Browsing by Subject "casting"

Now showing 1 - 11 of 11

Access status: Open Access ,
An evaluation of the effect of ultrasonic degassing on components produced by high pressure die casting
(AGH University of Science and Technology Press, 2020) Silva López, Manel da; Bajusz, Attila; Pabel, Thomas; Petkov, Tose; Plantà, Xavier
Ultrasonic treatment is known to be efficient for aluminium melt degassing with the additional benefits of being both economical and environment friendly. This paper describes the effect of ultrasonic degassing on the preparation of an AlSi9Cu3(Fe) alloy for High Pressure Die Casting (HPDC). The degassing efficiency was assessed in terms of the indirect evaluation of the melt, by means of the reduced pressure test and the porosity evaluation of the cast parts. Additionally, the corresponding hydrogen content was estimated with an experimental equation reported in the literature. Ultrasonic degassing shows greater efficiency in terms of hydrogen removal from the melt than conventional N$_{2}$ + Ar lance bubbling. Components produced by HPDC without degassing, with ultrasonic degassing and with lance degassing, were analysed by computed tomography and by metallography. The results show that the components produced by HPDC after ultrasonic degassing have a similar porosity level to components degassed with conventional lance bubbling, both showing an important improvement over components produced without degassing treatment. Hardness values were similar for all different treatment conditions and well over the minimum value established for the alloy by the corresponding standard.
Access status: Open Access ,
An introduction to the problem of the conversion of structural components, including components manufactured by casting techniques
(2016) Czekaj, Edward; Pysz, Stanisław; Garbacz-Klempka, Aldona; Żuczek, Robert
Modern development of technology features not only dynamic changes aimed at improving the performance characteristics of structural components through the optimum selection of materials, adjustments in design, or upgrade of manufacturing processes, but also the increase of the economic impact resulting from these changes. All of these processes occur under one common name of conversion and have a simple or – more often complex character (due to the vast scope of changes introduced). This article examines some basic definitions related to the concept of conversion and its association with innovative and intelligent solutions currently applied in materials engineering. Due to a variety of problems, attention was focused on the core notions related to conversion. Basing on our own experience (i.e., on the experience of the Foundry Research Institute and AGH University of Science and Technology in Krakow) and also on foreign achievements in this particular field of knowledge (mainly coming from the US), the most interesting examples of the conversion of materials and design (in the authors’ opinion) were discussed with reference to the methods of manufacture and possible interactions.
Access status: Open Access ,
Computer modeling for the visualization and geometric reconstruction of artefacts from the casting workshop in Grzybiany
(2015) Garbacz-Klempka, Aldona; Rzadkosz, Stanisław; Stolarczyk, Tomasz; Kozana, Janusz; Piękoś, Marcin; Kwak, Zofia; Tenerowicz, Mieszko
The casting workshop in Grzybiany is one of the most important archaeological sites in regards to casting technology from the Bronze and Early Iron Ages. During the 'Grzybiany. Osada nadjeziorna z epoki brązu i żelaza' [Grzybiany. Lakeside settlement from the Bronze and Early Iron Ages] research, the structure of casting moulds was analyzed as well as the chemical composition and microstructure of one of the more-interesting metal artefacts found within the workshop. Based on this, geometric visualization was performed with the help of computer-modeling methods. For scientific, experimental, and educational purposes, reconstruction of a zoomorphic pendant was performed using the lost-wax method. Wax models injected into a matrix were used, along with fired ceramic (gypsum) moulds and a specially prepared modeling alloy that corresponds to the original material. In this way, a true replica of the original was obtained: technologically, structurally and chemically. Studies of production technology of the casting workshop dated back to the Bronze and Early Iron Age help to increase the knowledge of the mould-preparing technology and the alloys used. Modern tools and computer programs aid in the research of old technologies and help disseminate the results.
