Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 13

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  innowacyjne materiały
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Investment Casting of AZ91 Magnesium Open-Cell Foams
EN
The process of investment casting of AZ91 magnesium alloy open-cell porosity foams was analysed. A basic investment casting technique was modified to enable the manufacturing of magnesium foams of chosen porosities in a safe and effective way. Various casting parameters (mould temperature, metal pouring temperature, pressure during metal pouring and solidifying) were calculated and analysed to assure complete mould filling and to minimize surface reactions with mould material. The foams manufactured with this method have been tested for their mechanical strength and collapsing behaviour. The AZ91 foams acquired in this research turned out to have very high open porosity level (>80%) and performed with Young’s modulus of ~30 MPa on average. Their collapsing mechanism has turned out to be mostly brittle. Magnesium alloy foams of such morphology may find their application in fields requiring lightweight materials of high strength to density ratio or of high energy absorption properties, as well as in biomedical implants due to magnesium’s high biocompatibility and its mechanical properties similar to bone tissue.
PL
Rosnąca potrzeba wytwarzania innowacyjnych materiałów na bazie włókien naturalnych stawia nowe wyzwania dla przemysłu i nauki. W szczególności zagadnienie to dotyczy rozwiązań, w których procesy wytwórcze wiążą się z niskim nakładem energetycznym, co ma swoje pozytywne konsekwencje ekonomiczne. Przede wszystkim przejawia się korzystnym oddziaływaniem na środowisko naturalne i klimat.
EN
The foundry industry is looking for solutions that improve the quality of the finished product and solutions that reduce the negative impact of the industry on the natural environment [26]. This process leads to work on the use of new or previously unused materials for binders. Organic and inorganic foundry binders are replaced by renewable materials of plant origin to meet the requirements of both the foundry customers and the environmental and health and safety regulations. The aim of this work was to identify the applicability of renewable and organic malted barley binder in moulding sand technology. The influence of the malt binder content on dry tensile strength, dry bending strength, dry permeability, dry wear resistance and flowability were evaluated. The results show that the malted barley binder can be self contained material binding the high-silica sand grains. Selected mechanical properties of moulding sands were found to increase with an increase in binder content. It was observed that malted barley binder creates smooth bonding bridges between high-silica sand grains.
EN
Precision casting is currently motivated by high demand especially for castings for the aerospace, automotive and gas turbine industries. High demands on precision of this parts pressure foundries to search for the new tools which can help them to improve the production. One of these tools is the numerical simulation of injection process, whereas such software especially for investment casting wax injection, process does not exist yet and for this case must be the existing software, for alloys or plastic, modified. This paper focuses on the use of numerical simulations to predict the behavior of injected models of gas turbine blades segments. The properties of wax mixtures, which were imported into the Cadmould simulation software as a material model, were found. The results of the simulations were verified using the results of 3D scanning measurements of wax models. As a supporting technology for verifying the results was used the Infrared Thermography.
EN
In 2014 we finished research works involved in the development of a technology for manufacturing innovative ceramic-carbon foam filters for molten metal alloys filtration, which were financed by the National Centre for Research and Development (NCBiR) from INNOTECH programme resources. A batch of the filters produced in this technology was tested in practice in domestic cast steel and cast iron foundries. The trials were successful and foundries declared their intention to purchase the newly-developed filters for the current production of casts. This provided an incentive for “Ferro-Term” Sp. z o.o. to start design works on the prototype line for a serial production of these filters. At the same time, in co-operation with a scientific consortium, including the co-authors of the technology, i.e. the Institute of Ceramics and Building Materials, Refractory Materials Division in Gliwice, Institute for the Chemical Processing of Coal in Zabrze and Foundry Research Institute in Cracow, the company made a successful attempt to raise some funds for the necessary adaptation of the developed technology from the semi-technical to industrial scale from Intelligent Development Operational Programme. In the article we have presented information on the effects of works performed within the framework of the project entitled “Modernization and adaptation of the existing technological line for purposes related to technology verification and start-up of the production of innovative ceramic-carbon filters for molten metal alloy filtration”.
EN
In highly developed countries, a significant progress in the use of alternative and clean energy sources has recently been observed. The European Union has implemented a programme to build wind turbines. It is estimated that in the coming years, thanks to the support in tax and credit, the global energy will develop very intensively. Many components of the wind turbines are castings. The basic material used for these castings is ductile iron, which in this particular case must meet high requirements imposed by the operating conditions of wind turbines. Anticipating an increase in customer demand for this type of castings, Krakodlew SA has decided to modernize its foundry using the ability to obtain external financing. The ductile iron manufacturing technology is now being developed and adapted to the specific conditions of the foundry plant, including the melting process yielding cast material with the required chemical composition, the technology of moulding, and the conditions for possible secondary metallurgy, spheroidizing treatment and graphitizing inoculation. The fulfilment of the imposed conditions for the casting production demands the use of advanced casting technologies introduced to the manufacturing process. The development of technology to launch the production of ductile iron castings for the wind power industry was supported by The National Centre for Research and Development (NCBiR). This article presents part of research on the binding kinetics of furan resin sands and choice of their composition for moulds and cores to make heavy castings used as components of equipment for the wind power industry.
