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EN
The paper presents an example of the application of vibratory machining for castings based on the results of visual testing. The purpose of the work is to popularize non-destructive testing and vibratory machining as finishing process, especially in the case of cast objects. Visual testing is one of the obligatory non-destructive tests used for castings and welded joints. The basic requirements concerning the dimensional accuracy and surface texture of cast components are not met if visible surface flaws are detected. The tested castings, which had characteristic traces of the casting process, were subjected to vibratory machining. The machining with loose abrasive media in vibrating containers is aimed at smoothing the surface and reducing or completely removing flashes. To complement the visual testing were also conducted research on the contact profilometer Taylor Hobson PGI 1200. Particular attention was focused on measuring the height of flashes and changes in the surface of smoothed details based on BNIF No. 359 touch-visual patterns. Based on the work, it can be concluded that vibratory machining allows for removal flashes and smoothing of the surface of aluminum alloy cast objects.
EN
The paper presents the results of investigations concerning the influence of gray cast iron modification on free vibration frequency of the disc casting. Three different chemical composition melts of gray cast iron were prepared in induction furnace. During gravity casting 0.05% and 0.3% mass of the Inolate modifier was added on stream of metal for changing graphite flakes in castings. Sound signal vibration of cast iron sample was registered by means on microphone for free vibration frequency measurements. Decreasing of free vibration frequency of modified cast iron in comparison with non modified castings was observed. Higher contents of modifier causes more decreasing of free vibration frequency. Cast iron with smaller contents of carbon and silicon have higher free vibration frequency in comparison with eutectic composition cast iron. Hardness of examined cast iron is lower when the more modifier is added during modification process. Free frequency is smaller with smaller Brinell hardness of disc casting. It was concluded that control of free vibration frequency of disc castings by means of chemical composition and modification process can improved comfort and safety of working parts.
EN
This article proposes to use abrasive waterjet cutting (AWJ) for deflashing, deburring and similar finishing operations in casting. The basic requirements concerning the dimensional accuracy and surface texture of cast components are not met if visible surface flaws are detected. The experiments focused on the removal of external flash from elements made of EN-GJL-150 cast iron. The method employed for finishing was abrasive waterjet cutting. The tests were carried out using an APW 2010BB waterjet cutting machine. The form profiles before and after flash removal were determined with a Taylor Hobson PGI 1200 contact profiler. A Nikon AZ100 optical microscope was applied to observe and measure the changes in the flash height and width. The casting surface after finishing was smooth, without characteristic sharp, rough edges that occur in the cutting of objects with a considerable thickness. It should be emphasized that this method does not replace precise cutting operations. Yet, it can be successfully used to finish castings for which lower surface quality is required. An undoubted advantage of waterjet cutting is no effect of high temperature as is the case with plasma, laser or conventional cutting. This process is also easy to automate; one tool is needed to perform different finishing operations in order to obtain the desired dimensions, both internal and external.
EN
The paper presents the production problems related to casting using precision casting methods. The essential adverse effect of the casting process is the presence of burrs understood as oversize material necessary to remove the next finishing operations. In addition, the surfaces of the cast often characterized by a porous structure. One of the methods to improve the smoothness of the area proposed by the authors is the use of vibro-abrasive finishing. This type of treatment is widely used in the treatment of finishing small objects as well as complex shapes. Objects in the form of casting in the first step was treated with aggressive deburring polyester matrix abrasive media. The second stage was polishing, with using smoothing porcelain media. The study evaluated the effect of vibro-abrasive machining typical cast on the basic parameters of the geometric structure of the surface. Observations using optical microscope Nicon Eclipse MA 200 compared changes in surface microstructure and the effect of deburring. Clearly we can say that vibro-abrasive machining an effective way of reducing the size of burrs, smoothing and lightening the surface of objects made by casting.