Access status: Open Access ,
Computer modelling of the ablation casting process and prediction of the strength properties of AC-42000 castings
(Wydawnictwa AGH, 2022) Małysza, Marcin; Puzio, Sabina; Major-Gabryś, Katarzyna; Głowacki, Mirosław; Wilk-Kołodziejczyk, Dorota; Kamińska, Jadwiga
The demand for castings with superior properties has compelled the development and optimization of manufacturing technologies. By further developing already known techniques, we are able to contribute to the introduction of new research possibilities. The article presents the methodology of conducting simulation tests of the gravity casting process into sand moulds with the use of ablation. The ablation technique consists in spraying water through evenly spaced nozzles onto a mould into which the liquid casting alloy has been poured. The conducted research focuses on an alloy from the group of Al-Si alloys. In order to compare the effects of different techniques, additional tests were carried out for gravity casting into sand and metal die moulds. At the same time, virtual experiments were conducted to develop a simulation methodology for ablation casting technology, taking into account mould degradation. Additionally, the possibility of predicting the final mechanical properties of various manufacturing technologies was tested. Destructive tests were carried out to determine the mechanical properties in the cast samples, as well as microstructure tests and secondary dendrite spacing. The results of the mechanical tests are compared with the predicted simulation properties.
Access status: Open Access ,
Design of new casting alloys of Al-Mg-Si-Mn system with alloying additions, its structure, and mechanical properties
(Wydawnictwa AGH, 2017) Bojko, Vìctorìâ; Czekaj, Edward; Warmuzek, Małgorzata; Mihalenkov, Kostântin Vìktoroviĉ
The strength of Al-Mg-Si-Mn casting alloy strongly depends on Mg content in solid solution and precipitation of strengthening phases. Alloys with the nominal composition AlMg5Si2Mn with addition of Li and Ti+Zr were studied by means of differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and energy dispersive X-Ray analysis (EDX). DSC measurements show that the eutectic melting temperature was about 595°C and it is higher than that of commercial A356 casting alloy. The macro- and microhardness tests show that in as-cast state hardness were higher than for A356 and continuously growth during artificial aging. TEM investigations reveal that during artificial aging three different precipitation types are forms in the alloy matrix. Two of them belong to the different structures of Mg?Si precipitates. Appearance of the third one identified as d'-Al?Li phase represent that Al-Mg-Si system can be successfully used for designing of Li-containing casting alloy which is not developed yet.
Access status: Open Access ,
Effect of additional alloying and heat treatment on phase composition and morphology in Al-Mg-Si-type casting alloy
(Wydawnictwa AGH, 2017) Bojko, Vìctorìâ; Czekaj, Edward; Warmuzek, Małgorzata; Mihalenkov, Kostântin Vìktoroviĉ
The structure of permanent mold and high pressure die castings of the AlMg5Si2Mn alloy after alloying with Li and Sc has been investigated by scanning and transmission electron microscopy, hardness and microhardness measurements, energy dispersive X-ray analysis. Three conditions, as cast, solution treated and aged, were investigated. It was shown that in as-cast state, the structure of an alloy having the nominal composition AlMg5Si2Mn consists of four phases: first - the Al based solid solution, second - the (Al) + (Mg?Si) eutectic, third - the primary Mg?Si crystals and fourth - the a-Al(Mn, Fe)Si phase. Similar phases were observed in the alloys containing Sc or Li. After two days of storing in an as-cast condition, the solid solution in all tested alloys decomposes and forms zebra-crossing shaped precipitates. TEM examinations revealed that these precipitates nucleate heterogeneously on dislocations. The solution treatment at 575.0°C results in spheroidization of the Mg2Si lamellas, dissolution of the precipitates and formation of a-Al(Mn, Fe)Si dispersoids, nucleating on the surfaces of Mg?Si lamellas. In the Sc containing alloys, the formation of Al?Sc was detected after 120 min soaking. Further heating resulted in the growth of these precipitates. Aging of the Al-Mg-Si alloys leads to an increase of hardness in all studied alloys. This effect is mainly related to precipitation strengthening, via solid solution decomposition and formation of b''-phase. In Li-alloyed specimens, plates of b Mg?Si phase were observed together with small cubic-shaped d' Al?Li precipitates.
