total mould thickness. Therefore, it is important to determine the drying time of each deposited layer in order to prevent the mould cracking due to insufficient drying of layers and thus the weakening of the multilayer mould structure.
6
Content available Casting of Titanium Alloys in Centrifugal Induction Furnaces
Karwiński A., Leśniewski W., Wieliczko P., Małysza M.
Archives of Metallurgy and Materials
|
2014
|
Vol. 59, iss. 1
403--406
EN
This paper discusses technical problems related with casting of titanium alloys in centrifugal vacuum furnaces. The potentials of an analysis of the centrifugal casting process carried out in the Flow3D software CFD (Computational Fluid Dynamics) were presented. Simulations were carried out on a model set, which enables casting of two connecting rods for an I.C. engine. Changes in the mould filling process were examined for the three selected spinning velocities of the casting arm. The ranges of the metal flow velocity in mould were calculated as well as metal pressure in mould after reaching a predetermined spinning velocity. The results and the adopted mould geometry enabled determination of the magnitude of stress occurring in mould at the time of filling it with liquid titanium alloy. The paper presents a methodology for testing of the ceramic material strength using a four-point loading arrangement. The strength of the ceramic material was determined on samples heated at different temperatures. The obtained results enabled a thesis to be formulated that for pouring of moulds in a centrifugal vacuum furnace, the layered foundry ceramic moulds can be safely used, and the use of moulds that will provide the directional solidification of metal should be possible as well.
PL
W artykule przedstawiono problemy techniczne związane z odlewaniem stopów tytanu w próżniowych piecach odśrodkowych. Zaprezentowano możliwości analizy procesu zalewania wirującej formy przeprowadzonej w programie Flow 3D CFD (Computational Fluid Dynamics). Obliczenia symulacyjne prowadzono dla zestawu modelowego umożliwiającego odlanie dwóch korbowodów silnika spalinowego. Analizowano zmiany sposobu wypełniania formy dla trzech wybranych prędkości wirowania ramienia odlewniczego. Obliczono zakresy prędkości przepływu metalu w formie oraz ciśnienia metalu występującego w formie po osiągnięciu założonej prędkości obrotowej. Uzyskane wyniki oraz przyjęta geometria formy pozwoliły na wyznaczenie wielkości naprężeń występujących w formie w momencie wypełnienia jej ciekłym stopem tytanu. Przedstawiono metodykę badania wytrzymałości materiału ceramicznego wykorzystującego czteropunktowy układ obciążający. Wyznaczono wytrzymałość materiału ceramicznego dla próbek wygizewanych w różnych temperaturach. Otrzymane wyniki pozwalają na przedstawienie tezy, że w podczas zalewania form w próżniowym piecu odśrodkowym będzie można bezpiecznie wykorzystywać warstwowe ceramiczne formy odlewnicze, oraz będzie możliwe zastosowanie form zapewniających założone kierunkowe krzepnięcie metalu.
7
Content available Ceramic Mould Internal Structure Anomalies in the Lost Wax Process
Biernacki R., Grześ J., Haratym R., Tomasik J.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 1 spec.
57--62
EN
The paper analyzes the structure of the ceramic mould, which include discussion about its structure creation. The results of research relate to the strength of the ceramic mould and its thermophysical properties. Structural anisotropy was found and its influence on the mould surface morphology depending on its position with respect to the sprue in the assembly set. The paper also presents evaluation of microgeometry of patterns, ceramic mould and casts produced in a joint production process. Last part includes the results of the fractal dimension measurements of ceramic mould cross-sections. The analysis was based on the mould porosity. For the analyzed structures the percentage of pores and linear fractal dimension was determined, using the line counting dimension method (LCD), which is a modification of box counting dimension method (BCD).
8
Content available Non-ferrous Metals Precision Casting Shape Accuracy in Terms of Ceramic Moulds Anisotropic Material Properties
Biernacki R., Haratym R., Kwapisz J.
Archives of Foundry Engineering
|
2013
|
Vol. 13, iss. 1 spec.
