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1
Content available Influence of Microwave Heating on the Molding Mass with Gypsum Binder Structure and Strength
Paduchowicz Patrycja J., Granat K., Biały P.
Archives of Foundry Engineering
|
2021
|
Vol. 21, iss. 1
113--118
EN
The paper presents results of influence microwave drying on strength and technological properties of molding sand with gypsum binder researches, which, immediately after making and after the natural initial setting in air for 1, 2 or 5 hours, was heated with 250 W microwave power for 3, 6, 9 and 12 min time periods. The test was carried out on a mass containing (% -wt.): 88% Grudzeń-Las quartz sand, 12% "Dolina Nidy" plaster gypsum and 6% water. The loss of moisture content during natural drying and then microwave drying was determined, significant from the point of view of using the mass with gypsum binder in the production of products, using an environmentally friendly technology without casting incompatibilities. Additionally, the compressive strength of the mass was measured. The influence of both drying methods on the binder crystallization process and the associated mass strength was demonstrated, especially in terms of the possibility of selecting parameters and / or intensifying a specific drying method for use in the technology of manufacturing molds and foundry cores.
2
Content available remote Charakterystyki korozyjne dentystycznego stopu Remanium G (Ni-Cr-Mo) topionego/odlewanego różnymi technikami
Radomska K., Klimecka-Tatar D., Jagielska-Wiaderek K.
Ochrona przed Korozją
|
2014
|
nr 7
262--268
PL
Stop dentystyczny Remanium G na bazie NiCrMo przetapiano a następnie odlewano na drodze czterech najbardziej rozpowszechnionych technologii stosowanych w laboratoriach dentystycznych, a mianowicie przy zastosowaniu: (A) płomienia palnika tlenowo-acetylenowego jako źródła ciepła w procesach topienia, (B) pieca indukcyjnego, (C) łuku Volty oraz (D) metody Autocast. Głównym celem niniejszej pracy było dokonanie oceny wpływu w/w technik przetapiania i odlewania komercyjnego stopu Remanium G na bazie NiCr-Mo na odporność korozyjną w roztworze Ringera (pH = 6). Oceny odporności korozyjnej dokonano metodami polaryzacji potencjokinetycznej oraz analizy metalograficznej. Przeprowadzone pomiary wykazały, że zastosowane techniki przetapiania/odlewania mają nieznaczny wpływ na odporność korozyjną badanego stopu dentystycznego. Zaobserwowano, że w strukturze stopu Ni-Cr-Mo dendryty zbudowane są głównie z fazy międzymetalicznej γ (fcc) wzbogaconej w nikiel. Zwiększona zawartość molibdenu w składzie stopu powoduje jego silną segregację, i co za tym idzie wzbogacenie obszarów międzydendrytycznych w Mo.
EN
The prosthetic dentistry casting alloy Remanium G based on Ni-Cr-Mo was melted and casted by the four most widespread technologies in dental laboratories: (A) the flame of the oxy-acetylene blowpipe torch as a heat source in a melting process, (B) induction furnace, (C) Volta arc and (D) Autocast method. The main objective of this study was to assess the impact of the most commonly used techniques of melting and casting on corrosion resistance of commercial Remanium G alloy based on NiCrMo in Ringer solution (pH = 6). The evaluation of corrosion resistance of the dental alloy has been carried out by potentiokinetic polarization tests and metallographic analysis. The analysis showed that the type of melting and casting technologies has rather negligible effect on the corrosion resistance of the tested alloy. It was observed that the structure of Ni-Cr-Mo dendrites are composed predominantly of γ intermetallic phase ( fcc ) enriched in nickel. Increased molybdenum content in the alloy composition makes it a strong segregation , and hence enrichment in Mo interdendritic areas.
3
Content available Wybijalność mas ze szkłem wodnym modyfikowanym nanocząstkami MgO
Kmita A., Hutera B.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 4 spec.
55--58
PL
Przedmiotem pracy była modyfikacja szkła wodnego 5% mas. koloidalnym roztworem nanocząstek MgO w propanolu i dokładnej homogenizacji spoiwa. Celem przeprowadzonych badań było określenie wpływu modyfikacji szkła wodnego na wytrzymałość końcową na ściskanie Rctk oraz wybijalność mas z tym spoiwem oznaczonymi w próbie technologicznej zalecanej przez polską normę PN-85/H-11005. Wykazano, że zastosowana modyfikacja korzystnie wpływa na przebieg krzywej Rctk, powodując przesunięcie występowania II maksimum wytrzymałości masy w kierunku wyższych wartości temperatury. Pozytywne oddziaływanie zastosowanej modyfikacji szkła wodnego potwierdzone zostało próbami technologicznymi, w których stwierdzono poprawę wybijalności tych mas o 50% w porównaniu z wybijalnością mas ze szkłem wodnym niemodyfikowanym.
