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  • 1.
    Andrews, Ian
    et al.
    Saint-Gobain Ceramics Hamilton.
    Dumaillet, Jean-Marc
    Saint-Gobain Ceramics Hamilton.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Direct flow simulations in pressed foundry filters2003Conference paper (Other academic)
  • 2.
    Andrews, Ian
    et al.
    Saint-Gobain Ceramics Hamilton - Canada .
    Dumaillet, Jean-Marc
    Saint-Gobain Ceramics Hamilton - Canada .
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Direct flow simulations in pressed foundry filters2003In: Ductile Iron News, no 3Article in journal (Other academic)
  • 3.
    Andrews, Ian
    et al.
    Saint-Gobain Ceramics Hamilton.
    Dumaillet, Jean-Marc
    Saint-Gobain Ceramics Hamilton.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Simulering av flödesförlopp genom Filter2003Conference paper (Other academic)
  • 4.
    Belov, Ilja
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Domeij, Björn
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Matsushita, Taishi
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    A thermal conductivity model for grey iron2023In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193Article in journal (Refereed)
    Abstract [en]

    Thermal conductivity is an important property for many iron cast components, and the lack of widely accepted thermal conductivity model for cast iron, especially grey cast iron, motivates the efforts in this research area. The present study contributes to understanding the effects alloy microstructure has on thermal conductivity. A thermal conductivity model for a pearlitic cast iron has been proposed, based on the as-cast alloy composition and microstructural parameters obtained at different solidification rates. According to the model, available parallel heat transfer paths formed by connected graphite flakes across eutectic cells are determined by the space between dendrite arms. The uncertainties both for model inputs and for validation measurements have been estimated. Sensitivity analysis has been conducted to result in better understanding of the model behaviour. The agreement between modelled and measured thermal conductivities has been achieved within 5% on the average for the investigated samples.

  • 5.
    Belov, Ilja
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Matsushita, Taishi
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Sundaram, Dinesh
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    A simulation and experimental methodology to evaluate conditions for gas penetration from FURAN sand core into a cast iron melt2023Conference paper (Refereed)
  • 6.
    Diaconu, Lucian Vasile
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Density variations at solidification of grey cast iron2023Conference paper (Refereed)
  • 7.
    Diaconu, Lucian Vasile
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Sjögren, Torsten
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Skoglund, Peter
    Scania CV AB.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    A molibdén hatása az öntöttvasak termomechanikus hőfárasztási tulajdonságaira.2013In: Banyaszati es Kohaszati Lapok - Kohaszat, ISSN 0005-5670, Vol. 146, no 1, p. 13-17Article in journal (Refereed)
  • 8.
    Diaconu, Lucian Vasile
    et al.
    Department of Metallurgical and Foundry Engineering, University of Miskolc, Hungary.
    Sjögren, Torsten
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Skoglund, Peter
    SCANIA CV AB Materials Technology, Södertälje, Sweden.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Influence of molybdenum alloying on thermomechanical fatigue life of compacted graphite irons2012In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 25, no 5, p. 277-286Article in journal (Refereed)
    Abstract [en]

    In this study four compacted graphite irons (CGIs) and one grey cast iron (FGI) were produced and tested in the laboratory. The molybdenum content of the four CGI grades was varied between 0 and 1··01 wt-%. The purpose of the investigations was to examine the effect of the different molybdenum contents of the CGI on the thermomechanical fatigue (TMF) behaviour. The TMF tests were performed by cycling a constrained specimen between 110 and 600°C. For every material three tests were performed on specimens machined from a ∅20 mm cylinder. Other tests were performed on specimens machined from ∅55 mm and ∅85 mm cylinders respectively. The tests showed that additions of molybdenum improved the fatigue resistance of CGI. It was observed that additions of molybdenum refined the pearlite and that the specimens with a finer metallic matrix had a higher TMF resistance.