5--8
EN
Shape accuracy analysis of aluminum alloy castings was made in function of ceramic mould properties. Taken it to account was anisotropy of those properties, including influence of ceramic mould properties on the porosity of castings. Ceramic moulds strains, which occur in sintering phase, were evaluated with taking into account the design and production process.
9
Content available New investigation method of the permeability of ceramic moulds applied in the investment casting technology
Zych J., Kolczyk J., Snopkiewicz T.
Archives of Foundry Engineering
|
2013
|
Vol. 13, iss. 2
107--112
EN
The new investigation method of a permeability of ceramic moulds applied in the investment casting technology, is presented in the paper. Some concepts of performing permeability measurements are shown. Investigations in which the influence of the solid phase fraction in the liquid ceramic moulding sand (LCMS) on a permeability of a multi-layer ceramic mould were performed and discussed. The permeability was estimated during two the most important stages of the technological process: in the first – after wax melting and in the second – after mould annealing. Also an influence of the matrix grain sizes (material for sprinkling) on a ceramic mould permeability was estimated.
PL
W pracy przedstawiono nową metodę badań przepuszczalności form ceramicznych stosowanych w technologii wytapianych modeli. Zaprezentowano koncepcje prowadzenia pomiarów przepuszczalności form ceramicznych. Wykonano badania, w których określono wpływ udziału fazy stałej w ciekłej masie ceramicznej (CMC) na przepuszczalność wielowarstwowej formy ceramicznej. Oceniono przepuszczalność w dwóch najważniejszych etapach procesu technologicznego: w pierwszym - po wytopienia wosku oraz w drugim - po wyżarzeniu formy. Oceniono również wpływ wielkości ziarna osnowy, zwanej potocznie „obsypką” (materiałem do obsypywania), na przepuszczalność formy ceramicznej.
10
Content available remote Ceramiczne materiały spiekane wytwarzane z materiałów odpadowych form ceramicznych stosowanych do odlewów precyzyjnych
Drajewicz M., Pytel M.
Materiały Ceramiczne
|
2012
|
T. 64, nr 4
473-477
PL
Niniejsza praca dotyczy badań na temat możliwości wytworzenia materiałów spiekanych w procesie recyklingu form ceramicznych użytych do wykonania precyzyjnych odlewów elementów silników lotniczych. Na podstawie przeprowadzonych badań proszków przed i po procesie mielenia oraz prób ich prasowania i spiekania stwierdzono, że możliwy jest proces recyklingu zużytych form ceramicznych, stosowanych na odlewy precyzyjne elementów silników lotniczych. Do prasowania stosowano proszki ze zmielonych form bez dodatków oraz z dodatkami modyfikatorów. W obu przypadkach uzyskano dobre rezultaty w procesie prasowania i spiekania. Powierzchnie wyprasek i spieczonych próbek były gładkie i nie ulegały rozwarstwieniu, a także nie wykruszały się.
EN
The present work relates to investigations of the possibility to produce sintered materials in the recycling process of ceramic moulds coming from precise casts for air engines elements. On the basis of conducted investigations of powders before and after milling, and tests of their pressing and sintering it has been affirmed that the recycling process of the spent ceramic moulds is possible. It was applied to presses the powders derived from the ground moulds with and with no additions of modifiers were studied. Both types of the powders gave good results when processed by pressing and sintering. Surfaces of compacts and sintered bodies were smooth, and did not undergo foliation, and also they did not crumble.
