Статті в журналах з теми "Foundry form"
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1
Shrivastava, Vivek, Sandeep Rao, Suhrid Dev, and T. Prashanth. "Comparsion of Foundry Properties of Traditional Foundry Sand and Microspheres." Applied Mechanics and Materials 217-219 (November 2012): 1903–7. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.1903.
Повний текст джерелаАнотація:
A case study of the comparison of the properties of conventional foundry sand and light weight cenosphere/microsphere particles has been undertaken. This analysis was initiated by the preparation of their respective specimens, followed by the actual testing of these samples. Properties such as Compression strength, Shear strength, Permeability and Hardness were determined. In addition the grain form and microstructure of the specimens prepared was also analyzed. This analysis clearly indicates the possibility of the usage of cenospheres as a replacement of foundry sand.
2
Sharke, Paul. "Lost & Foundry." Mechanical Engineering 122, no. 09 (September 1, 2000): 62–67. http://dx.doi.org/10.1115/1.2000-sep-3.
Повний текст джерелаАнотація:
This article focuses on an ancient art form exhumed by modern engineering tools that makes hyperefficient gas turbines. IGT makers, such as GE, Siemens Westinghouse, and Alstom Power, use Howmet’s blades and vanes in the “hot sections” of their gas engines. Extreme inlet temperatures and the promise of greater efficiencies keep Howmet engineers seeking ways to implement advanced cooling designs, higher- temperature alloys, and stronger airfoils. Developing directionally solidified crystals was an important step in the improvement of turbine blade strength—one taken over 30 years ago. For directionally solidified casting, both the mold and the metal are kept at similar temperatures, around 2700 or 2800°F. Aside from the technological leaps that have been made in lost wax casting to produce ever larger, stronger, hotter, and more complex IGT components, it is still very much an elemental process.
3
Hidayat, Taufiq, and Mastiadi Tamjidillah. "PENGARUH TEMPERATUR TUANG DENGAN JENIS MATERIAL Al PADUAN (RONGSOK WAJAN) TERHADAP KEKERASAN HASIL PENGECORAN EVAPORATIVE." Scientific Journal of Mechanical Engineering Kinematika 1, no. 1 (June 9, 2016): 47–58. http://dx.doi.org/10.20527/sjmekinematika.v1i1.86.
Повний текст джерелаАнотація:
The objective of this research is to know the effect of casting temperature with the kind of guide material AI alloy junk from pan on hardness (the evaporative foundry result). The recycling of used aluminum is an alternative to reduce the waste material from aluminum. Recycling is a way of processing used materials that is started with selection, collection, then the process of foundry to create a new product that is more valuable economical. Casting temperature is an variable that can effect the result of foundry where if the casting temperature is low, then there will be a quick freeze before the mold is completely filled. And if the casting temperature is too high, then shrinkage can occur anditheiporosity value may increase. This research used four casting temperature variations, namely: 650°C, 700°C, 750°C, and 800°C. The evaporative foundry method uses styrofoam pattern that is piled up into sand mold. The metal that is casted will form like styrofoam pattern. The resultiof casting temperature testing can effect on hardness.
4
Rahman, Syaiful, and Rudi Siswanto. "PENGARUH TEMPERATUR TUANG DENGAN JENIS MATERIAL PADUAN Al RONGSOK (KAMPAS REM PANCI) TERHADAP POROSITAS, KEKERASAN DAN STRUKTUR MIKRO HASIL PENGECORAN EVAPORATIVE." Scientific Journal of Mechanical Engineering Kinematika 4, no. 1 (June 13, 2019): 87–94. http://dx.doi.org/10.20527/sjmekinematika.v4i1.55.
Повний текст джерелаАнотація:
Recycling is a way of processing used materials that is started with selection, collection, then the process of foundry to create a new product that is more valuable economical. The objective of this research is to know the effect of casting temperature with the kind of guide material AI alloy junk from brake shoe and pan on porosity, hardness, microstructure (the evaporative foundry result). The recycling of used aluminum is an alternative to reduce the waste material from aluminum. Casting temperature is an variable that can effect the result of foundry where if the casting temperature is low, then there will be a quick freeze before the mold is completely filled. And if the casting temperature is too high, then shrinkage can occur and the porosity value may increase. This research used four casting temperature variations, namely: 650°C, 700°C, 750°C, and 800°C. The evaporative foundry method uses styrofoam pattern that is piled up into sand mold. The metal that is casted will form like styrofoam pattern. The result of casting temperature testing can effect on porosity, hardness, and microstructure.
5
Bussolesi, Micol, Giovanni Grieco, Alireza Eslami, and Alessandro Cavallo. "Ophiolite Chromite Deposits as a New Source for the Production of Refractory Chromite Sands." Sustainability 12, no. 17 (August 31, 2020): 7096. http://dx.doi.org/10.3390/su12177096.
Повний текст джерелаАнотація:
Chromite foundry sands, mixed with binding resins, are employed in the industry to form molds for high demanding casting of metals and steel. As there is no substitute, these sands highly contribute to placing chromium at the top value of the economic importance parameter in the EU classification of critical raw materials. Finding new sources to produce these sands can contribute to lowering its criticality. Chromite foundry sands must meet strict quality parameters, referred to as Cr2O3 content, Fineness Index, SiO2 content, and Acid Demand. The foundry chromite market is dominated by South Africa production deriving from layered intrusion chromite deposits. Chromite sands from ophiolite chromite deposits, normally used for the metallurgical-grade chromite market, were tested as an alternative starting raw material to produce chromite foundry sands. The study of the silicate impurities assemblage showed that its mineralogy strongly affects the result of the most crucial parameter, the Acid Demand. Ophiolite chromite with serpentine impurities should be depurated to a hardly affordable 0.31% SiO2 content to meet Acid Demand quality threshold, due to high reactivity of this silicate with the acid environment of the test. Those with olivine impurities require to be depurated to a much more easily affordable 2.11% SiO2 content. As a result, ophiolite chromite with an olivine dominated silicate assemblage can be used as an alternative source of chromite foundry sands.
6
Vitiaz, P. A., N. A. Svidunovich, D. V. Kuis, Yu A. Nikalaichyk, and S. I. Rovin. "Fullerenes and prospects of their use in foundry and metallurgical production." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 3 (September 10, 2021): 91–96. http://dx.doi.org/10.21122/1683-6065-2021-3-91-96.
Повний текст джерелаАнотація:
The article is devoted to a special nanostructured form of carbon – fullerenes; the discovery of which became one of the most important events in the field of physics in the 80s of the last century. The article discusses the issues of obtaining and using fullerenes and other nanostructured materials; including hybrid ones; in foundry and metallurgical production: for modifying casting alloys; binders and auxiliary molding materials; for obtaining ceramic and hybrid nanocomposites; and for other purposes. It also provides information on the creation and operation of the world’s leading research centers specializing in the synthesis and application of nanomaterials in metallurgy and foundry.
7
Kaczmarska, Karolina, Sylwia Żymankowska-Kumon, Łukasz Byczyński, Beata Grabowska, Artur Bobrowski, and Sylwia Cukrowicz. "Thermoanalytical studies (TG–DTG–DSC, Py–GC/MS) of sodium carboxymethyl starch with different degrees of substitution." Journal of Thermal Analysis and Calorimetry 138, no. 6 (November 2, 2019): 4417–25. http://dx.doi.org/10.1007/s10973-019-08892-4.
Повний текст джерелаАнотація:
Abstract The paper presents the results of thermal analysis of polymer material in the form of starch derivatives in the form of sodium carboxymethyl starch (CMS–Na) with degree of substitution (DS) in the range 0.2–0.9 for the preparation of foundry binder. In this work, the thermal behavior of the modified starch and qualitative assessment of degradation products released during pyrolysis were determined and comprised. The analysis of the course of progressive decomposition of the starch material under controlled heating in the range of 25–1000 °C in anaerobic atmosphere was based on the results of thermal analysis methods (TG–DTG–DSC) in combination with the results of pyrolysis–gas chromatography–mass spectrometry (Py–GC/MS). The detailed TG–DTG–DSC analysis allowed to determine and compare the temperature at which the process of decomposition of carboxymethyl starches sodium salts with different degrees of substitution begins and to determine the course of its degradation under conditions corresponding to the contact of the foundry binder in the form of starch material with liquid metal (conditions like in foundry mold). Thermogravimetric analysis shows that decomposition processes are multistage, and dehydration is the first step of decomposition. Moreover, TG–DTG–DSC analyses indicate that the thermal stability and the decomposition path of tested compounds depend on the DS. Results of Py–GC/MS studies showed that the formation of decomposition products (including cyclic and aromatic hydrocarbons) in a predetermined temperature range is lower in the case of CMS–Na with high DS.