EN
Moulding sands with water glass belong to the group of environment friendly moulding sands. However, due to some disadvantageous technological properties of these sands, such as e.g. difficult knocking out and poor reclamation ability [1, 2], they are not widely applied in the foundry industry. Therefore numerous endeavours aimed at improving the quality of moulding sands with water glass are undertaken. Apart from the modification of the moulding sand matrix composition or controlling the hardening process the quality improvement of these sands can be achieved by means of binder modifications, either chemical or physicochemical. Reactions between water glass components and inoculants are essential in chemical processes. The progress of nanotechnologies occurring during last years, causes that nanomaterials are more and more often applied in several industries including also the foundry industry. Nanoparticles introduced into a binding material can react with it influencing and modifying its selected properties. The subject of the study is the water glass modification by the colloidal solution of MgO nanoparticles in propanol [3]. The aim of the performed investigations is the determination of the binder modification influence on the final compression strength Rctk and knock out property of moulding sands with the modified water glass (marked in the technological test according to the Polish standard: PN-85/H-11005).
4
Content available Nowe żywice furfurylowe bardziej przyjazne dla środowiska
Holtzer M., Kmita A., Roczniak A.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 4 spec.
47--50
PL
Coraz ostrzejsze przepisy w zakresie ochrony środowiska wymuszają na producentach materiałów dla przemysłu odlewniczego opracowywanie nowych produktów, bardziej przyjaznych dla środowiska. Jednym z takich produktów są żywice furfurylowe, które obecnie mają największy udział w grupie mas no-bake. Wprowadzone w ostatnich latach w UE przepisy dotyczące ograniczenia zawartości wolnego alkoholu furfurylowego (< 25%) w żywicach oraz naciski w kierunku redukcji emisji SO2, formaldehydu, fenolu, benzenu i toluenu, jak również związków z grupy WWA, szczególnie na stanowiskach pracy spowodowały pojawienie się na rynku nowej generacji żywic furfurylowch oraz katalizatorów (o zmniejszonej zawartości siarki lub bezsiarkowych). W artykule dokonano analizy wpływu tych nowych produktów stosowanych w technologii mas z żywicami furfurylowymi na środowisko i warunki pracy.
EN
More and more strict regulations, concerning the environment protection, force the producers of materials for foundry industry to develop new products, more friendly for the environment. One of such products are furfuryl resins, which currently have the largest share within the group of no-bake moulding sands. Regulations introduced in the last years in the European Union concerning limitations of a free furfuryl alcohol content (< 25%) in resins as well as pressures to reduce SO2, formaldehyde, phenol, benzene, toluene and compounds from the PAHs group emissions, especially at work stands, caused an appearance of the new generation of furfuryl resins and catalysts (of a decreased sulphur content or even sulphur-free). The analysis of the influence of these new products, applied in the moulding sands with furfuryl resins technology, on the environment and work conditions was performed in the hereby paper.
5
Content available Evaluation of Heat Capacity and Resistance to Cyclic Oxidation of Nickel Superalloys
Przeliorz R., Binczyk F., Gradoń P., Góral M., Mikuszewski T.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 3
67--70
EN
Paper presents the results of evaluation of heat resistance and specific heat capacity of MAR-M-200, MAR-M-247 and Rene 80 nickel superalloys. Heat resistance was evaluated using cyclic method. Every cycle included heating in 1100°C for 23 hours and cooling for 1hour in air. Microstructure of the scale was observed using electron microscope. Specific heat capacity was measured using DSC calorimeter. It was found that under conditions of cyclically changing temperature alloy MAR-M-247 exhibits highest heat resistance. Formed oxide scale is heterophasic mixture of alloying elements, under which an internal oxidation zone was present. MAR-M-200 alloy has higher specific heat capacity compared to MAR-M-247. For tested alloys in the temperature range from 550°C to 800°C precipitation processes (γ′, γ′′) are probably occurring, resulting in a sudden increase in the observed heat capacity.