11
Content available Ocena możliwości wykorzystania w odlewnictwie gipsu syntetycznego uzyskanego podczas procesu mokrego odsiarczania spalin w energetyce
Biernacki R., Haratym R., Krzyńska A.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 1s
5--8
PL
Przedstawiono analizę możliwości wykorzystania w odlewnictwie gipsu odpadowego (syntetycznego) uzyskiwanego w procesie odsiarczania spalin w energetyce. Energetyka jest jednym z największych producentem SO2. W celu ochrony środowiska i obniżenia ilości zanieczyszczeń stosuje się odsiarczanie spalin metodą mokrą. W wyniku tego procesu powstaje gips odpadowy, który może być stosowany w praktyce. Przeprowadzono badania, w wyniku których określono sposoby przygotowania tego gipsu do wykonywania form odlewniczych. W artykule oceniono skład chemiczny, wytrzymałość i przepuszczalność form z uzyskanego gipsu syntetycznego, porównano je z właściwościami gipsu odlewniczego GoldStar XL oraz właściwościami form ceramicznych. Zbadano strukturę gipsów, wykonano badania na derywatografie oraz określono energochłonność procesu wytwarzania gipsu odpadowego w instalacji mokrego odsiarczania. Po analizie zebranych danych można stwierdzić, że gips syntetyczny może być używany jako materiał na formy odlewnicze. Nie obserwuje się znaczącego spadku najważniejszych właściwości, a z drugiej strony istnieje wiele dodatkowych korzyści, w tym niskie zużycie energii, obniżenie kosztów i zmniejszenie wpływu na środowisko.
EN
This article investigates possible use of waste gypsum (synthetic), recovered via flue-gas desulfurization from coal-fired electric power plants, in foundries. Energy sector, which in Eastern Europe is mostly composed from coal-fired electric power plants, is one of the largest producers of sulfur dioxide (SO2). In order to protect the environment and reduce the amount of pollution flue-gas desulfurization (FGD) is used to remove SO2 from exhaust flue gases of fossil-fuel power plants. As a result of this process gypsum waste is produced that can be used in practical applications. Strength and permeability tests have been made and also in-depth analysis of energy consumption of production process to investigate ways of preparing the synthetic gypsum for casting moulds application. This paper also assesses the chemical composition, strength and permeability of moulds made with synthetic gypsum, in comparison with moulds made with traditional GoldStar XL gypsum and with ceramic molds. Moreover examination of structure of synthetic gypsum, the investigations on derivatograph and calculations of energy consumption during production process of synthetic gypsum in wet flue-gas desulfurization were made.
12
Content available Gating systems for sizeable castings from Al alloys cast into ceramic moulds
Stachovec I., Horáček M., Zemčík L., Kolda V., Horenský J.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 2
65-68
EN
In contrast to casting to conventional non-reusable 'sand' moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly) on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all) any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.
13
Content available Evaluation of synthetic gypsum recovered via wet flue-gas desulfurization from electric power plants for use in foundries
Biernacki R., Haratym R., Kwapisz J.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 3
5-8
EN
This article investigates possible use of waste gypsum (synthetic), recovered via flue-gas desulfurization from coal-fired electric power plants, in foundries. Energy sector, which in Eastern Europe is mostly composed from coal-fired electric power plants, is one of the largest producers of sulfur dioxide (SO2). In order to protect the environment and reduce the amount of pollution flue-gas desulfurization (FGD) is used to remove SO2 from exhaust flue gases of fossil-fuel power plants. As a result of this process gypsum waste is produced that can be used in practical applications. Strength and permeability tests have been made and also in-depth analysis of energy consumption of production process to investigate ways of preparing the synthetic gypsum for casting moulds application. This paper also assesses the chemical composition, strength and permeability of moulds made with synthetic gypsum, in comparison with moulds made with traditional GoldStar XL gypsum and with ceramic moulds. Moreover examination of structure of synthetic gypsum, the investigations on derivatograph and calculations of energy consumption during production process of synthetic gypsum in wet flue-gas desulfurization were made. After analysis of gathered data it's possible to conclude that synthetic gypsum can be used as a material for casting mould. There is no significant decrease in key properties, and on the other hand there is many additional benefits including low energy consumption, decreased cost, and decreased environmental impact.