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Bifano, Luca, Alice Fischerauer, and Gerhard Fischerauer. "Investigation of complex permittivity spectra of foundry sands." tm - Technisches Messen 87, no. 5 (May 27, 2020): 372–80. http://dx.doi.org/10.1515/teme-2019-0121.
Повний текст джерелаАнотація:
AbstractThis paper discusses impedance spectroscopy as a method to characterize different types of quartz sand, chromite sand, and mixtures of sand. Based on two types of measurement cells, the impedance spectra for various dry sands were measured. The spectra differ enough to allow the sands to be distinguished. The results were validated by extracting the relative permittivity from the impedance and comparing it to literature data. After that, the method could be applied with confidence to other material systems. The influence of moisture was investigated with two types of quartz sand, and typical mixtures of form sand, chromite sand, and regenerated (quartz) sand were studied. In each case, the sand composition had a distinct influence on the Nyquist plot of the impedance spectrum. Compared to results from a laboratory foundry system, the new method exhibits a much more systematic dependence on the sand composition. If one succeeds in describing the impedance spectra with an equivalent circuit model parameterized by only a few parameters, these parameters could be used to identify and classify sand mixtures in the field. This would allow one, for example, to implement feedback control strategies in foundry regeneration processes, which would stabilize the processes and improve the quality of the casting products.
9
Chien, Chun-Hsien, Chien-Chou Chen, Wen-Liang Yeh, Wei-Ti Lin, Cheng-Hui Wu, Fu-Yang Chen, Yi-Cheng Lin, et al. "Study Photo Imagable dielectric (PID) and non-PID on process, fabrication and reliability by using panel glass substrate for next generation interconnection." International Symposium on Microelectronics 2019, no. 1 (October 1, 2019): 000216–22. http://dx.doi.org/10.4071/2380-4505-2019.1.000216.
Повний текст джерелаАнотація:
Abstract In 1965, Gordon E. Moore, the co-founder of Intel stated that numbers of transistors on a chip will double every 18 months and his theory called the Moore's Law. The law had been the guiding principle of chip design over 50 years. The technology dimension is scaling very aggressively in IC foundry. For example, TSMC announced their 5nm Fin Field-Effect Transistor (FinFET) process technology is optimized for both mobile and high performance computing applications. It is scheduled to start risk production in the second half of 2019.[1] To overview the semiconductor supply chain included IC foundry, wafer bumping, IC carrier, PCB (Printed circuit board) and OSAT (oversea assembly and testing)… etc., the IC carrier and PCB technology dimension scaling are far behind than the IC foundry since many reasons for the traditional industry. The industry needs different kinds of breakthrough approaches for the scaling of via and strip line in next generation interconnection. Traditional organic substrates faces many challenges of warpage, surface roughness and material dimension stability issues for manufacturing and high density I/Os with very fine line interconnections. To breakthrough these challenges, the materials of glass carrier, new photo-imagable dielectric (PID) and advanced equipment were evaluated for the fine line and fine via interconnection. In the papers, there are many PID and non-PID materials were surveyed and compared for fine via (< 10μm) interconnection or low loss of high frequency application. The first candidate was chosen for redistribution layers (RDL) fabrication by using 370mm × 470mm glass panels. Semi additive process (SAP) was used for direct metallization on glass panel with different build-up dielectric materials to form daisy chain test vehicles. The process, fabrication integration and electrical measurement results of daisy chain showed good continuity and electric resistance in the glass panel substrate. The reliability of the thermal cycling test (TCT) and highly accelerated stress test (HAST) were evaluated as well in this study.
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Begendikova, Zhannur, and Amina Bukayeva. "APPLICATION OF ADDITIVE TECHNOLOGIES IN MODERN FOUNDRY PRODUCTION." Вестник КазАТК 117, no. 2 (June 18, 2021): 20–27. http://dx.doi.org/10.52167/1609-1817-2021-117-2-20-27.
Повний текст джерелаАнотація:
The paper studies and analyzes the use of additive technologies in modern foundry production, determining their innovative development to create new products with high quality, reliability and determining its competitiveness in the world market of machine-building products. The essence of SLS-technology is defined as follows: model material - polystyrene powder with particle size of 50-150 microns - is rolled by a special roller on the working platform installed in a sealed chamber with an inert gas atmosphere - nitrogen. The laser beam "runs" where the computer "sees" the "body" in the given section of the CAD-model, as if "shading" the section of the part, as it is done by the constructor with a pencil on the drawing. In this case the laser beam is a source of heat, under the influence of which sintering of polystyrene particles takes place (working temperature - about 120°С). SLA, Polyjet and DLP technologies are the most widespread for metal casting. The first method involves sequential "running" of the laser beam over the entire surface of the layer to be formed where the model "body" is in the cross section. The second method of curing is performed by a beam in the form of a line in the process of layer formation due to radiation from a controlled ultraviolet lamp. The third way implies illumination of the whole layer simultaneously by creating the so-called mask - a "photo" of the current CAD-model section. Thus, additive technologies in modern foundry production have radically reduced labor intensity and costs of creating new products, which have high quality and reliability indicators and determine their competitiveness in the global market of machine-building products.
11
Begendikova, Zhannur, and Amina Bukayeva. "APPLICATION OF ADDITIVE TECHNOLOGIES IN MODERN FOUNDRY PRODUCTION." Вестник КазАТК 117, no. 2 (June 18, 2021): 20–27. http://dx.doi.org/10.52167/1609-1817-2021-117-2-20-27.
Повний текст джерелаАнотація:
The paper studies and analyzes the use of additive technologies in modern foundry production, determining their innovative development to create new products with high quality, reliability and determining its competitiveness in the world market of machine-building products. The essence of SLS-technology is defined as follows: model material - polystyrene powder with particle size of 50-150 microns - is rolled by a special roller on the working platform installed in a sealed chamber with an inert gas atmosphere - nitrogen. The laser beam "runs" where the computer "sees" the "body" in the given section of the CAD-model, as if "shading" the section of the part, as it is done by the constructor with a pencil on the drawing. In this case the laser beam is a source of heat, under the influence of which sintering of polystyrene particles takes place (working temperature - about 120°С). SLA, Polyjet and DLP technologies are the most widespread for metal casting. The first method involves sequential "running" of the laser beam over the entire surface of the layer to be formed where the model "body" is in the cross section. The second method of curing is performed by a beam in the form of a line in the process of layer formation due to radiation from a controlled ultraviolet lamp. The third way implies illumination of the whole layer simultaneously by creating the so-called mask - a "photo" of the current CAD-model section. Thus, additive technologies in modern foundry production have radically reduced labor intensity and costs of creating new products, which have high quality and reliability indicators and determine their competitiveness in the global market of machine-building products.
12
Liu, Bai Xiong, and Li Na Zhang. "Casting Solidification Behavior of Bimuth in Free-Cutting Copper Alloy." Advanced Materials Research 189-193 (February 2011): 3941–44. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.3941.
Повний текст джерелаАнотація:
Effect of bismuth on the microstructure and performance of Cu-Se-Bi brass were studied. The microstructure analysis and fracture observation indicated that the content of bismuth has obvious effect on the foundry property of Cu-Se-Bi brass. The bismuth distributes on the boundary of α and β phrase and when the content of bismuth is below 1.0wt%,bismuth freezes on the phrase boundary in form of granule; when the content of bismuth amounts to 2.0wt%,bismuth presents in form of blocks; while when the content of bismuth is beyond 2.5wt%,bismuth lies on the phrase boundary in form of continuous films. The solidification mechanism of bismuth in Cu-Se-Bi brass was discussed through the thermodynamics analysis.
13
Stawowy, A., R. Wrona, M. Brzeziński, and E. Ziółkowski. "Virtual Factory as a Method of Foundry Design and Production Management." Archives of Foundry Engineering 13, no. 1 (March 1, 2013): 113–18. http://dx.doi.org/10.2478/afe-2013-0022.
Повний текст джерелаАнотація:
Abstract The paper outlines the methodology of virtual design of a foundry plant as a system. The most important stage in the procedure involves the development of a model defined as a set of data about the system. Model development involves two stages: defining the model’s architecture and specifying the model data in the form of parameters and input-output relationships. The structure is understood as configuration of machines and transport units, representing the sub-systems and system components. As the main purpose of the simulation procedure is to find the characteristics of the system’s behaviour, the merits of the iterative method involving analysis, synthesis and evaluation of results are fully explored.