Access status: Open Access ,
Mieszaniny żeliwiakowe
(Huta Pokój S. A., [1932]) Buzek, Jerzy
Access status: Open Access ,
New possibilities in thermal analysis of molding materials
(AGH University of Science and Technology Press, 2018) Svidró, Judit; Diószegi, Attila
Molding material-related studies within the research activities concerning foundry technology have always been limited despite the significant effect of molding mixtures on the quality of cast parts. One reason behind this trend is the difficulty in interpreting the results of such complex systems like molds and cores. This paper provides a new possibility for studying the heat-absorption performance of materials used as molding media in metal casting processes. By further developing the Fourier thermal analysis method of cores and molds introduced by earlier studies, the investigation of unbonded sand has become available. The heat-absorption properties of the components can be hereby separated and studied respectively. Thermal analyses were performed on sphere-shaped resin-bonded cores with various binder levels as well as on unbonded sand samples. The temperature data collected from two points of the samples were then used for the calculation of the novel thermophysical properties. The results revealed not only quantitative but qualitative differences in the characteristics of the binder decomposition processes, providing a deeper understanding on the thermal behavior of molding materials. The outcome of the research provides more accurate data, which is the key for the improved simulation of casting processes.
Access status: Open Access ,
Odlewnictwo : według wykł. prof. inż. Modzelewskiego : rok szk. 1925/26
(Studenci Wydziału Hutniczego Akademii Górniczej, 1926) Modzelewski, Józef
Access status: Open Access ,
Optimization of simulation model parameters for solidification of metals with use of agent-based evolutionary algorithm
(Wydawnictwa AGH, 2008) Kluska-Nawarecka, Stanisława; Smolarek-Grzyb, Agnieszka; Byrski, Aleksander; Wilk-Kołodziejczyk, Dorota
The finite elements method (FEM) is currently widely used for simulation of thermal processes. However, one of still unresolved problems remains proper selection of mathematical model parameters for these processes. As far as modelling of cooling casts in forms is concerned, particular difficulties appear while estimating values of numerous coefficients such as: heat transport coefficient between metal and form, specific heat, metal and form heat conduction coefficient, metal and form density. Coefficients mentioned above depend not only on materials properties but also on temperature. In the paper the idea of optimalization of simulation method parameters based on adaptive adjustment of curve representing simulation result and result obtained in physical experiment is presented along with the idea of evolutionary and agent-based evolutionary optimization system designed to conduct such optimizations. Preliminary results obtained with use of ABAQUS system available in ACK CYFRONET and software developed at AGH-UST conclude the paper.
Access status: Open Access ,
Reverse Engineering and Computer Modelling in Archaeometallurgy for the Reconstruction of Heritage Objects Using Precision Casting and 3D Printing
(AGH University Press, 2025) Marlicka, Karolina; Fijołek, Andrzej; Garbacz-Klempka, Aldona; Piękoś, Marcin
This article presents an interdisciplinary approach to the reconstruction of a copper-alloy artefact using reverse engineering techniques combined with modern digital and manufacturing technologies. The research was motivated by the need to better understand historical casting techniques while preserving the integrity of cultural heritage objects through non-destructive methods. The study integrates 3D scanning, CAD-based modelling, numerical simulations, investment casting, and metal additive manufacturing. The geometry of the artefact was captured using high-resolution 3D scanning, enabling the development of two CAD models: one representing the preserved state of the object and a second reconstructed model with the missing fragment digitally restored. Both models were used for numerical simulations of mould filling, solidification, cooling, and porosity formation performed in MAGMASOFT® 6.1, allowing the assessment of technological feasibility and defect formation. Based on the simulation results, physical replicas were produced using investment casting and selective laser melting. The obtained numerical and experimental results were compared in terms of geometry reproduction, surface characteristics, and predicted versus observed casting behaviour. The study demonstrates that the combination of digital reconstruction, simulation tools, and experimental manufacturing provides a reliable framework for analysing historical metallurgical processes. The proposed methodology supports both scientific interpretation and the practical reconstruction of heritage objects and can be applied to a wide range of archaeometallurgical studies.