  • 9.
    Diaconu, Lucian Vasile
    et al.
    University of Miskolc, Hungary.
    Sjögren, Torsten
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Skoglund, Peter
    Scania CV AB.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Stress relaxation of compacted graphite iron alloyed with molybdenum2013In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 26, no 1, p. 51-57Article in journal (Refereed)
    Abstract [en]

    In a previous study, the thermomechanical fatigue resistance of four compacted graphite irons (CGIs) and one grey cast iron was investigated. The molybdenum content of the four CGIs varied between 0 and 1.01 wt-%. It was observed that during thermal cycling, the maximum value of the compressive stress continuously decreased while the value of the maximum tensile stress continuously increased. The continuous decrease in compressive stresses showed that stress relaxation occurs at elevated temperatures during thermal cycling. The goal of the present investigation was to investigate the phenomenon of stress relaxation at elevated temperatures. The tests were performed at 350 and 600°C respectively. The results of the stress relaxation tests performed at 600°C showed the same trend observed at thermomechanical fatigue testing. The tests showed that additions of molybdenum improved the fatigue resistance of CGI by lowering the stress relaxation rate.

  • 10.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Evaluation of eutectic growth in grey cast iron by means of inverse modelling2003In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 16, no 1-3, p. 301-306Article in journal (Refereed)
    Abstract [en]

    Computer simulation of casting becomes a valuable tool for developing advanced materials and casting components. Recent investigations and validation work on simulated cast components reveal the necessity of reliable analyses methods to determine solidification behaviour and to extract parameters for kinetic models to use at simulation of complex cast iron materials.

    The paper will present an inverse modelling method for determination of eutectic growth. The method include an experimental part proper to investigate simultaneously the solidification at three different cooling rates while the cast material has the same metallurgical origin, and a computational part for calculation of grow kinetics. Validation of the inverse method is made together with simulation. The inverse modelling of eutectic growth in grey iron indicates that chemical composition, type and amount of inoculants and cooling condition are strongly influencing the eutectic growth condition and gives different eutectic growth coefficients. By invoking a generalized KJMA* equation, the shape of the growing eutectic interface can be predicted. Deviation from perfectly spherical growth in real solidification cases is the source of variation of eutectic growth coefficients. The results of the inverse model are valuable to simulate differences in solidification behaviour in differently treated grey iron melts.

    * KJMA is the abbreviation of the name of the famous scientists Kolmogorow, Johnson, Mehl and Avrami who developed and applied the equation.

  • 11.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Mechanical Engineering. Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Microstructure and tensile property simulation of grey cast iron components2004Report (Other academic)
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  • 12.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik.
    On microstructure formation and mechanical properties in grey cast iron2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A major user of cast components is the automotive industry, where the functionality of the components is related to environmental demands. Internal combustion engines are constantly being improved to emit less pollution. A vital part in this development is to increase the material properties of engine components during their life cycle. In particular, cylinder heads, cylinder blocks and piston rings for diesel engine are produced in grey cast iron. Cast iron is expected to be in use far into the foreseeable future, due to favourable properties and low production costs. This work has been devoted to study microstructure formation, the tensile properties of cast iron and to some extent defect formation.

    The microstructure develops during solidification and solid state transformations. An inverse thermal analysis method was developed to study the kinetics of the microstructure formation. The inverse thermal analysis used, the Fourier method, analyses the cooling curves of two thermocouples to study the solidification or transformation. To decrease experimental errors, simulations have been done and the cooling curves were analysed. The best results were obtained when the thermocouples were placed close to each other.

    With the help of the thermal analysis a time dependent and fading nucleation law of the eutectic cells was found to fit the experimental results best. The experiments were made by multiple thermal analyses, and six different types of inoculants were investigated. The eutectic growth behaviour during solidification was evaluated with inverse thermal analysis, and it was found that commercial inoculants not only affect the eutectic nucleation but they also control the eutectic growth rate.

    Models of densities and volume changes are an integral part of a microstructure simulation of cast irons. These models are important for the inverse thermal analysis and an understanding of the porosity and expansion penetration in cast iron.

    The tensile strength of grey cast iron has been discussed by examining the fracture mechanism of the material at failure. The ultimate tensile strength is a result of the intimate collaboration between the graphite flake and the primary phases. Several parameters, including the graphite morphology, carbon content, inoculation and cooling conditions influence the ultimate tensile strength by offseting the equilibrium between the major constituents, the graphite flakes embedded in the primary metallic matrix. A model to predict the ultimate tensile strength is developed based on the interpretation of the stress intensity behaviour in a eutectic cell.