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Bryll, Katarzyna, Agnieszka Deja, and Leszek Kaszycki. "Proposal of evaluating the foundry shrinkage of hybrid epoxy composites used in sea and land transport." AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, no. 12 (December 31, 2018): 62–65. http://dx.doi.org/10.24136/atest.2018.355.
Повний текст джерелаАнотація:
This work determines the effect of combining two reinforcement phase materials, with extreme mechanical properties, on volume shrinkage of hybrid epoxy based composites. The strenghtening material used for the research was material recycled due to the developing shipbuilding industry, which seeks to search for modern ways of waste management, arising during the dismantling of small vessels. The research material was created as a result of gravity casting into a semi-open form of epoxy resin matrix and reinforcement of fiber glass (in mass fraction of 1%), as well as polyurethane foam (in the proportion of 1% to 10% by mass).
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Olgovskii, S. Ya. "WANDERING CASTERS IN THE NORTHERN PONTIC REGION." Archaeology and Early History of Ukraine 36, no. 3 (June 15, 2020): 503–9. http://dx.doi.org/10.37445/adiu.2020.03.37.
Повний текст джерелаАнотація:
The paper deals with the tradition of wandering craft that is the work of foundry workers on the road. Due to the high technological effectiveness the production and processing of metals required high professionalism which determined the isolation of the speciality of foundry workers and their difference from the rest of the population. They did not engage in other types of economic work and spread their influence over large areas, moving between settlements. Their activity is evidenced by burials in the Bronze Age far from settlements, accompanied by accessories of foundry craft, as well as treasures of the Late Bronze Age containing foundry moulds, tools and metal blanks, scrap and semi-finished products. Indirect traces of foundry craft in agricultural settlements are also frequent. They are represented by worn-out casting moulds or their fragments that were no longer of value to the artisan, or traces of working with metal in the form of semi-finished products or copper slags. Wandering craftsmen existed throughout the history of metallurgy from the emergence of this craft and almost until modern times, that is, from the Neolithic, the Bronze Age and the Early Iron Age to the 20th century, which made it possible to single out specialized metalworking centres, whose craftsmen provided the agricultural population with their products, wandering between settlements. At the same time, only two stationary workshops in the Northern Pontic region are known in the Bronze Age. But when isolating a metalworking centre, the presence of workshops is not at all necessary, since the focus does not mean a metalworking centre, but a region of similar production with common typological and chemical and metallurgical characteristics of products and a single technology for their production. It should only be noted that the question of wandering craftsmen in the early Iron Age has been raised quite recently, and by this time many well-developed metalworking centres are known. At the turn of the century, non-ferrous metal passes into the hands of jewellers and the role of non-ferrous metalworking decreases. Apparently, the role of wandering craftsmen is gradually decreasing. But an example of the work of a wandering craft has been only recently shown by nomadic gipsies.
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Achiţei, Dragoş Cristian, Petrică Vizureanu, Mirabela Georgiana Minciună, Mohd Mustafa Al Bakri Abdullah, and Ioan Gabriel Sandu. "Study on Al-Si Alloys Properties Enhancement." Applied Mechanics and Materials 754-755 (April 2015): 634–38. http://dx.doi.org/10.4028/www.scientific.net/amm.754-755.634.
Повний текст джерелаАнотація:
The paper presents a study about aluminum alloy, allied with Si, Cu, Mn, Mg. The Al-Si-Cu-Mg alloys for foundry are used for parts strongly required and which work at high temperatures, due to their good wear resistance. The industrial Al-Cu alloys contain 12 % cooper, are hipo-eutectic and may be for foundry or deformable. By alloying with magnesium, the Al-Cu alloys become with remarkable properties of resistance and plastic deformation processing. The improvement of mechanical characteristics for Al-Si alloys is realized with metals which forms the intermediate phases with silicon or aluminum, with variable solubility in solid state and which permits the structural hardening by heat treatments (quenching and ageing). From the analysis of dilatogramms, grouped for each sample, with the specific initial length, subjected to successive heating, from ambiance temperature up to 500°C, it is found that, with the appearance of ageing phenomena, on the samples aren’t significant modifications for elongation (few microns), only different may be the form of elongation-temperature curve. This analysis permits the determination of experimental data, regarding the behavior of Al-Si alloy subjected to heat treatments and repeated warming. Therefore, the Al-Si-Cu-Mg alloys, for foundry, are used for manufacture the parts strong required and which work at high temperatures, like pistons for engines with internal burn, parts for machines and reinforcements construction, due to their high usage resistance.
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Grabowska, Beata, Sylwia Żymankowska-Kumon, Sylwia Cukrowicz, Karolina Kaczmarska, Artur Bobrowski, and Bożena Tyliszczak. "Thermoanalytical tests (TG–DTG–DSC, Py-GC/MS) of foundry binders on the example of polymer composition of poly(acrylic acid)–sodium carboxymethylcellulose." Journal of Thermal Analysis and Calorimetry 138, no. 6 (November 7, 2019): 4427–36. http://dx.doi.org/10.1007/s10973-019-08883-5.
Повний текст джерелаАнотація:
Abstract The results of thermal analysis (TG–DTG–DSC) of a foundry binder from the BioCo group in the form of a polymer composition of poly(acrylic acid)–sodium carboxymethylcellulose (PAA/CMC-Na) are presented in this article. The range of temperature of degradation has been determined. It was found that as the temperature rises, physical and chemical changes take place in the binder as a result of evaporation of solvent water, release of constitutional water, intermolecular dehydration reactions and decomposition of polymer chains with the formation of gaseous decomposition products. Pyrolysis gas chromatography mass spectrometry method (Py-GC/MS) was used to identify PAA/CMC-Na binder degradation products in a predetermined temperature range based on the previously performed thermal analysis of TG–DTG–DSC. Py-GC/MS tests were also carried out to determine the emission level of gaseous products of the polymeric binder in the context of the processes occurring in the moulding (foundry) sand, in conditions of its contact with liquid metal. In addition, Py-GC/MS tests were carried out for two commonly used foundry binders based on alkaline phenolic resin cured with esters and based on urea-formaldehyde resin with furfuryl alcohol cured with sulphonic acids. The obtained Py-GC/MS results for commercial binders were referred to the results obtained for the new PAA/CMC-Na binder. It was found that the new polymer binder is characterized by the lowest emission level of gaseous products.
18
Shalevskaya, I. A. "Research of heat-exchange processes in a casting form with reinforcing phase." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 3 (October 16, 2019): 54–59. http://dx.doi.org/10.21122/1683-6065-2019-3-54-59.
Повний текст джерелаАнотація:
The method of lost foam casting with the reinforcing phase installed inside the polystyrene foam model is considered as a basic technological process. In The new multicomponent systems for the theory of foundry processes will be created in this case: «metal–model–implant–mold» and «metal–reinforcing phase–mold». The influence of the installed macroreinforcing elements in the form of steel rods on the heat and mass transfer was researched, solidification and hydrodynamics is investigated. The process was modeled using the ProCast program by evaluating the solidification conditions in the sand casting mold of cast samples from copper alloys and the reinforcing phase from carbon steel. To compare the results, the process of solidification of cast specimens with a size of 10×200 mm without a reinforcing phase and with a reinforcing phase in the form of rods occupying 20 and 50% of its cross section area was modeled. The research results are presented in the form of graphical curves of the cooling temperature and time. It has been established that the use of a reinforcing phase in a casting mold has a significant impact on the removal of metal overheating due to the consumption of a certain amount of heat for heating the reinforcing phase, increases the rate of alloy hardening and casting cooling.
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Arutyunyan, J. I. "Lost parks of Saint Petersburg: role of Italian garden in development of Foundry part." Vestnik of Saint Petersburg State University of Culture, no. 2 (31) (June 2017): 151–54. http://dx.doi.org/10.30725/2619-0303-2017-2-151-154.
Повний текст джерелаАнотація:
Italian garden occupied a vast area between Fontanka river and Ligovsky prospect. Vanished from the map of Saint Petersburg, it formed the layout of this zone. Public and residential buildings constructed in the 19th–21st centuries, form the structure of this space, a small area of garden retained the general regularities of structure of park of the 18th century. A reference to the original construction and the name of the territory became the modern quarter.