EN
The article presents chosen aspects of foundry engineering of the settlement dwellers, including the archaeometric characteristics and metal science analysis of the artefacts, as well as an attempted reconstruction of the production organization. Discovered in Szczepidło (Greater Poland), the foundry workshop is unique in Central European Bronze Age. This workshop foundry operated roughly XIV-XII Century BC. Its production is evidenced by the presence of markers of the whole production cycle: semi-finished and finished products, production waste, fragments of crucibles and casting ladles with traces of usage, and tools. On this basis the alloys and foundry technologies used have been described. The analysis of foundry technology of copper alloys in the settlement area was carried out by observing the surface and structure of the products, semi-finished artefacts and fragments of crucibles by applying optical microscopy (OM), confocal microscopy (CLSM) and X-ray radiography (RT). The investigations of compositions were made by means of the energy dispersive X-ray fluorescence spectroscopy (ED-XRF) and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray analysis system (EDS).
EN
The paper presents the results of research of impact strength of aluminum alloy EN AC-44200 based composite materials reinforced with alumina particles. The research was carried out applying the materials produced by the pressure infiltration method of ceramic preforms made of Al2O3 particles of 3-6mum with the liquid EN AC-44200 Al alloy. The research was aimed at determining the composite resistance to dynamic loads, taking into account the volume of reinforcing particles (from 10 to 40% by volume) at an ambient of 23°C and at elevated temperatures to a maximum of 300°C. The results of this study were referred to the unreinforced matrix EN AC-44200 and to its hardness and tensile strength. Based on microscopic studies, an analysis and description of crack mechanics of the tested materials were performed. Structural analysis of a fracture surface, material structures under the crack surfaces of the matrix and cracking of the reinforcing particles were performed.
EN
The paper presents the results of analyzes of gases emitted during exposure to high temperature foundry molding sands, where binders are organic resins. As a research tool has been used special gas chromatograph designed to identify odorous compounds including the group of alkanes.
EN
It is well-known that the better the control of the liquid aluminium allows obtaining of better properties. One of the most important defects that is held responsible for lower properties has been the presence of porosity. Porosity has always been associated with the amount of dissolved hydrogen in the liquid. However, it was shown that hydrogen was not the major source but only a contributor the porosity. The most important defect that causes porosity is the presence of bifilms. These defects are surface entrained mainly due to turbulence and uncontrolled melt transfer. In this work, a cylindrical mould was designed (Ø30 x 300 mm) both from sand and die. Moulds were produced both from sand and die. Water cooled copper chill was placed at the bottom of the mould in order to generate a directional solidification. After the melt was prepared, prior to casting of the DC cast samples, reduced pressure test sample was taken to measure the melt quality (i.e. bifilm index). The cast parts were then sectioned into regions and longitudinal and transverse areas were investigated metallographically. Pore size, shape and distribution was measured by image analysis. The formation of porosity was evaluated by means of bifilm content, size and distribution in A356 alloy.
EN
The paper presents results of measuring heat diffusivity and thermal conductivity coefficients of used green foundry sand in temperature range ambient – 600°C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements relationships of the measured properties were evaluated. It was confirmed that the obtained relationships are complex and that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured and solidified casting.
EN
The main aim of this study was to examine the compression-induced state of stress arising in castings of the guide grates during operation in pusher-type furnaces for heat treatment. The effect of grate compression is caused by its forced movement in the furnace. The introduction of flexible segments to the grate structure changes in a significant way the stress distribution, mainly by decreasing its value, and consequently considerably extends the lifetime of the grates. The stress distribution was examined in the grates with flexible segments arranged crosswise (normal to the direction of the grate compression) and lengthwise (following the direction of force). A regression equation was derived to describe the relationship between the stress level in a row of ribs in the grate and the number of flexible segments of a lengthwise orientation placed in this row. It was found that, regardless of the distribution of the flexible segments in a row, the stress values were similar in all the ribs included in this row, and in a given row of the ribs/flexible segments a similar state of stress prevailed, irrespective of the position of this row in the whole structure of the grate and of the number of the ribs/flexible segments introduced therein. Parts of the grate responsible for the stress transfer were indicated and also parts which play the role of an element bonding the structure.