    The models developed for nucleation, eutectic growth and prediction of tensile strength were introduced into a casting simulation program. Mould filling, solidificauon, microstructure development and tensile strength of a complex. shaped cylinder head were simulated.

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    Fulltext
  • 13.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Årsmöte IFTJKPG – innovativ gjuteriteknik2023In: Gjuteriet, E-ISSN 0017-0682, no 3, p. 10-11Article in journal (Other (popular science, discussion, etc.))
  • 14.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Björklind, Tobias
    Scania CV AB.
    Diószegi, Zoltán
    Volvo Powertrain AB.
    Surface Turbulence at Flow of Gray Cast Iron2011In: Key Engineering Materials, ISSN 1013-9826, E-ISSN 1662-9795, Vol. 457, p. 422-427Article in journal (Refereed)
    Abstract [en]

    Gray cast iron has been investigated with respect to surface turbulence during mould filling. Different levels of flow velocities have been provoked in a vertically parted sand mould. The thermal resistant transparent front side of the mould permitted the observation of the flow pattern due to high speed camera registration. The registered frames including the liquid surface were investigated using image analyses. The results show good correlation between the average flow velocity and the liquid iron surface extension. Consequently it has been demonstrated that an increased absorption of hydrogen and nitrogen during mould filling is dependent on the level of liquid surface turbulence.

  • 15.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diaconu, Lucian Vasile
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Advances in metallography and stereology of cast iron2023Conference paper (Refereed)
  • 16.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Diaconu, Lucian Vasile
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Microstructures and Characterization of Gray Irons2017In: ASM Handbook, Volume 1A: Cast Iron Science and Technology / [ed] Doru M. Stefanescu, Materials Park, Ohio: ASM International, 2017, p. 583-589Chapter in book (Refereed)
  • 17.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diaconu, Lucian VasileJönköping University, School of Engineering, JTH, Materials and Manufacturing.Jarfors, Anders E.W.Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Science and Processing of Cast Iron XI2018Conference proceedings (editor) (Refereed)
    Abstract [en]

    The goal of this book is to present for readers the articles from the 11th International Symposium on the Science and Processing of Cast Iron that was held in September 2017 in Jönköping, Sweden. The content of the book reflects the state of the art, research and development tendencies of cast iron as the main engineering cast material also in the 21st century.

  • 18.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Diószegi, Eva
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Diocore AB.
    Tóth, Judit
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Svidró, József Tamás
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Modelling and simulation of heat conduction in 1-D polar spherical coordinates using control volume-based finite difference method2016In: International journal of numerical methods for heat & fluid flow, ISSN 0961-5539, E-ISSN 1758-6585, Vol. 26, no 1, p. 2-17Article in journal (Refereed)
    Abstract [en]

    Purpose - The purpose of this paper is to obtain a finite difference method (FDM) solution using control volume for heat transport by conduction and the heat absorption by the enthalpy model in the sand mixture used in casting manufacturing processes. A mixture of sand and different chemicals (binders) is used as moulding materials in the casting processes. The presence of various compounds in the system improve the complexity of the heat transport due to the heat absorption as the binders are decomposing and transformed into gaseous products due to significant heat shock. Design/methodology/approach - The geometrical domain were defined in a 1D polar coordinate system and adapted for numerical simulation according to the control volume-based FDM. The simulation results were validated by comparison to the temperature measurements under laboratory conditions as the sand mould mixture was heated by interacting with a liquid alloy. Findings - Results of validation and simulation methods were about high correspondence, the numerical method presented in this paper is accurate and has significant potential in the simulation of casting processes. Originality/value - Both numerical solution (definition of geometrical domain in 1D polar coordinate system) and verification method presented in this paper are state-of-the-art in their kinds and present high scientific value especially regarding to the topic of numerical modelling of heat flow and foundry technology.