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Cukrowicz, Sylwia, Paweł Goj, Paweł Stoch, Artur Bobrowski, Bożena Tyliszczak, and Beata Grabowska. "Molecular Dynamic (MD) Simulations of Organic Modified Montmorillonite." Applied Sciences 12, no. 1 (December 29, 2021): 314. http://dx.doi.org/10.3390/app12010314.
Повний текст джерелаАнотація:
This study complements the knowledge about organobentonites, which are intended to be new binders in foundry technology. In the developed materials, acrylic polymers act as mineral modifying compounds. Modification of montmorillonite in bentonite was carried out in order to obtain a composite containing a polymer as a lustrous carbon precursor. The polymer undergoes thermal degradation during the casting process, which results in the formation of this specific carbon form, ensuring the appropriate quality of the casting surface without negative environmental impact. The present paper reports the results of computational simulation studies (LAMMPS software) aimed at broadening the knowledge of interactions of organic molecules in the form of acrylic acid and acrylate anions (from sodium acrylate) near the montmorillonite surface, which is a simplified model of bentonite/acrylic polymer systems. It has been proven that the –COOH group promotes the adsorption of acrylic acid (AA) to the mineral surface, while acrylate ions tend to be unpredictably scattered, which may be related to the electrostatic repulsion between anions and negatively charged clay surfaces. The simulation results are consistent with the results of structural tests carried out for actual organobentonites. It has been proven that the polymer mainly adsorbs on the mineral surface, although it also partially intercalates into the interlayer spaces of the montmorillonite. This comprehensive research approach is innovative in the engineering of foundry materials. Computer simulation methods have not been used in the production of new binding materials in molding sand technology so far.
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Lechner, Philipp, Georg Fuchs, Christoph Hartmann, Florian Steinlehner, Florian Ettemeyer, and Wolfram Volk. "Acoustical and Optical Determination of Mechanical Properties of Inorganically-Bound Foundry Core Materials." Materials 13, no. 11 (June 3, 2020): 2531. http://dx.doi.org/10.3390/ma13112531.
Повний текст джерелаАнотація:
Inorganically-bound sand cores are used in many light-metal foundries to form cavities in the cast part, which cannot be realised by the mould itself. To enable FEM simulations with core materials, their mechanical properties have to be measured. In this article, we adapt methods to determine the Young’s and shear modulus, the Poisson ratio and the fracture strain of sand cores. This allows us to fully parametrise an ideal brittle FEM model. We found that the Young’s and shear modulus can be obtained acoustically via the impulse excitation technique. The fracture strain was measured with a high-speed camera and a digital image correlation algorithm.
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Dotsenko, Vadim, Viktoria Boichuk, Vadym Fedorenko, and Yevhenii Tsybulskyi. "OBTAINING OF LOCALLY OPTIMAL SOLUTIONS BY COMBINING PROPERTIES OF MIXTURES FOR FOUNDRY MANUFACTURE." EUREKA: Physics and Engineering 6 (November 30, 2018): 48–53. http://dx.doi.org/10.21303/2461-4262.2018.00795.
Повний текст джерелаАнотація:
The aim of research is establishment of the relationship between the various properties of the mixture with liquid glass and hardener for the foundry industry – survivability, compressive strength and crumbling. Such an interrelation in the form of an adequate functional dependence makes it possible to assess the quality of the mixture for its compliance with the specified requirements, without resorting to additional laboratory measurements. It is very important to evaluate its suitability for the manufacture of rods, in particular, to meet the stringent requirements of production. Using the combined procedure of active and passive experiments, a regression equation was obtained describing the dependence of the mixture survivability on compressive strength and crumbling. It has been established that compressive strength is a more significant factor influencing survivability compared to crumbling, and it is almost 3 times (а1=0.36>а2=0.13). Analysis of the resulting regression equation shows that both of these factors have a positive effect on the survivability of the mixture – with an increase in compressive strength and crumbling, the survivability increases. In part, this conclusion requires confirmation in relation to crumbling, since the fact of a positive effect on survivability may be in doubt. By applying the procedure of comb analysis to the obtained regression equation, in order to describe the response surface, locally optimal solutions are established in the form of a ridge line. This line represents the optimal combination of compressive strength and shedding in the sense of ensuring the maximum survivability of the mixture. The corresponding ratios can be used as a nomogram, which allows to evaluate the ratios of the desired properties of the mixture, if it is fundamentally important to assess its quality by a set of properties.
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Liu, Tao, Quan Bo Tang, and Jian Hua Zhao. "The Tendency of Oxide Inclusion on Magnesium Alloys Intake Manifold in Tilt Cast." Materials Science Forum 686 (June 2011): 367–70. http://dx.doi.org/10.4028/www.scientific.net/msf.686.367.
Повний текст джерелаАнотація:
The oxide inclusion formation tendency in tilting cast magnesium alloys intake manifold was studied by numerical simulation. Two different programs were used for results comparison. The results indicate that it was easier to form oxide inclusion when connecting foundry ladle with the junction panel of intake manifold instead of cavity resonator. The oxidation mixture is prone to appear at the ribs and outer wall of the four main air piles of the intake manifold. The formation of oxide inclusion would be influenced by the flowing state of the melt during casting process.
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Nowak, D., K. Granat, and B. Opyd. "Measurement of Electrical Properties as Effectiveness Appraisal of Microwave Absorption by Moulding and Core Sands Subject to Microwave Utilization." Archives of Metallurgy and Materials 59, no. 2 (June 1, 2014): 713–16. http://dx.doi.org/10.2478/amm-2014-0117.
Повний текст джерелаАнотація:
Abstract Within the research, carried-out were examinations of foundry rejects in form of waste moulding and core sands in order to determine effectiveness of the microwave utilization process. Presented are measurements of permittivity and loss tangent that determine behaviour of materials in electromagnetic field. Measurements were performed on a stand of waveguide resonance cavity that permits precise determination of the above-mentioned parameters with the perturbation method. Examination results of five waste moulding sands confirm that effectiveness of microwave utilization depends on electrical properties of the sandmixes (permittivity and loss tangent).
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Vdovin, K. N., A. A. Zaitseva, and N. A. Feoktistov. "Research of Properties and Structure of Boron-modified Roll-foundry Iron." Journal of Materials Science Research 5, no. 2 (February 23, 2016): 82. http://dx.doi.org/10.5539/jmsr.v5n2p82.
Повний текст джерелаАнотація:
<p class="1Body">The aim of the research is to determine the properties and the structure of boron-alloyed iron used for rolls production. It was found that boron can form different carbides in iron, which significantly improve both hardenability and microhardness. Iron borides Fe<sub>3</sub>(B,C) are also formed in cast iron as only 40% of carbon atoms in cementite matrix can be replaced by boron. Besides, boron influences the temperatures of structural constituents decomposition (increases the rate of cementite decomposition), it also decreases the temperatures of developing phase transformations. The research group determined the kinetics of martensite decomposition, which is formed when chilled cast iron is poured into a metal mold and then undergoes thermal treatment to the temperature of 400 °C. In the temperature range of 210 – 400 °C the main process is decomposition of the retained austenite into bainite, while in the temperature range of 400 – 500 °C, the main process is decomposition of martensite and forming a ferrite-cementite mixture. In order to get the necessary properties of the roll face, it is necessary to provide its thermal treatment (tempering), when it is heated to the temperature of 400 °C to avoid martensite decomposition, because otherwise in the process of roll operation it can result in crack formation. </p>
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Vdovin, K. N., A. A. Zaitseva, and N. A. Feoktistov. "Research of Properties and Structure of Boron-modified Roll-foundry Iron." Journal of Materials Science Research 5, no. 2 (February 23, 2016): 88. http://dx.doi.org/10.5539/jmsr.v5n2p88.
Повний текст джерелаАнотація:
<p class="1Body">The aim of the research is to determine the properties and the structure of boron-alloyed iron used for rolls production. It was found that boron can form different carbides in iron, which significantly improve both hardenability and microhardness. Iron borides Fe<sub>3</sub>(B,C) are also formed in cast iron as only 40% of carbon atoms in cementite matrix can be replaced by boron. Besides, boron influences the temperatures of structural constituents decomposition (increases the rate of cementite decomposition), it also decreases the temperatures of developing phase transformations. The research group determined the kinetics of martensite decomposition, which is formed when chilled cast iron is poured into a metal mold and then undergoes thermal treatment to the temperature of 400 °C. In the temperature range of 210 – 400 °C the main process is decomposition of the retained austenite into bainite, while in the temperature range of 400 – 500 °C, the main process is decomposition of martensite and forming a ferrite-cementite mixture. In order to get the necessary properties of the roll face, it is necessary to provide its thermal treatment (tempering), when it is heated to the temperature of 400 °C to avoid martensite decomposition, because otherwise in the process of roll operation it can result in crack formation. </p>
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Goltsova, M. V. "Hydrogen technologies in foundry and metallurgy: current state and perspectives (review)." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 4 (January 14, 2019): 145–54. http://dx.doi.org/10.21122/1683-6065-2018-4-145-154.