EN
The objective of studies presented in this publication was structuring of research knowledge about the ADI functional properties and changes in these properties due to material treatment. The results obtained were an outcome of research on the selection of a format of knowledge representation that would be useful in further work aiming at the design, application and implementation of an effective system supporting the decisions of a technologist concerning the choice of a suitable material (ADI in this case) and appropriate treatment process (if necessary). ALSV(FD) logic allows easy modelling of knowledge, which should let addressees of the target system carry out knowledge modelling by themselves. The expressiveness of ALSV (FD) logic allows recording the values of attributes from the scope of the modelled domain regarding ADI, which is undoubtedly an advantage in the context of further use of the logic. Yet, although the logic by itself does not allow creating the rules of knowledge, it may form a basis for the XTT format that is rule-based notation. The difficulty in the use of XTT format for knowledge modelling is acceptable, but formalism is not suitable for the discovery of rules, and therefore the knowledge of technologist is required to determine the impact of process parameters on values that are functional properties of ADI. The characteristics of ALSV(FD) logic and XTT formalism, described in this article, cover the most important aspects of a broadly discussed, full evaluation of the applicability of these solutions in the construction of a system supporting the decisions of a technologist.
EN
This study shown possibilities of Rapid Prototyping techniques (RP) and metal casting simulation software (MCSS), including non inertial reference systems. RP and MCSS have been used in order to design and produce essential elements for artificial heart. Additionally it has been shown possibilities of Fused Deposition Modeling (FDM) technique and DodJet technology using prototyped elements of rotodynamic pump. MAGMASOFT® software allowed to verify the cast kit heart valves model. Optical scanner Atos III enabled size verification of experimental elements supplied by rapid prototyping together with metal casting elements. Due to the selection of ceramic materials and assessment of molten metal – ceramic reactivity at high temperatures together with pattern materials selection model it was possible to design, manufacture a ceramic mould for titanium based alloys. The casting structure modification has been carried out by means of high isostatic pressure technique (HIP). The quality assessment of the casting materials has been performed using X-ray fluorescence (XRF), ARL 4460 Optical Emission Spectrometer, metallographic techniques and X-ray computed tomography.
PL
W artykule przedstawiono wykorzystanie technik szybkiego prototypowania oraz programów do symulacji przepływów stopów odlewniczych, w tym w nieinercyjnych układach odniesienia, do projektowania, a następnie wykonania elementów sztucznego serca. Zaprezentowano kolejno technikę Fused Deposition Modeling (FDM) oraz technologię DodJet na przykładzie wykonania prototypowych elementów pomp wirowych. Program MAGMASOFT® pozwolił zweryfikować projekt zestawu odlewniczego zastawki serca. Zastosowanie skanera optycznego Atos III umożliwiło weryfikację wymiarów doświadczalnych elementów otrzymanych przy wykorzystaniu technik RP oraz elementów odlewanych. Dzięki doborowi materiałów ceramicznych pod kątem oceny ich reakcji z ciekłym metalem oraz doborowi mas modelowych możliwe było opracowanie doświadczalnych form ceramicznych przeznaczonych do odlewania stopów tytanu. Modyfikację struktury odlewów wykonano przy zastosowaniu obróbką techniką HIP. Ocenę jakości wykonanych odlewów przeprowadzono kolejno metodą mikrofluorescencji rentgenowskiej, emisyjnym spektrometrem optycznym, technikami metalograficznymi oraz rentgenowską tomografią komputerową.