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  • 19.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Dugic, Izudin
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    The Mechanism of Metal Expansion Penetration in Gray Cast Iron2006Conference paper (Refereed)
  • 20.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Dugic, Izudin
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Metal Expansion Penetration on Concave Casting Surfaces of Grey Cast Iron Cylinder Heads2007In: Transactions of the American Foundry Society, Vol. 115, p. 609-615Article in journal (Refereed)
  • 21.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Dugic, Izudin
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Penetrationsfehler an konkaven Gussteiloberflächen von Grauguss-Zylinderköpfen (Penetration errors casting concave surfaces of grey cast iron cylinder heads)2007In: Giesserei-Praxis, ISSN 0016-9781, Vol. 58, no 11, p. 450-454Article in journal (Other academic)
  • 22.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Elfsberg, Jessica
    Scania CV AB, Södertälje, Sweden .
    Diószegi, Zoltán
    Volvo Group Trucks Operation, Skövde, Sweden.
    Solubility of Hydrogen and Nitrogen in liquid cast iron during melting and mold filling2016In: 72nd World Foundry Congress, WFC 2016, The World Foundry Organization (WFO) , 2016, p. 52-53Conference paper (Refereed)
    Abstract [en]

    Defect formation like gas- and shrinkage porosity at cast iron component production is related to the content of gaseous elements in the liquid metal. The present work investigate the solubility of hydrogen and nitrogen in liquid iron aimed for production of lamellar and compacted graphite cast iron. The used methods and instruments are a combination of commercial measuring devices and novel experimental assemblies for measuring solubility of hydrogen and nitrogen during melting and mold filling of a complex shaped cast component. The obtained results reveal the role of the charge material and the mold filling on the solubility of the investigated elements. 

    Download full text (pdf)
    fulltext
  • 23.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Elfsberg, Jessica
    Scania CV AB, Södertälje, Sweden.
    Diószegi, Zoltán
    Volvo Group Trucks Operation, Skövde, Sweden.
    Ramos, André Koerich
    TUPY S.A., Joinville, Brazil.
    Shrinkage porosity formation in cast iron components2018In: 73rd World Foundry Congress "Creative Foundry", WFC 2018 - Proceedings, Stowarzyszenie Techniczne Odlewnikow Polskich/Polish Foundrymen's Association , 2018, p. 207-208Conference paper (Refereed)
    Abstract [en]

    Shrinkage porosity formation mechanisms at production of cast iron components is particularly complex and became more and more difficult to understand since the shape casting complexity have been increased more and more in advanced component applications. The present work intends to summarize the state of the art in understanding the shrinkage porosity formation mechanism of cast iron based on a series of key publications, MSc and PhD theses performed in collaboration between cast iron component users, producers and researchers.

  • 24.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Elmquist, Lennart
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Orlenius, Jessica
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Dugic, Izudin
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Defect Formation at Casting of Gray Iron Components2009In: Proceedings of the Carl Loper Cast Iron Symposium, Madison, Wisconsin, US, 2009Conference paper (Refereed)
  • 25.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Elmquist, Lennart
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Orlenius, Jessica
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Dugic, Izudin
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Defect Formation of Gray Iron Casting2009In: International Journal of Metalcasting, ISSN 1939-5981, Vol. 3, no 4, p. 49-58Article in journal (Refereed)
    Abstract [en]

    Cast iron is one of the oldest technical alloys used for creating objects. Foundrymen from the very beginning of casting was fighting to avoid casting defects. In the beginning a successfully performed casting was associated with witchcraft. Cast component producers suffer yearly substantial expenses due to rejecting or repairing castings. The present work will summarize research efforts to understand formation mechanisms of defects, performed in collaboration with Swedish foundries during the last years. The presented work will focus on defects, specific casting of gray iron components. Studied defects are gas porosity, shrinkage porosity and metal expansion penetration. Novell experimental set up has been developed or existing methods has been improved to study defect formation mechanisms. Today we can realize that casting without defects are possible only by approaching the defect formation mechanism with multidisciplinary science.