6
Content available Aspekty technologiczne i systemowe pozyskiwania informacji z otwartych źródeł
Nawarecki E., Kluska-Nawarecka S., Dziaduś-Rudnicka J., Wilk-Kołodziejczyk D.
Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
|
2011
|
T. 15, z. 2
365-373
PL
W pracy rozważany jest problem poszukiwania informacji o charakterze technologicznym z sieci Internet. Przedstawiono wyniki wstępnych eksperymentów dotyczących eksploracji wiedzy o technologiach odlewniczych ze stron WWW. Zaprezentowano również schemat funkcjonalny oraz niektóre procedury obliczeniowe, komputerowego systemu do automatycznego tworzenia problemowo zorientowanych komponentów wiedzy technologicznej.
EN
The paper considers problems related with searching for technological information in Internet. The results of initial experiments in data mining about casting technologies from WWW pages are presented. A functional diagram and some numerical procedures (algorithms) of computer system for automatic creation of problem-oriented components of the technological knowledge are included.
7
Content available remote Towards optimization of stress simulation in real casting-mould systems
Ignaszak Z.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 4
69--76
EN
The simulation codes using from many years by foundry industry such e.g. Magmasoft, NovaFlow&Solid and ProCast, contain also the thermo-mechanical modules permitting the estimation of mechanical stresses/deformations in casting during its cooling. It is also known that these modules are rarely used because of the very limited thermo-mechanical database especially for ceramic materials such as foundry sand mould. These technologies – castings pouring in non-permanent sand moulds, particularly iron alloys are most often applied in foundry. In our study the method of evaluating the algorithms quality applied in thermo-mechanical phenomena models based on parameters sensitivity testing from the proper database of the simulation system was used [1]. The comparative analyses of both experimental and virtual results were realized (by stress estimation). Methodology of experimental research was resemble to that described in provided that the applied gray cast iron casting of stress bars (grid) were casted in sand mould bonded by organic resins. Also the usefulness of author's method called Hot Distortion Plus® consisting in acquisition of temperature/distortion curves of heated sample of sand mould material and correlation with curves of their dilatation and also the inverse solution method are signalized as new proposition to estimate the chosen mechanical moulds parameters.
8
Content available remote The influence of the conditions of gypsum plaster preparation on its technological properties
Pawlak M.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 2
95--98
EN
The results of researches on influence of basic preparation parameters, i.e. time and mixing intensity, start and end time of set, dimensional changes and strength of gypsum plaster, are presented in this paper. Determination of mentioned above parameters has a significant meaning because of their influence on quality of gypsum plaster and its susceptibility to even small disturbances during preparation. Tested plaster was prepared in vacuum mixer St. LOUIS 82. Time of mixing was 60÷360 sec., mixer arm rates 150÷420 rpm. It was demonstrated that mixing time influences strongly the setting time and expansion of gypsum plaster , and this influence growths with growing mixing intensity. The intense, short time mixing is beneficial from the viewpoint of dimensional changes minimizing. Minimizing the setting time is the most beneficial at low mixing intensity but significant dimensional changes appear during setting the plaster.
9
Content available remote Bainitic-martensitic nodular cast iron with carbides
Gumienny G.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 2
63--68
EN
In this paper the possibility obtaining of upper bainite, lower bainite and martensite or their mixture in nodular cast iron with carbides has been presented. Conditions have been given, when in nodular cast iron with carbides for cooling at first in the form, then air-cooling austenite transformation to upper bainite, its mixture with lower bainite and martensite takes place. Transformations proceed during cooling and the crystallization of cast iron have been determined and the casting hardness has been presented.
10
Content available remote On the measurement of surface tension in binders used for moulding sands
Hutera B., Smyksy K., Drożyński D.
Archives of Foundry Engineering
|
2008
|
Vol. 8, iss. 2
55-60
EN
The surface tension of foundry binders is a very important parameter affecting the properties of a sand-binder system. Combined with other parameters, its value determines an outcome of the process of moulding sand preparation and the mechanical properties of the ready moulding composition. The problem of how to measure the surface tension of binders used in preparation of moulding sands is discussed only occasionally. Indirectly, the surface tension is characterised by the value of a contact angle, but it never means that these two parameters can be considered identical. Numerous methods are available and used at present to measure the surface tension, among others, the capillary rise method, the spinning drop method, the sessile drop method, the pendant drop method, the method of pulled out ring (or plate, or frame). There is also a rich variety of devices offered with different measuring methods. The devices are modern and represent a high level of the technical skill and art. Unfortunately, also their price is high. It is, however, possible to obtain the reliable results of the surface tension measurement using relatively simple methods, viz. the stalagmometric method and the capillary rise method. What is necessary are proper conditions of the measurement, directly related with the specific properties of binders. The present paper gives examples of the results obtained during measurement of the surface tension of some selected binders. Attention was drawn to the methods of taking measurements, and the obtained results were discussed and analysed. The possibilities of detemining the surface tension of the examined binders from the results of the contact angle measurements using the "sessile drop" and "pendant drop" methods were outlined.
