Obiektem zainteresowania są metalowe materiały szkieletowe o regularnych komórkach otwartych. Analiza regularnych elementarnych komórek ułatwia projektowanie właściwości mechanicznych odlewów szkieletowych. Celem badań był dobór geometrii szkieletu aluminiowego do wytwarzania odlewów szkieletowych. Plan zaprojektowania rdzenia odlewu szkieletowego obejmował: podział rdzenia na najmniejsze powtarzalne elementy, wyznaczenie geometrycznych cech komórek szkieletu metalowego, wytypowanie modelu kształtowego odlewu próbnego. Zaproponowano trzy koncepcje kształtu pojedynczych komórek. Są to osiemnastościan z płaskimi ścianami, osicmnastościan o minimalnych oporach hydraulicznych przepływu metalu oraz czternastościan Kelvina. Na podstawie analizy geometrii pojedynczej komórki wyznaczono kształt rdzenia.
EN
Cast skeleton materials with regular opened cells were studied. The analysis of elementary regular cells enables to design mechanical properties of various materials used for skeleton cast ings. The main aim of this work was cell geometry selection for creation the skeleton castings. The schedule of skeleton cast core included: division of the core for the smallest reproducible elements, determine of the geometric characteristics of the metal skeleton cells, creation of the shape model of the test model. Three concepts for elementary cells were presented. There are: oktadekahedron-with flat walls, oktadekahedron about minimal hydraulic contumacies flows of metal and Kelvin's tetradekahedon. On base of elementary cell geometrical analysis the core shape was determined.
Celem pracy jest dobór składników masy rdzeniowej i opracowanie optymalnych proporcji między jej składnikami, umożliwiających zastosowanie powstałej w ten sposób masy do wykonania rdzenia ceramicznego odlewu szkieletowego o regularnych komórkach otwartych. Zaproponowano skład masy rdzeniowej do wytwarzania odlewu szkieletowego po optymalizacji proporcji jej składników. Przedstawiono geometrię i sposób wykonania rdzenia krystobalitowo - gipsowego.
EN
The main aim of this work is components of mass on core selection and optimal proportion between its components elaborations, this way bringing application of this mass execution skeleton casting with open cells regular. Composition of mass skeleton casting was presented. Geometry and method of core cristobalite - gypsum were presented.
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Celem pracy był dobór geometrii szkieletu i materiału rdzenia do wytwarzania metalowych materiałów szkieletowych o regularnych komórkach otwartych. Plan zaprojektowania rdzenia odlewu szkieletowego obejmował: podział rdzenia na najmniejsze powtarzalne elementy, wyznaczenie geometrycznych cech komórek szkieletu metalowego, wytypowanie modelu kształtowego odlewu próbnego. Zaproponowano trzy koncepcje kształtu pojedynczych komórek. Na podstawie analizy geometrii pojedynczej komórki wyznaczono kształt rdzenia. Przedstawiono krystabalitowo - gipsową masę formierską.
EN
The main aim of this work was cell geometry and material selection for skeleton castings. The core design plan enclosed core division into smallest repeateble elements, metal cell geometry determination and idetification of shape model for example casting. Three concepts for elementary cells were presented. On base of elementary cell geometrical analysis the core shape was determined.
In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of core by liquid metal at estability technological parameters. Below the assumptions and results of the initial simulated calculations are presented. The total number of the nodes in the casting was 1920 and of the connectors was 5280 what gave filling of 100% for the nodes and 99,56% for the connectors in the results of the simulation. Together it resulted as 99,78% of filling the volume of the casting. The nodes and connectors were filled up to the 30 level of the casting in the simulation. The all connectors were filled up to the 25 level of the casting in the simulation. Starting from the 25 level individual connectors at the side surface of the casting weren't filled up. The connectors weren't supplied by multi-level getting system. The differences of filling the levels are little (maximally 5 per cent).
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In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of composite skeleton casting and mould filling process (Fig. 4, 5, 6). The basic subject of the computer simulation was the analysis of ability of metal to fill the channels creating the skeleton shape and prepared in form of a core. Analysis of filling for each consecutive levels of the skeleton casting was conducted for simulation results and real casting. The skeleton casting was manufactured according to proposed technology (Fig. 5). Number of fully filled nodes in simulation was higher than obtained in experimental studies. It was observed in the experiment, that metal during pouring did not flow through the whole channel section, what enabled possibilities of reducing the channel section and pointed out the necessity of local pressure increase.
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Przedstawiono dobór geometrii odlewu szkieletowego przeznaczonego do badań modelowych, symulacji zalewania i krzepnięcia oraz własności mechanicznych. Porównano wpływ ciśnienia metalostatycznego stopu aluminium i żeliwa na zapełnianie wnęki formy odlewniczej. Przedstawiono różnice w technologicznych własnościach badanych stopów na wypełnienie wnęki formy. Wykazano wpływ innych czynników poza ciśnieniem na uzyskanie odlewu szkieletowego.
EN
In this work geometry selection for model skeleton casting was shown. This model was used for properties investigation and numerical simulation. Comparison of metalostatic pressure was conducted for Al alloy and cast iron. Influence of technological properties of studied alloys on cavity filling and skeleton casting creation was indicated.
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Purpose: of this paper is to present recent achievements in field of skeleton structures. The aim of this work is to show results of searching for mechanically and technologically advantageous micro- and macrostructures. Methods of microstructure controlling were described. Most important parameters of the manufacturing process were identified. Design/methodology/approach: The influence of internal topology to stress distribution was described with the use of computer simulations. Simulations of the mold filling processes were also carried out. Real experiments were performed to prove the simulation results. The Qualitative and quantitative metallographic analysis were also carried out. Findings: It was found that the octahedron shape of internal cell causes best stress distribution and that the skeleton castings are a good alternative for cellular materials such as metal foams, lattice structures and sandwich panels. Their structured arranged topology allows precise design of properties. Research limitations/implications: Casting methods used to manufacture materials such as described skeleton castings confirmed their usefulness. Not well known and used yet rheological properties of liquid metals allow obtaining shape complicated structures near to metallic foams but structured arranged. Practical implications: Technological parameters of the skeleton castings manufacturing process were developed. Without use of advanced techniques there is a possibility to manufacture cheap skeleton structures in a typical foundry. With use of advanced technology like 3D printing there are almost unlimited possibilities of the skeleton castings internal topologies. Originality/value: Three dimensional cast skeleton structures with internal topology of octahedron confirmed their usefulness as elements used for energy dissipation. Obtaining the homogenous microstructure in the whole volume of complicated shape castings can be achieved.