13
Content available remote Zintegrowane wytwarzanie tarcz hamulcowych
14
Content available remote Operacje obróbkowe formy ciśnieniowej
EN
The present article deals with the possibility of using the reverse engineering method for the production of prototype molds by Patternless process technology. Article describes method how to obtain virtual model by using a 3D scanner. Article also explains principle of the Patternless process technology, which is based on the milling mold cavity using CNC machining equipment. The aim of the research is the use of advanced technologies that speed up and facilitate the process of production prototype mold. The practical result of the presented experiment is bronze casting, which serves as a foot rest bracket on historic bike.
EN
The paper presents results of measuring thermal conductivity of green-sand mould material and time of pure-copper plate castings solidification evaluated from cooling curves. During the experiments pure Cu (99,8 %) plate was cast into the green-sand moulds. Basing on the measurements it was stated that thermal conductivity of the moulding sand has complex temperature variability, especially during the water vaporization and the obtained dependence should be used in the numerical calculations to improve their accuracy.
EN
The article presents the scope of application of incremental Rapid Prototyping/Rapid Tooling (RP/RT) – VoxelJet methods to the process of manufacturing casting moulds and casts of gear. The additive Rapid Prototyping methods (SL, FDM, 3DP, JS) are predominantly used for the production of models and model sets for casting moulds. The Rapid Tooling methods, such as: VoxelJet, ZCast-3DP and ProMetalRCT, enable the fabrication of casting moulds in the incremental process. The application of the RP/RT methods in cast production makes it possible to speed up the prototype preparation process. This is particularly vital with elements of complex shapes. The time required for the manufacture of the model, the mould and the cast proper may vary from a few to several dozen hours.
PL
Szybko rozwijająca się gospodarka oraz ciągłe wzrastające wymagania klientów wymuszają na odlewniach nieustanną rywalizację o egzystencję i dalszy rozwój. Osiągnięcie tych dwóch podstawowych rzeczy, jest sprawą niezmiernie trudną. Zarząd odlewni staje przed skomplikowanymi decyzjami związanymi z maksymalizacją efektywności produkcji. Do takich decyzji należy m.in. wdrażanie nowych systemów czy też instrumentów zarządzania jakością. W artykule poddano analizie i ocenie system kontroli jakości odlewów oparty na kartach kontrolnych do pomiarów liczbowych [...].
EN
Rapidly growing economy and the continuous increasing demands of customers force on foundry companies the ceaseless rivalry for existence and further development. Achieving these two basic aims is extremely difficult matter. Management of foundry is faced with complicated decisions connected with maximization of the production effectiveness. Such decisions include, among others, implementation of new systems or instruments of the quality management. The article analyzes and evaluates the quality control system of casting based on control charts of measurements [...]
EN
Contribution gives an overview of knowledge about the method of centrifugal casting with orientate on Tekcast system. Company Tekcast Industries has developed a device for centrifugal casting, extending the area of production of castings or prototyping of metal or plastic. Materials suitable for the centrifugal casting with flexible operating parameters may include non-ferrous metal alloy based on zinc or aluminum or non-metallic materials such as polyester resins, polyurethane resins, epoxy resins, waxes and the like. The casting process is particularly suitable for a wide range of commercial castings and decorative objects.
EN
A comparative laboratory research on a special testing stand of casting materials erosive wear have been conducted in terms of assessing their tribological properties. Different types of carbon iron alloys have been used, as well as modified alloys (metallurgically) in order to increase their resistance to this type of wear. Results have been presented in the form of tables and graphs.
PL
Przeprowadzono laboratoryjne porównawcze badania materiałów odlewniczych w warunkach zużycia erozyjnego w aspekcie oceny ich właściwości tribologicznych z użyciem specjalistycznego stanowiska badawczego. Wykorzystano różne stopy żelaza z węglem; do badań tych użyto także stopy modyfikowane metalurgicznie i cieplnie w celu zwiększenia ich odporności na ten rodzaj zużycia. Wyniki badań zaprezentowano w postaci wykresów i tabel.
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