11
Content available remote Dilatometric studies of plaster sandmix in raw and heat treated state
Pawlak M., Niedźwiedzki Z.
Archives of Foundry Engineering
|
2008
|
Vol. 8, iss. 3
145-148
EN
Results of dilatometric studies of bounded plaster sandmix applied in precision pressure below atmospheric casting, are presented in this paper. Sandmix composed of half-hydrate alpha-CaSO4ź2H2O with different parts of silica SiO2 was a subject of investigations. Silica is a factor weakening the influence of phase transformations on total distortion of the mould during heating and thus influences the accuracy of prepared cast. Experimental moulders of dimensions 735 made of plaster sandmix with silica fraction equal 30; 40; 50; 60 and 70% were used during studies. Sandmix was tested in raw state and after heat treatment changing the alpha-half hydrate into anhydrite II (CaSO4). It was demonstrated that addition of the silica at level about 50% influences most advantageously on dimension changes of heated sandmix by lowering dilatations 3 times in comparison with sandmix composed of pure alpha-half hydrate. The transformation of plaster structure into anhydrite II is also important - the shrinkability phase disappears and expansion similar to linear-like appears. It was determined that it is possible to obtain sandmix of small, stabile distortion on the way of appropriate selection of components and heat treatment parameters what improves dimensional and shape accuracy limits of the cast and significantly limits internal stresses in the mould eliminating risk of its cracking.
12
Content available remote Computer aided casting methoding of railway system
Dobosz S. M., Chojecki A., Skoczylas R.
Archives of Foundry Engineering
|
2008
|
Vol. 8, iss. 2
17-20
EN
Authors prepared the casting technology for the frog. Casting method has been verified by simulation, using MAGMASOFT technique. In multistep simulation it was found that the positioning of casting in the mould feeding and some details of construction must be changed. Finally authors have presented the optimised solution of the technology which eliminates the porosity of casting. Analyses of the distribution of the stress during solidification and cooling in the mould proves that the deformation of casting is acceptable.
13
Content available remote Typification in automated workstations for pressurised casting
Tresa D., Amrichova H.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 1
189-190
EN
Typification of automated workstations for technologies of pressure castings results in lowering of costs for their realisation, shortening realisation time, making their operation more effective and making the maintenance simplified. Typification also simplifies their integration into higher automation units (operation units, plants).
14
Content available remote The investigate of flow in direct extrusion process of heterogeneous materials flow
Patejuk A., Piwnik J., Gabrylewska M.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 2
157-162
EN
The results of experimental investigations were introduced in range of verification of model investigations results (in utilization of supplementary materials) with results of investigations on real materials are presented in this work. To this aim the matrix became constructed with interchangeable little eye made possible extrusion process of real materials at three reduction ratio: [lambda] = 1,5 1,75 and 2,0. Analysis of heterogeneous materials flow process shows, that of principle onto extrusion process exerts kind as well as a way distribution of entrance creators' materials batch. However size of strength of stamp pressure is determined by reduction ratio in main measure.
15
Content available remote The influence of organic fibre types on technological parameters in process of ceramic moulds making
Karwiński A., Młodnicki S., Meksa W., Woźnicki G.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 2
143-146
EN
The research being presented in this article has been set up with the aim of working out both the technology and starting up manufacturing process ( in which a new generation of ceramic slips is employed ) in "Armatura" precise foundry. There have been used "aqueous" Ekosil silicate binder and quartz ceramic material with addition of organic fibres for making slip in the new technological solution. In the presented research work has been achieved a quantitative and qualitative selection of composition for the ceramic slip. The selection has been based on testing of physico-chemical and technological qualities.