Повний текст джерелаАнотація:
The article presents an overview of achievements of hydrogen treatment of materials, – the field of materials science, which makes possible improvement of materials structure and properties with the help of a reversible hydrogen effect. Examples of the hydrogen technologies use in casting and metallurgy are shown. Thermohydrogen processing (THP) of titanium alloys consists of a number of successive operations: hydrogenation of the metal to specified concentrations, technological action on the metal, vacuum annealing to remove hydrogen from the metal to safe concentrations. THP allows plasticizing titanium alloys, increasing their antifriction properties. In welded joints of titanium alloys, the THP equalizes the plasticity of the welded joint and the base metal, increases the cyclic life of the products by 2–2.5 times. In the technologies of casting, the preliminary hydrogenation of a number of aluminum melts leads to an increase in the strength limit by 20–30%, and the relative elongation by 15–45%, and also increasing heat resistance after plastic deformation. With the help of hydrogen, it is possible to carry out controlled powdering of intermetallic compounds, to form nanostructures in materials, to accelerate the processes of chemical-thermal treatment, and to cause «artificial polymorphism» in metals that are not polymorphic by its nature.It is concluded that some of hydrogen technologies have already been commercialized, some are still waiting for wide use. In general, the prospects for the development of hydrogen processing of materials lie in the development of the application of metal– hydrogen systems, and international activity (in particular, schools and conferences), traditionally and regularly held on this topic, allow us to judge the intensive development of the theory and practice of hydrogen technologies.
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Martins, Maria Auxiliadora de Barros, Lucas Ramon Roque da Silva, Maria Gabriela A. Ranieri, Regina Mambeli Barros, Valquíria Claret dos Santos, Paulo César Gonçalves, Márcia Regina Baldissera Rodrigues, et al. "Physical and Chemical Properties of Waste Foundry Exhaust Sand for Use in Self-Compacting Concrete." Materials 14, no. 19 (September 28, 2021): 5629. http://dx.doi.org/10.3390/ma14195629.
Повний текст джерелаАнотація:
The reuse of waste in civil construction brings environmental and economic benefits. However, for these to be used in concrete, it is necessary a previous evaluation of their physical and chemical characteristics. Thus, this study aimed to characterize and analyze the waste foundry exhaust sand (WFES) for use in self-compacting concrete (SCC). Foundry exhaust sand originates from the manufacturing process of sand molds and during demolding of metal parts. It is a fine sand rich in silica in the form of quartz collected by baghouse filter. Characterization of WFES was conducted through laser granulometry, scanning electron microscopy (SEM) in the energy dispersive spectroscopy (EDS) mode, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and derivative thermogravimetry (DTG) techniques. The waste was classified as non-hazardous and non-inert, with physical and chemical properties suitable for use in SCC composition, as fine aggregate or mineral addition. Five mixtures of SCC were developed, in order to determine the waste influence in both fresh and hardened concrete. The properties in the fresh state were reached. There was an increase in compressive strength and sulfate resistance, a decrease in water absorption of self-compacting concrete by incorporating WFES as 30% replacement.
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Bubenkó, Marianna, György Fegyverneki, Dániel Molnár, and Mónika Tokár. "The effect of the excess Titanium content on the microstructure of Al – Si foundry alloys." International Journal of Engineering and Management Sciences 4, no. 1 (March 3, 2019): 12–20. http://dx.doi.org/10.21791/ijems.2019.1.2.
Повний текст джерелаАнотація:
Grain refining is an important technological step for the nucleus growth of the melt, in order to increase the number of nuclei, to improve mechanical properties (tensile strength, yield strength, hardness, elongation), feeding conditions and to decrease the tendency of hot tearing and the degree of sintering. [1][2] The aim of the experiments was the determination of the grain refining effects of titanium (Ti) addition in the form of AlTi5B1 master alloy to the examined alloys (AlSi7MgCu0.5 – AC 42 000, AlSi9Cu3Fe0.5 – 46 500; AlSi9Cu1 – AC 46 400). The results prove that the addition of small amount of master alloy has a favourable effect on the foundry practice.
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Locatelli, Jerry, and Guang Wei Liu. "Automated Metal Siphoning and Cast House Energy Consumption." Materials Science Forum 630 (October 2009): 61–69. http://dx.doi.org/10.4028/www.scientific.net/msf.630.61.
Повний текст джерелаАнотація:
The transfer of molten aluminium from the potline crucible to the holding furnace is receiving renewed attention as pressure to reduce energy wastage in the form of dross is heightened by the prospect of Emissions Trading. Siphoning has long been recognised as the most loss efficient method of metal transfer and now with the availability of fully engineered, automated systems which are safe and reliable in addition to reducing melt loss by 75%; this method is set to become the industry standard. This paper presents some examples of automated siphon transfer systems and demonstrates the benefits of siphoning in applications ranging from the largest smelters to the smallest of foundry applications.
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Илюшкин, Дмитрий, Dmitriy Ilyushkin, Наталья Жижкина, Natalya Zhizhkina, Екатерина Зенцова, and Ekaterina Zentsova. "VIRTUAL SIMULATION OF ROLLER SPUN CASTING." Bulletin of Bryansk state technical university 2016, no. 1 (March 31, 2016): 22–27. http://dx.doi.org/10.12737/18174.
Повний текст джерелаАнотація:
The work is devoted to the virtual simulation of a sheet roll working layer formation at a technological stage “casting-solidification”. To form a virtual model of a roller mould pouring and foundry solidification there was used a computer modeling system (CMS) which included initial and boundary conditions for a roller mould pouring process with highalloy cast iron in the field of centrifugal force action. The distribution of a metal working layer along an inner surface of a rotating mould at different technological parameters: mass of highalloy cast iron, its density, temperature and pouring velocity, temperature of metal and non-metal parts of a mould at the initial point of time, modes of rotation and conditions of mould cooling and others were investigated. It is established that under the influence of centrifugal forces a free surface of liquid melt obtains a parabolic form. The influence of basic technological parameters upon the vertex position of a paraboloid of revolution of highalloy liquid melt z0 is revealed. It is shown in the paper that it stipulates for the unevenness of a working layer value along a roller barrel. As a result of computations it is obtained that the value of a working layer at lower flanks of barrels is higher than that of upper sides. The average value of such an exceeding makes 0.012 m. As a result of a simulation analysis of a foundry formation process at different technological parameters it is determined that the distance increase between the vertex of a paraboloid of revolution and the metal area investigated raises the working layer evenness along a roller barrel 3.6 times. Hence, the increase of capacity for work of a rolling tool is expected. The results of investigations presented are basic for the works for the increase of centrifugal roller servicing characteristic increase.
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Rafferty, Conor, Mitul Dalal, Dan Davis, Brian Elolampi, Yung-Yu Hsu, Stephen Lee, Lauren Klinker, and Briana Morey. "Epidermal electronics for health and fitness monitoring." International Symposium on Microelectronics 2012, no. 1 (January 1, 2012): 000156–61. http://dx.doi.org/10.4071/isom-2012-ta53.
Повний текст джерелаАнотація:
Medical deployment of electronics is frequently hampered by boxy, rigid packaging. Biological tissues are soft and curved, while electronic components are hard and angular. The mechanical mismatch can be alleviated by re-packaging electronics in radical new form factors. MC10 has developed a technology platform using ultra-thin components linked with stretchable interconnects and embedded in low modulus polymers which provide an excellent match to biological tissues. The MC10 platform is based on packaging today's high-performance active components in new mechanical form factors. The platform has three key elements: thin silicon embedded in film for flexibility, silicon transfer from foundry CMOS wafers to polymer-coated carriers and flexible metallic interconnect on polymer. On-body and in-body applications are both well suited to the technology platform. Skin-mounted systems resemble electronic tattoos, and can be worn for extended periods without discomfort while providing continuous monitoring. Inside the body, instrumented catheters provide a practitioner with unprecedented electrical information about the interior of the heart.
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Kinzin, D. I., S. A. Levandovskiy, and O. N. Tulupov. "Analysis of Efficiency of Roll Pass Design Options for Roughing Stands of Section Rolling Mill." Solid State Phenomena 265 (September 2017): 1136–41. http://dx.doi.org/10.4028/www.scientific.net/ssp.265.1136.