EN
This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new parameter of moulding sands is investigated. With the use of presented testing equipment it is possible to determine force kinetics and deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws, caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this property, presents methods of measuring and continues earlier research.
EN
The suspension of copper droplets in the slag is considered. The copper/slug suspension is delivered as the product from the direct-to-blister process which is applied in the KGHM – Polska Miedź (Polish Copper) S.A. factory. The droplets / slag suspension was treated by a special set of reagents (patented by the authors) to improve the coagulation process. On the other hand, the observations are made to estimate if the melting / reduction process in the furnace is sufficiently effective to avoid a remaining of carbon in the copper droplets. The coagulation process was carried out in the crucible (laboratory scale). However, conditions imposed to the coagulation / solidification process in the laboratory scale were to some extent similar to those applied usually in the industry when the suspension is subjected to the analogous treatment in the electric arc-furnace. Some suggestions are formulated how to improve the industrial direct-to-blister process.
EN
This study focuses on the ALPHASET process of mould making (Ester-Cured Alkaline Phenolic No-Bake). The cross – linking of alkaline phenolic resole resin by adding at least one kind of organic esters is the secondary popular system (after the technology of molding sands with furfuryl resins) with the advantages including low odour, virtually no smoke, easy to stripping, good finishing, low veining, minimal erosion, and very good hot strength. The phenolic resoles used in the system are prepared typically by reacting 30-55% formaldehyde solution with less phenol using a strong alkali catalyst, such as sodium hydroxide or potassium hydroxide at the temperatures of below 110oC (pH > 7). After removing parts of water this yields a thermal set phenolic resin solution with solid content 50-70%. In order to significantly increase strength and to improve the moisture and humidity resistance of sand mould, it is necessary to mix a little silence solution addition with resin binder (about 0.1 – 0.3% based on the amount of resin binder).
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).
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.
PL
Masy formierskie ze szkłem wodnym mają szereg charakterystycznych cech, wynikających bezpośrednio z właściwości szkła wodnego. Niewątpliwą zaletą tych mas jest fakt, iż są one ekologiczne, a spoiwo jest tanie i łatwo dostępne. Natomiast w świetle właściwości technologicznych wykazują pewne wady, które ograniczają ich szerokie wykorzystanie w odlewnictwie. Ich ujemną cechą jest mała wytrzymałość w pierwszej fazie utwardzania; proces utwardzania nie przebiega „do końca” i jest ponowie uaktywniany po zalaniu formy ciekłym stopem. Efektem tego jest zwiększenie wytrzymałości masy co jest przyczyną złej wybijalności mas z tym spoiwem. Wykazują one również małą podatność do regeneracji. Dlatego też poszukuje się sposobów wyeliminowania lub ograniczenia tych wad. W artykule przedstawiono metody poprawy jakości mas formierskich ze szkłem wodnym. Procesy te, w uproszczeniu, mogą przebiegać na drodze: modyfikacji składu osnowy masy formierskiej, sposobu jej utwardzania lub modyfikacji samego spoiwa. W metodach tych wykorzystywane są często najnowsze techniki oraz materiały nowej generacji.
EN
Moulding sands with water glass have several characteristic properties, resulting directly from the water glass properties. An undoubted good point of these moulding sands is the fact, that they are ecological and their binder is cheap and easily obtainable. However their technological properties indicate certain failures, which limit their wider application in foundry engineering. Their negative property is low strength in the first phase of hardening; their hardening process is not ‘fully finished’ and is reactivated after the mould pouring with liquid alloy. In effect the increased moulding sand strength is the reason of bad knocking out of moulding sands with this binder. They are also not easily susceptible to the reclamation treatment. Therefore, ways of eliminating or limiting of these faults are looked for. Some methods of improving the quality of moulding sands with water glass are presented in the paper. These processes, in simplification, can concern: modifications of moulding sand matrices, methods of their hardening or modifications of a binder itself. The most modern techniques and materials of the new generation are often applied in these methods.
13
Content available remote Recycling of plastics from stockpiles performed by means of low-pressure injection
EN
A viability analysis of manufacturing goods out of plastics, from stockpiles and municipal residues, has been carried out. The analysis pertains goods in the form of inserts manufactured in light molds of big-sizes, by means of low-pressure injection. The cost analysis of the investment and manufacturing suggests that those goods are not price-competitive, as compared to other ones used in similar situations. Exploitation analysis proves that the goods, used outdoors are easily damaged on the surface by UV exposure, temperature differences of 24-hour cycle, as well as by water and plants. Re-recycling, and especially, the grinding of the product poses another challenge in the future. An analysis of the environmental impact of energy acquisition during the manufacturing of those goods was also carried out. The analysis also pertains the method of identifying the type of raw-material, in the process of segregation that stems from the necessity of a complex content training of staff running waste segregation posts.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.