16
Content available remote Selection of material for cores hardened with carbon dioxide
Soiński M. S., Chmielarz P.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 2
107-110
EN
The work presents the investigation results concerning the bending and the tensile strength of specimens made of various types of core sands. The investigated core sands for bending tests have been prepared of silica sand from Nowogród Dobrzański and, alternatively, of H33 German sand, both containing a variety of binders, namely Carbophen 5692, Carbophen 7170, Carbophen 8178, Novatec 1000, or SuperEko 2000 phenolic resins, as well as water glass. The tensile strength has been investigated for specimens made of silica sand from Nowogród Dobrzański and the sand supplied by Hüttenes-Albertus Polska, both types bond with Carbophen 5692, Novatec 1000, or SuperEko 2000 resins. All specimens have been tested immediately after the CO2 hardening process, then after 1 hour and after 24 hours. It has been found that the type of sand grains significantly affects both the bending and the tensile strength. Furthermore, for each type of sand the best bending strength has been achieved for Carbophen 7170, Carbophen 8178, and Novatec 1000 resins, whereas the best tensile strength has been offered by specimens bond with Carbophen 5692 resin.
17
Content available remote Modelling of semi-liquid aluminium flow in extrusion
Skorulski G., Piwnik J.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 2
31-36
EN
Experimental modeling using substitute materials is usually a simply way to obtain satisfacted results. This kind of experiment is characterizing by low cost. The significant results may be quickly applying using theory of probability. The way of modelling the deformation mechanisms during extrusion of aluminium alloys in semi - liquid phase, the way of preparing samples and experimental technique has been analysed in the following work. On the ground of received results (i.e. registrations of consecutive process steps) the grid of the flow velocity vectors on a flat sample surface was done. It allowed to draw conclusions which one of the basic deformation mechanisms is dominant in particular stage of the process. The technique of measurement has been shown as well. Experiments are made using plasticine and rape oil as a substiute materials. Some kind of different variants have been investigated. To ensure that such model experiments provide useful information it is essential to select model materials and prepare samples that would exhibit (preferably at room temperature) similar behaviour and similar deformation mechanisms as those present during the actual deformation process of aluminium alloys in a semi-liquid state. In particular the FLS, SS and PDS mechanisms should be adequately reproduced.
18
Content available remote Influence of loading on wear of composite material FeAl-Al2O3
Patejuk A.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 2
15-18
EN
In the paper, the authors showed the results of studies on influence of production conditions on composite material properties during intermetalic phase Fe-Al reinforced by Al2O3 particles. It was assessed that the quantity, size and condition of the surface of applied reinforcement has a significant influence on properties of composite material. Improvement of tribologic properties and resistance to erosion wear of the material was noted together with decrease in size of the particles used as reinforcement of the composite material. The use of Al2O3 particles covered with nickel layer as reinforcement substantially improved properties of studied composite material.
19
Content available remote Ferrous alloys cast under high pressure gas atmosphere
Pirowski Z., Olszyński J., Gwiżdż A.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 1
107-112
EN
The main objective of this paper is describing the essence of the process of introducing nitrogen to the melt of ferrous alloys by application of overpressure above the metal bath. The problem was discussed in terms of both theory (the thermodynamic aspects of the process) and practice (the technical and technological aspects, safety of the furnace stand operation, and technique of conducting the melt). The novel technique of melting under high pressure of the gas atmosphere (up to 5 MPa) has not been used so far in the domestic industry, mainly because of the lack of proper equipment satisfyng the requirements of safe operation. Owing to cooperation undertaken with a partner from Bulgaria, a more detailed investigation of this technology has become possible and melting of selected ferrous alloys was conducted under the gas atmosphere at a pressure of about 3,5 MPa.
20
Content available remote Evaluation of wettability of binders used in moulding sands
Hutera B., Smyksy K., Drożyński D.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 1
103-106
EN
Binders used in moulding sand have the differential properties. One of the main parameters influencing on moulding sand properties is wettability of the sand grain by binding material. In the article some problems concerned with wettability evaluation have been presented and the importance of this parameter for quantity description of process occurring in system: binder- sand grain has been mentioned. The procedure of wetting angle measurement and operation of prototype apparatus for wettability investigation of different binders used in moulding sand have been described, as well as the results of wetting angle measurement for different binders at different conditions. The addition of little amount of proper diluent to binder results in the state of equilibrium reached almost immediately. Such addition can also reduce the value of equilibrium contact angle. The uniform distribution of binder on the surface of the sand grains and reducing of the required mixing time can be obtained. It has also a positive effect on the moulding sand strength.
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