Повний текст джерелаАнотація:
The analysis of two roll pass design options of ten roughing stands atOJSC “MMK” 370 rolling mill has been performed. The usage of a new form of the roll grooves will allow achieving higher durability of the rolls. Lesser rolls consumption will allow saving up to 800K rubles annually. More uniform load distribution by the stands will reduce the possibility of main mill lines equipment breakdowns due to the jumps of rolling torque in the most loaded non-equiaxial stands. Better contact conditions and higher billet stability at the input into equiaxial grooves will reduce the amount of metal clogging. Moreover, a changed strain diagram – with higher roll pass design efficiency factor – will increase the roll out of foundry production defects.
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Lattanzi, Lucia, Annalisa Fortini, Maverick Giovagnoli, Mattia Merlin, Stefano Pirletti, Stefano Morè Spreafico, and Gian Luca Garagnani. "Thermal Analysis for the Prediction of Grain Refinement: An Experimental Investigation on an AlSiMg Foundry Alloy." Materials Science Forum 941 (December 2018): 1029–34. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1029.
Повний текст джерелаАнотація:
Thermal analysis is widely used as a prediction tool for the quality of Al alloys before casting. In the present work, the effects of different grain refiners on the characteristic temperatures and on the grain size of α-Al phase were studied by thermal analysis and metallographic investigations. The response of an AlSiMg alloy towards grain refiners, added in form of rods and tabs, was investigated. In foundry practice, the fading phenomenon of grain refiners is well-known but not completely understood. For these reasons, the fading effect of each refiner at 60 minutes and 120 minutes holding times was also studied. Cooling curves and their derivatives were obtained during solidification of the alloys in a metallic crucible. Experimental data indicated the increase of the temperature associated with the nucleation of α-Al dendrites for the grain-refined alloys in comparison to the untreated ones. Simultaneously, a decrease in primary Al growth temperature, that led to the disappearance of the minimum temperature, were observed. Microstructural features revealed that an increase of 6 ÷ 7 °C of the nucleation temperature, compared to the not refined alloy, corresponds to a significant decrease in average grain size.
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Holtzer, M., D. Drożyński, A. Bobrowski, and J. Makselon. "Method of the Moulding Sands Binding Power Assessment in Two-Layer Moulds Systems / Metoda oceny wielkości siły wiązania mas w układzie form dwuwarstwowych." Archives of Foundry Engineering 13, no. 2 (June 1, 2013): 39–42. http://dx.doi.org/10.2478/afe-2013-0033.
Повний текст джерелаАнотація:
Abstract More and more foundry plants applying moulding sands with water-glass or its substitutes for obtaining the high-quality casting surface at the smallest costs, consider the possibility of implementing two-layer moulds, in which e.g. the facing sand is a sand with an organic binder (no-bake type) and the backing sand is a sand with inorganic binder. Both kinds of sands must have the same chemical reaction. The most often applied system is the moulding sand on the water-glass or geopolymer bases - as the backing sand and the moulding sand from the group of self-hardening sands with a resol resin - as the facing sand. Investigations were performed for the system: moulding sand with inorganic GEOPOL binder or moulding sand with water glass (as a backing sand) and moulding sand, no-bake type, with a resol resin originated from various producers: Rezolit AM, Estrofen, Avenol NB 700 (as a facing sand). The LUZ apparatus, produced by Multiserw Morek, was adapted for investigations. A special partition with cuts was mounted in the attachment for making test specimens for measuring the tensile strength. This partition allowed a simultaneous compaction of two kinds of moulding sands. After 24 hours of hardening the highest values were obtained for the system: Geopol binder - Avenol resin.
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Yang, Di Xin, Jing Pei Xie, Ai Qin Wang, and Wen Yan Wang. "Effects of Rare Earth La on Microstructures, Mechanical Properties and Sliding Wear Behavior of High-Aluminium Zinc Foundry Alloy ZA30." Applied Mechanics and Materials 117-119 (October 2011): 360–63. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.360.
Повний текст джерелаАнотація:
Abstract. In this paper,the effect of rare earth La on microstructures and properties of ZA30 alloy were studied . The result shows that The structure is refined and mechanical properties are improved by adding La to ZA30 alloy,the alloy have best structures and comprehensive mechanical properties when La content is 0.1%; Rich-La phases are metallic compound Cu2La,Al2La and LaZn and precipitate in blocky form ,its number and size increase with La; The abrasive resistance of ZA30 alloy is significantly improved when La is over 0.3%.
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Ignaszak, Z., and J.-B. Prunier. "Innovative Laboratory Procedure to Estimate Thermophysical Parameters of Iso-exo Sleeves." Archives of Foundry Engineering 17, no. 1 (March 1, 2017): 67–72. http://dx.doi.org/10.1515/afe-2017-0012.
Повний текст джерелаАнотація:
Abstract The paper is focused on properties testing of materials used in form of iso-exo sleeves for risers in ferrous alloys foundry. They are grainyfibrous materials, containing components which initiate and upkeep exothermic reaction. Thermo-physical parameters characterizing such sleeves are necessary also to fill in reliable databases for computer simulation of processes in the casting-mould layout. Studies with use of a liquid alloy, especially regarding different sleeves bring valuable results, but are also relatively expensive and require longer test preparation time. A simplified method of study in laboratory conditions was proposed, in a furnace heated to a temperature above ignition temperature of sleeve material (initiation of exothermic reaction). This method allows to determine the basic parameters of each new sleeve supplied to foundries and assures relatively quick evaluation of sleeve quality, by comparison with previous sleeve supplies or with sleeves brought by new providers.
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Bartocha, Dariusz, and Czesław Baron. "The Impact of the Melting and Pouring Process on the Quality of the Biggest Rocking Bell Called Vox Patris." Quality Production Improvement - QPI 1, no. 1 (July 1, 2019): 230–37. http://dx.doi.org/10.2478/cqpi-2019-0031.
Повний текст джерелаАнотація:
Abstract The paper describes the process of melting, metalworking and pouring the form of the world's largest 55-ton rocking bell called Vox Patris. The project was carried out by Pracownia Ludwisarska of Jan Felczyński from Przemyśl in cooperation with Rduch Bells & Clocks from Czernica and Metalodlew SA from Kraków. Comprehensive scientific and technical support of the project was provided by the Department of Foundry of the Silesian University of Technology. The bell is made of bronze, which is an alloy of copper and tin with a content of tin at the level of 20%. The foundry, where the melting and pouring process took place, had two 14 ton electric furnaces, 15 ton transport pouring ladle and a 60 ton collection ladle. Therefore, it was necessary to determine the minimum temperature of the pouring and the conditions for holding the liquid metal so that the metal from the first cast would not solidify before accumulating its total amount (four melts) (Bartocha and Baron, 2015; Bartocha and Baron, 2016). The study presents the tests of alloy properties and a series of computer simulations. Thanks to them the maximum and minimum permissible temperature of metal overheating has been determined (Bartocha, 2017). The final stage of the cast was the mold pouring process. The filling system was responsible for the correct performance of this process. This system comprised a tank (collector) under a doublestopper 60-ton main ladle, an eleven-meter tapping spout, an infusion tank and a downgate. The task of the gating system is uniform and continuous supply of liquid metal to the mold until it is completely filled. The unusual layout, that was used, required checking many factors. Various configurations of the system parameters have been tested based on the series of computer simulations (Czochlarski and Bukowski, 1935; Ignaszak, 1999).
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Eron'ko, S. P., M. Yu Tkachev, E. A. Ponamareva, and E. V. Oshovskaya. "Prospects of small capacity ca sting ladles transfer to stopperless casting of steel." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 76, no. 8 (September 3, 2020): 803–9. http://dx.doi.org/10.32339/0135-5910-2020-8-803-809.