14
Content available Anizotropia właściwości fizycznych form ceramicznych wpływających na ekologiczne wytwarzanie aluminiowych odlewów precyzyjnych
Haratym R., Lewiński J., Biernacki R., Kowaluk T.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 1s
53--56
PL
W referacie przedstawiono analizę parametrów powodujących anizotropię właściwości fizycznych form ceramicznych wpływającą na jakość odlewów z aluminium. Przeprowadzono ocenę oryginalnych badań takich, jak przepływ gazów przez ścianki formy, trzypunktowa ocena wytrzymałości formy na zginanie, stan warstwy wierzchniej formy w aspekcie jej zwilżalności przez ciekły metal oraz sprawdzono porowatość formy ceramicznej w badaniach z użyciem tomografu komputerowego. Przeprowadzono ocenę wpływu właściwości form ceramicznych na jakość odlewów w aspekcie ich wytwarzania.
EN
The paper presents analysis of parameters affecting the anisotropy of ceramic moulds physical properties which affect quality of aluminum castings. An evaluation of original research, such as the permeability of mould surface, three-point bending strength, the state of mould surface layer in terms of wettability by the liquid metal, and ceramic molud porosity tested in studies using a CT (computerized tomography) scanner. Investigation of impact made by ceramic mold properties on casting quality in terms of their production was also made.
15
Content available Dependence of tensile wet strength from regeneration time and grain size of the matrix ceramic moulds
Kamińska J., Kolczyk J., Żymankowska-Kumon S.
Metallurgy and Foundry Engineering
|
2011
|
Vol. 37, no. 1
53-61
EN
Production technology of nwestment casting involves transmitting the elements of shape, dimensions and properties by filling in the appropriate liquid metal ceramic forms reproduced by a model made of wax removed by melting it. The manufacturing process of inwestment casting in the lost wax technology consists of a number of technological operations: preparing of wax models and their assembling in the model units, the preparation of ceramic mixture, successive layers of debris, wax melting in an autoclave, drying the samples at 100 °C, heating the samples at temperatures ranging from 400 to 700 °C. So far, the technology was based on the use of ceramic mixture, which the bond was hydrolysed ethyl silicate. Currently, due to environmental protection and improvement of working conditions, more and more binders with alcohol is replaced with an aqueous solution of colloidal silica. In the study, to create the individual layers a ceramic form, used regenerated ceramic mixture derived from foundry and green ingredients. The regeneration time was respectively 5 and 15 minutes. Used ceramic moulds after mechanical reclamation was given to sieve analysis to determine the grain size (di). Grain sizes 0.2, 0.4 and 0.63 mm were used for the coating of ceramic moulds. The paper presents results of research aimed at the determination of the relationship between tensile wet strength and grain size of ceramic mould: Rm = f[dL). Tests were conducted on cylindrical samples, which deposited the layers of reclaimed ceramic material.
PL
Technologia wytwarzania precyzyjnych odlewów polega na nadawaniu elementom kształtu, wymiarów i odpowiednich własności poprzez wypełnienie ciekłym metalem formy ceramicznej odtworzonej przez model wykonany z wosku, usuwany z niej metodą wytapiania. Proces wytwarzania odlewów precyzyjnych w technologii wytapianych modeli składa się z szeregu operacji technologicznych obejmujących: wykonanie modeli woskowych i ich łączenie w zespoły modelowe, przygotowanie masy ceramicznej, nanoszenie kolejnych warstw, wytopienie wosku w autoklawie, suszenie próbek w temperaturze 100 °C, wygrzewanie próbek w zakresie temperatury od 400 do 700 °C. Dotychczasowa technologia oparta była na stosowaniu mas ceramicznych, w których spoiwem był zhydrolizowany krzemian etylu. Aktualnie, ze względu na ochronę środowiska i poprawę warunków pracy, coraz częściej spoiwo z alkoholem zastępowane jest wodnym roztworem krzemionki koloidalnej. W badaniach do tworzenia warstw formy ceramicznej stosowano osnowy pochodzące ze zużytych form z odlewni precyzyjnej poddanych regeneracji oraz osnowę świeżą. Czas regeneracji wynosił odpowiednio 5 i 15 minut. Masę po regeneracji mechanicznej poddano analizie sitowej w celu określenia wielkości ziarna dL. Ziarna o wielkości 0,2; 0,4 i 0,63 mm użyto do wykonywania warstw form ceramicznych. W artykule przedstawiono wyniki badań ukierunkowanych na wyznaczeniu zależności pomiędzy wytrzymałością na rozciąganie w stanie na wilgotno i wielkością ziarna osnowy formy ceramicznej: Rm =f(dL). Badania zostały przeprowadzone na próbkach w kształcie walca o powierzchni dzielonej, na które nanoszono warstwy z wykorzystaniem osnowy pochodzącej z regeneracji, jak również ze świeżej osnowy.