Повний текст джерелаАнотація:
Despite encouraging results, obtained at pilot tests, attempts to substitute the stopper facilities by sliding gates at casting ladles of small capacity, used at foundries of machine-building plants, did not result in their implementation in industry. The problems of transferring casting ladles with a capacity of up to 10 tons to continuous casting of steel, due to the peculiarities of their operation under conditions of obtaining low-weight castings, were considered. Priority problems were noted, the successful solution of which will confirm the prospects of using slide gates in foundry. The main requirements for a steel tapping gate system of a casting ladle of small tonnage are as follows: autonomy of the power supply of the shutter drive, eliminating the need to move flexible hoses over a long distance along the working platform; guaranteed start of casting in normal mode without burning the channel with oxygen; the stability of the node pressing the refractory plates of the slide gate to high temperatures in the absence of forced air cooling; the possibility of an active influence on reducing the intensity of the process of overgrowing of the steel outlet of the ladle in the course of filling molds. As a constructive solution aimed at fulfilling the indicated conditions, it was proposed to use a balancer-type cartridge valve equipped with a modernized electromechanical actuator and auxiliary devices for starting casting in normal mode due to mechanical destruction of the crust at the entrance to the steel outlet channel, as well as heating its walls in the closed state when moving the ladle from one form to another. It was recognized that participation on a parity basis in the creation of a promising sliding gate system for foundry ladles with a capacity of up to 10 tons of several development organizations with practical experience in this technical field is worthwhile.
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Spyrka, M., R. Atraszkiewicz, and L. Klimek. "A new ceramic composite based on spherical aluminium oxide for auxiliary panels in high-temperature firing processes." Archives of Materials Science and Engineering 1, no. 101 (January 1, 2020): 5–14. http://dx.doi.org/10.5604/01.3001.0013.9501.
Повний текст джерелаАнотація:
based on a spherical form of aluminium oxide. It is intended to limit the occurrence of technological problems related to the appropriate selection of auxiliary refractory materials, such as cracking, high heat capacity and variable coefficient of thermal expansion. Design/methodology/approach: A composite ceramic material with the spherical form of aluminium oxide included allows to reduce mass and stabilize characteristics of dimensional changes as a function of temperature in auxiliary panels in high-temperature firing processes with typical manufacturing process of the ceramics, which is gravity casting, drying and high-temperature firing. Findings: The study showed that the quantitative share of the spherical form of Al2O3 in the volume of ceramic material has a major impact on its properties. An increased share of spheres translates into greater material porosity and lower matrix density but also, by reducing the cross-section, into decreased strength properties. In the case of the developed ceramic material, there is no visible trend of a decrease in the coefficient of thermal expansion with increasing temperature, which is the case with traditional ceramic materials. Research limitations/implications: The strength of presented composite isn’t good and constitutes a further direction of research and development of the material. Practical implications: Although decreased strength properties, the composite with no visible trend of a decrease in the coefficient of thermal expansion with increasing temperature could be used as panels in high-temperature firing processes. Originality/value: New ceramic foundry composite based on a spherical form of aluminium oxide for auxiliary panels in high temperature processes.
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Lourenço, Nuno, Henrique Santos, and Carlos Sá. "The Use of Sodium Silicate to Improve Wetting of Tungsten Carbide Powder with Ductile Iron." Materials Science Forum 587-588 (June 2008): 118–22. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.118.
Повний текст джерелаАнотація:
A tungsten carbide insert is produced during ductile iron foundry practice to increase the surface hardness of the material. The insert is ensured with the help of a critical quantity of a binder, around 3 weight percent of sodium silicate, previously mixed with the tungsten carbide powder. The binder is verified to form a film around the tungsten carbide particles and bridges amongst these enveloped particles; these films and bridges are replaced by the ductile iron melt during the molding cavity filling. After solidification, a sound inserted layer is formed, composed of tungsten carbide particles in a tungsten enriched cast iron matrix. In the absence of the binder addition to the tungsten carbide powder no inserted layer is produced. The surface hardness of the inserted test pieces is close to 500VHN/4.9N and the respective thickness is around 2.5 mm. The characterization of the effect of the sodium silicate in the mixture has been the main purpose of this work
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Foglio, E., Marcello Gelfi, Annalisa Pola, and D. Lusuardi. "Effect of Shrinkage Porosity and Degenerated Graphite on Fatigue Crack Initiation in Ductile Cast Iron." Key Engineering Materials 754 (September 2017): 95–98. http://dx.doi.org/10.4028/www.scientific.net/kem.754.95.
Повний текст джерелаАнотація:
Heavy-section ductile iron castings solidify under low cooling rates, giving the risk to form defects like non-metallic inclusions, microporosities and degenerated shapes of graphite that have a negative effect on fatigue resistance, favoring the crack nucleation. The aim of this work is to precisely identify the defects that most affect the fatigue behavior in heavy-section castings, in order to guide the foundry to take the proper countermeasures. For this purpose, fatigue rotating bending tests were carried out on specimens machined from small-scale samples opportunely cast to reproduce long solidification times. The fracture surface of broken samples were investigated by means of Scanning Electron Microscopy in order to identify crack initiation points and fracture mechanisms. Shrinkage porosities and spiky graphite were found to play the most important effect on crack nucleation, lowering the fatigue resistance of the castings, while chunky graphite just behaved as a preferential path for crack propagation.
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de Paulo Ferreira Marques Sobrinho, Vicente, José Roberto de Oliveira, Estéfano Aparecido Vieira, Victor Bridi Telles, Felipe Fardin Grillo, Jorge Alberto Soares Tenório, and Denise Crocce Romano Espinosa. "Assessment of the Addition of Electric Arc Furnace Dust in Hot Metal at Temperature of 1,350 °C." Materials Science Forum 820 (June 2015): 588–93. http://dx.doi.org/10.4028/www.scientific.net/msf.820.588.
Повний текст джерелаАнотація:
This research aims to assess the incorporation of mass of the electric arc furnace dust (EAFD) by addition in hot metal produced in a local foundry (1.78% Si) at a temperature of 1,350°C. The EAFD is from a steel mill producer of long steel. The EAFD was added in the form of briquettes. Previously, the EAFD was characterized using the following techniques: chemical analysis, size analysis, X-ray diffraction, scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) microanalysis. The achievement of fusion experiments in laboratory scale, took place in a vertical tubular furnace with temperature control. The fusion experiments to assess the incorporation of the EAFD mass used alumina crucibles. A flow of inert gas (argon) was maintained inside the furnace during the experiments. After cooling the furnace to room temperature, it was done the pig iron and the slag were weighed to do a mass balance to assess the efficiency of the experiments.
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Sersour, Zakia, and Lynda Amirouche. "Effect of Aging and Annealing Treatments on the Microstructural Behavior of Some Al-Si Based Alloys." Applied Mechanics and Materials 775 (July 2015): 152–59. http://dx.doi.org/10.4028/www.scientific.net/amm.775.152.
Повний текст джерелаАнотація:
Al-Si foundry Alloys, of eutectic and hypo-eutectic compositions, are largely employed in the automotive industry because of their enhanced mechanical properties, their good flow and their relatively low melting points. We investigate in the present contribution, two different groups of alloys namely the AS13 (Al-13%Si in weight) and the AS10G (Al-10%Si-0.35%Mg in weight). Our study comprises two main parts in which, two types of heat treatments have been carried out: (i) Industrial heat treatments and (ii) isothermal annealing at 400°C and 500°C. The samples were characterized by optical microscopy, scanning electron microscopy and micro-hardness measurements. The microstructural characteristics of these alloys are mainly determined by their concentration in additives such as Mg. The AS13 alloys microstructure is characterized by the distribution and form of the eutectic silicon particles, whereas the AS10G alloys one is essentially marked by the presence of dendrites, Mg2Si precipitates and some other intermetallic compounds. Most of these compounds and precipitates are formed after heat treatments. It was observed that some other compounds such as the iron-based intermetallics, which already form during solidification, where impossible to dissolve with solution treatment. These compounds were observed to prohibit Mg2Si precipitates formation due to Mg solute trapping.
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Mateos-Angulo, Sergio, Javier del Pino, Daniel Mayor-Duarte, Mario San-Miguel-Montesdeoca, and Sunil L. Khemchandani. "Single-Event Transients in an IEEE 802.15.4 RF Receiver for Wireless Sensor Networks." Sensors 20, no. 16 (August 6, 2020): 4399. http://dx.doi.org/10.3390/s20164399.
Повний текст джерелаАнотація:
This paper presents a procedure to analyse the effects of radiation in an IEEE 802.15.4 RF receiver for wireless sensor networks (WSNs). Specifically, single-event transients (SETs) represent one of the greatest threats to the adequate performance of electronic communication devices in high-radiation environments. The proposed procedure consists in injecting current pulses in sensitive nodes of the receiver and analysing how they propagate through the different circuits that form the receiver. In order to perform this analysis, a Complementary Metal Oxide Semiconductor (CMOS) low-IF receiver has been designed using a 0.18 μm technology from the foundry UMC. In order to analyse the effect of single-event transients in this receiver, it has been studied how current pulses generated in the low-noise amplifier propagate down the receiver chain. The effect of the different circuits that form the receiver on this kind of pulse has been studied prior to the analysis of the complete receiver. First, the effect of SETs in low-noise amplifiers was analysed. Then, the propagation of pulses through mixers was studied. The effect of filters in the analysed current pulses has also been studied. Regarding the analysis of the designed RF receiver, an amplitude and phase shift was observed under the presence of SETs.