16
Content available remote The technology of precision casting of titanium alloys by centrifugal process
Karwiński A., Leśniewski W., Pysz S., Wieliczko P.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 3
73-80
EN
The article describes the development of a procedure for the preparation of foundry ceramic moulds and making first test castings. The presented studies included: - development of technological parameters of the ceramic mould preparation process using water-based zirconium binders and zirconia ceramic materials, where moulds are next used for the centrifugal casting of titanium alloys melted in vacuum furnaces, - designing of pouring process using simulation software, - making test castings, - testing and control of the casting properties. The technological process described in this paper enables making castings in titanium alloys weighing up to about 500 g and used in the majority of technical applications.
17
Content available Impact of analysis method on evaluation of ceramic mould surface microgeometry in the lost wax process
Matysiak H., Haratym R., Kwapisz J., Kłębczyk M.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 3 spec.
131--134
EN
In this article two methods of ceramic mould surface microgeometry analysis were presented. First was a contact method, in which Profilometer S3P produced by Perthen Mahr was used. In second optical method optical profiler Veeco NT 9300 was used for surface microgeometry analysis. Evaluation of the results gathered with those methods was made. It was found that optical analysis method of surface microgeometry give better research possibilities (it’s more optimal).
18
Content available Effect of grain size of the reclaimed matrix ceramic moulds used in the lost wax technology on the strength at high temperature
Kamińska J., Kolczyk J., Żymankowska-Kumon S.
Metallurgy and Foundry Engineering
|
2010
|
Vol. 36, no. 1
31-35
EN
Production technology of investment casting involves transmitting the elements of shape, dimensions and properties by filling in the appropriate liquid metal ceramic forms reproduccd by a model made of wax removed by melting it. The manufacturing process of investment casting in the lost wax technology consists of a number of technological operations: preparing of wax models and their assembling in the model units, the preparation of ceramic mixture, successive layers of debris, wax melting in an autoclave, drying the samples at 100 °C, heating the samples at temperatures ranging from 400 to 700 °C. So far, the technology was based on the use of ceramic mixture, which the bond was hydrolysed ethyl silicate. Currently, due to environmental protection and improvement of working conditions, more and more binders with alcohol is replaced with an aqueous solution of colloidal silica. In the study, as the basic of individual layers a ceramic form, used regenerated ceramic mixture derived from foundry and green ingredients. Used ceramic moulds after mechanical reclamation was given to sieve analysis to determine the grain size (dL). Grain sizes 0.2, 0.4 and 0.63 mm were used for the coating of ceramic moulds. The paper presents results of research aimed at the determination of the relationship between tensile wet strength and grain size of ceramic mould: Rm =f(dL). Tests were conducted on cylindrical samples, which deposited a layer of reclaimed ceramic material.