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Kononchuk, Serhii, Oleksandr Skrypnyk, Volodymyr Sviatskyi, and Viktor Pukalov. "Investigation of the Effect of Slag Trap Design on Slag Delay Efficiency in the SolidWorks Flow Simulation Parametric Modeling Environment." Central Ukrainian Scientific Bulletin. Technical Sciences, no. 3(34) (October 2020): 108–17. http://dx.doi.org/10.32515/2664-262x.2020.3(34).108-117.
Повний текст джерелаАнотація:
The most common technology for the manufacture of metal parts and work pieces is casting. High-tech branches of mechanical engineering require the production of high-quality castings of complex configuration from modern alloys with a given chemical composition and mechanical properties. The analysis of the causes of slag inclusions and ways to prevent them showed that in addition to technological means related to quality preparation of metal before pouring, a significant role is played by quiet continuous pouring of metal and properly designed foundry system, including slag trap. However, the use of the most common foundry systems (braking, throttle, with centrifugal slag traps, rain, siphon) to increase the efficiency of slag retention is associated with increased metal consumption, and as a consequence, leads to an increase in the cost of casting. Conducting experimental research by varying the design of the slag trap leads to an increase in the number of field experiments, given their complexity, limited by great difficulties. On the other hand, computer flow modeling allows to study the influence of slag trap design on the flow rate of the melt at the design stage and significantly reduce the cost of introduction of new castings. In order to reliably capture slag and reduce the speed of movement of the melt in the foundries, which provides a smooth filling of the form with an alloy, but without additional costs of metal, the original design of the ribbed slag catcher is proposed. The results of parametric modeling of the melt flow in the channel of the ribbed slag trap showed a decrease in the flow rate along the cross-sectional height of the slag trap compared to traditional by 0.028 m / s or 14.5%. This allowed to reduce the length of the slag trap to the first feeder. The expected metal savings are 0.26%. The form made using a 3D model of the slag trap showed satisfactory molding ability. But the obtained research results are of a recommendatory nature and require practical verification in the production environment. In addition, by varying parameters such as the height of the ribs, the distance between them, the angle of inclination, we can obtain similar results for different castings of different alloys. Given all this, there is a need for further study of the impact of the design of the slag trap on the efficiency of slag retention.
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Dan, Olena, and Larysa Trofimova. "A Study of The Properties of Forming Mixtures Containing Polystyrene Wastes." Journal of Casting & Materials Engineering 5, no. 2 (June 9, 2021): 14–19. http://dx.doi.org/10.7494/jcme.2021.5.2.14.
Повний текст джерелаАнотація:
Expanded polystyrene is widely used as a material for packaging, in modern construction as a heat and sound insulation layer, in thermal insulation systems for buildings, as well as tanks and pipelines. It is additionally used in foundry engineering for the production of models which are gasified during the production of castings from ferrous and non-ferrous alloys under the contact with liquid metal. The use of expanded polystyrene products is associated with waste generation, both in production and in consumption. About 40–50 kg/person of polystyrene waste is generated per year. The peculiarity of polymeric wastes is their resistance to aggressive environments. They do not rot and the destruction processes in natural conditions proceed rather slowly, with the formation of harmful substances that poison the environment. Therefore, the problem of the processing of waste from polymeric materials is of great importance, not only from the standpoint of environmental protection, but also due to the fact that in conditions of a shortage of polymer raw materials, this waste becomes a powerful raw material resource. This article describes the prospects for recycling expanded polystyrene wastes in foundry engineering. In this work, the properties of molding and core sands containing a combined binder, consisting of a solution of expanded polystyrene wastes in turpentine and clay were investigated, and their main characteristics (weight during stretching and crumbling) were determined. Molding and core mixtures, which contain only a binder in the form of a solution of expanded polystyrene in turpentine, have a crude strength of not more than 0.01 MPa. The introduction of a mixture of clay in the amount of 2–3% allows a crude strength of the mixture of up to 0.05 MPa to be obtained. After drying, the investigated mixtures containing a solution of expanded polystyrene wastes and clay have a tensile strength of up to 2.1 MPa. Mixtures into which a solution of polystyrene wastes and clay was introduced have an insignificant gas capacity and satisfactory gas permeability.
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Mohamed, Benahmed, Dellal Abdelkader, and Hellal Benchaben. "Mobilite Du Plomb Et Du Zinc Issus De Retombees Atmospheriques Dans Le Sol : Cas De La Zone Industrielle De Tiaret, Algerie." European Scientific Journal, ESJ 12, no. 18 (June 29, 2016): 131. http://dx.doi.org/10.19044/esj.2016.v12n18p131.
Повний текст джерелаАнотація:
Study of heavy metals mobility in soil is a necessary step for making an accurate appraisal and quantitative evaluation of the extent of contamination, indeed, wet and dry atmospheric deposits, plays an important role in the cycle of semi-volatile contaminants (Vinogradova, 2000). Metallurgical industries release heavy metals into the atmosphere, these last, clump together to form fines particles suspended in the air, these metals can be transported by wind via aerosol or aqueous pathway and deposited in the soil. The main aim of this work was to study the mobility and fate of lead and zinc from atmospheric deposits in a contaminated soil from the foundry (ALFET) in the industrial zone of Tiaret (Western Algeria) and to determine the effect of physicochemical parameters of the soil on their mobility in the topsoil. The physicochemical analysis of soil samples have shown that zinc and lead levels contents in the surface layer soil (0-30cm) vary depending on the pH, total limestone (CaCO3). The obtained results clearly show the major effect of soil texture, the fine fraction (clay and sand).
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Podprocká, R., and D. Bolibruchová. "Iron Intermetallic Phases in the Alloy Based on Al-Si-Mg by Applying Manganese." Archives of Foundry Engineering 17, no. 3 (September 1, 2017): 217–21. http://dx.doi.org/10.1515/afe-2017-0118.
Повний текст джерелаАнотація:
Abstract Manganese is an effective element used for the modification of needle intermetallic phases in Al-Si alloy. These particles seriously degrade mechanical characteristics of the alloy and promote the formation of porosity. By adding manganese the particles are being excluded in more compact shape of “Chinese script” or skeletal form, which are less initiative to cracks as Al5FeSi phase. In the present article, AlSi7Mg0.3 aluminium foundry alloy with several manganese content were studied. The alloy was controlled pollution for achieve higher iron content (about 0.7 wt. % Fe). The manganese were added in amount of 0.2 wt. %, 0.6 wt. %, 1.0 wt. % and 1.4 wt. %. The influence of the alloying element on the process of crystallization of intermetallic phases were compared to microstructural observations. The results indicate that increasing manganese content (> 0.2 wt. % Mn) lead to increase the temperature of solidification iron rich phase (TAl5FeSi) and reduction this particles. The temperature of nucleation Al-Si eutectic increase with higher manganese content also. At adding 1.4 wt. % Mn grain refinement and skeleton particles were observed.
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Glotka, Alexander, and Vadim Ol’shanetskii. "Influence of alloying systems on the properties of single crystal nickel-based superalloys." International Journal of Materials Research 112, no. 10 (October 1, 2021): 794–99. http://dx.doi.org/10.1515/ijmr-2021-8328.
Повний текст джерелаАнотація:
Abstract The purpose of the investigation was to obtain the predictive regression models that help correct the calculation of the mechanical properties of single crystal nickel-based superalloys without conducting prior experiments. The paper considers the influence of alloying elements on their tendency to form phases in foundry nickel-based superalloys. Using the elements influence on the phase formation, the coefficient Kc’ of the ratio of alloying elements for this class of alloys was set for the first time. We have revealed the short correlation of the ratio Kc’ with the dimensional misfit of γ and γ’ crystal lattices. Also, a high probability to predict the misfit for multicomponent nickel systems is shown, which significantly affected the strength properties. The regression models of correlation dependencies on the dimensional γ/γ’- misfit were offered to predict the short-term and long-term limits of the strength of alloys. We determined the operating temperature at which the misfit value should decrease to zero. The structure stability should increase because of the structural stresses minimizing. This has a positive effect on strength and plastic properties.