PL
Technologia wytwarzania precyzyjnych odlewów polega na nadawaniu elementom kształtu, wymiarów i odpowiednich własności poprzez wypełnienie ciekłym metalem formy ceramicznej odtworzonej przez model wykonany z wosku, usuwany z niej metodą wytapiania. Proces wytwarzania odlewów precyzyjnych w technologii wytapianych modeli składa się z szeregu operacji technologicznych obejmujących: wykonanie modeli woskowych i ich łączenie w zespoły modelowe, przygotowanie masy ceramicznej, nanoszenie kolejnych warstw, wytopienie wosku w autoklawie, suszenie próbek w temperaturze 100 °C, wygrzewanie próbek w zakresie temperatury od 400 do 700 °C. Dotychczasowa technologia oparta była na stosowaniu mas ceramicznych, w których spoiwem był zhydrolizowany krzemian etylu. Aktualnie, ze względu na ochronę środowiska i poprawę warunków pracy, coraz częściej spoiwo z alkoholem zastępowane jest wodnym roztworem krzemionki koloidalnej. W badaniach, jako osnowę poszczególnych warstw formy ceramicznej, stosowano zregenerowaną masę ceramiczną pochodzącą z odlewni precyzyjnej, oraz osnowę świeżą. Masę po regeneracji mechanicznej poddano analizie sitowej w celu określenia wielkości ziarna dL. Ziarna o wielkości 0.2; 0.4 i 0.63 mm użyto do wykonywania powłok form ceramicznych. W artykule przedstawiono wyniki badań ukierunkowanych na wyznaczeniu zależności pomiędzy wytrzymałością na rozciąganie w stanie na wilgotno i wielkością ziarna osnowy formy ceramicznej: Rm = f(dL). Badania zostały przeprowadzone na próbkach w kształcie walca o powierzchni dzielonej, na które nanoszono warstwy z zregenerowanej masy ceramicznej, jak również ze świeżej osnowy.
19
Content available remote Influence of the Ceramic Moulds Insulation on the Quality of Gas Turbine Blades Made From the Inconel 713C - Nickel-Based Superalloy
Pieczaba D., Jach A., Guzik E., Sieniawski J.
Archives of Metallurgy and Materials
|
2010
|
Vol. 55, iss. 1
37-43
EN
The influence of mould insulation on the microstructure of the nickel-based superalloy - Inconel 713 C, used in gas turbinę blades, was investigated. Turbinę blade castings were madę in industrial conditions. Three varieties of moulds insulation were used. Based on macroscope, fluorescence (surface defects) and radiographic investigations (internal defects) the quality of the castings was estimated. For selected castings light microscopy observations of cross sections of blades were carried out, as well. The average size and morphology of grains were estimated. It has been found, that the kind of the mould insulation influences the ąuality of castings and should be adjusted to the type of blade.
PL
W pracy ustalono wpływ ocieplenia formy na mikrostrukturę odlewów łopatek turbiny ze stopu Inconel 713C. Wykonano w warunkach przemysłowych odlewy łopatek o szerokości pióra 22 i 30 mm oraz jego długości 50 mm. Stosowano trzy rodzaje ocieplenia form ceramicznych. Jakość odlewów określono na podstawie badań makroskopowych, fluorescencyjnych (wady powierzchniowe) i rentgenowskich (wady wewnętrzne). Dla wybranego odlewu łopatki wykonano badania mikroskopowe. Określono średnią średnicę ziaren i ich rozmieszczenie na przekroju odlewu łopatki. Stwierdzono wpływ sposobu ocieplenia formy na mikrostrukturę pióra łopatek wykonanych ze stopu Inconel 713C. Wyniki badań stanowią podstawę dla dalszych prac dotyczących wpływu ocieplenia form na jakość odlewów łopatek turbin.
20
Content available remote Gas flow through a multilayer ceramic mould in lost wax foundry process
Matysiak H., Haratym R., Kłębczyk M.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 2
155-158
EN
The paper deals with the issues of permeability testing of ceramic moulds used in lost wax foundry process. The main issue in the testing is to provide proper specimens of ceramic moulds (CM). The moulds have to be repeatable and must be free of internal defects of microcrack type that are formed mainly during the removal of patterns from CM in the course of heat treatment. Moreover, the process of forming ceramic moulds must be similar to the general industrial process of CM moulds making regarding their anisotropic structure. The permeability parameter reflecting gas flow through multilayer ceramic moulds was also examined with attention to the investment casting shape accuracy.
first rewind previous Strona / 2 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.