  • 26.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Swerea Swecast, Sweden.
    Diaconu, Lucian Vasile
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Prediction of volume fraction of primary austenite at solidification of lamellar graphite cast iron using thermal analyses2016In: Journal of thermal analysis and calorimetry (Print), ISSN 1388-6150, E-ISSN 1588-2926, Vol. 124, no 1, p. 215-225Article in journal (Refereed)
    Abstract [en]

    Lamellar graphite cast iron was investigated with carbon equivalents varied between CE = 3.4 and 4.26, cast at various cooling rates between 0.195 and 3.5 °C s−1 covering the limits used for technical applications in the production of complex-shaped lamellar graphite cast iron. Registered cooling curves displaced in two positions in the casting were used to predict the solidification and microstructure formation mechanisms. The predicted volume fraction of primary austenite was compared with the fraction of primary austenite measured on colour micrographs with the help of image analyses. A good correlation has been obtained for medium and slow cooling conditions, while a less good correlation at fast cooling condition was attributed to the used protective environment to preserve thermocouples. The observed fraction and the predicted fraction of primary austenite were in good correlation and followed a consequent variation dependent on the carbon equivalent. Furthermore, the quality of the prediction was dependent on the used numerical algorithm involving cooling information from either one or two thermocouples.

  • 27.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Hernando, Juan Carlos
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Holmgren, Daniel
    Tenneco Inc., Sweden.
    Effect of inoculation on the material property in cast iron2022Conference paper (Refereed)
  • 28.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Swerea Swecast.
    Lora, Ruben
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Austenite Dendrite Morphology in Lamellar Cast Iron2014In: The 10th International Symposium on the Science and Processing of Cast Iron, SPCI10, November, Mar del Plata, Argentina, 2014, The Institute for Research in Materials Science and Technology (INTEMA) , 2014Conference paper (Refereed)
    Abstract [en]

    Primary austenite has been underestimated in general when the theories of nucleation, solidification, microstructure formation and mechanical properties was established for cast iron and particularly for lamellar cast iron. After extensive use of colour etching during the last two decades it has been found that primary austenite dendrites can be characterized using general morphology parameters like those used for other technical cast alloys with dendritic structure. The present work aims to investigate the primary austenite morphology of as-cast samples of a hypoeutectic lamellar cast iron produced with different cooling rates. Morphological parameters as the area fraction primary austenite, the secondary dendrite arm spacing, the dendrite envelope surface, the coarseness of the primary dendrite expressed as the relation between the volume of the dendrite and its envelope surface and the coarseness of the interdendritic space also known as the hydraulic diameter are measured. Furthermore the role of the size of investigation area is revealed be sequential investigation. A strong relation between all measured morphological parameters and the solidification time have been established excepting the volume fraction of primary austenite which is constant for all cooling conditions.

  • 29.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Swerea Swecast.
    Lora, Ruben
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Austenite dendrite morphology in lamellar graphite iron2015In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 28, no 5, p. 310-317Article in journal (Refereed)
    Abstract [en]

    Primary austenite has been underestimated in general when the theories of nucleation, solidification, microstructure formation and mechanical properties were established for cast iron and particularly for lamellar cast iron. The present work aims to investigate the primary austenite morphology of as cast samples of a hypoeutectic lamellar cast iron produced with different cooling rates. Morphological parameters as the area fraction primary austenite, the secondary dendrite arm spacing, the dendrite envelope surface, the coarseness of the primary dendrite expressed as the relation between the volume of the dendrite and its envelope surface and the coarseness of the interdendritic space also known as the hydraulic diameter are measured. Furthermore, the role of the size of the investigation area is revealed to be sequential investigation. A strong relation between all measured morphological parameters and the solidification time has been established, except the volume fraction of primary austenite, which is constant for all cooling conditions.

  • 30.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Fourlakidis, Vasilios
    Swerea - Swecast.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Fracture Mechanics of Gray Cast Iron2010In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 649, p. 517-522Article in journal (Refereed)
    Abstract [en]

    The fracture mechanism of gray cast iron was investigated on tension loaded samples produced under different conditions. The parameters studied included the graphite morphology, the carbon content, the inoculation and the cooling condition. The observations made reveal the role of the microstructure on crack propagation. The cracks were found to always propagate parallel with the graphite flakes. The interaction between the metallic matrix precipitated as primary austenite and graphite has been interpreted by a simplified model of the austenite reinforced eutectic cell. The geometrical transcription gave a standard crack component configuration with known mathematical solution. The microstructure observed in the experiments has been analysed by means of a novel interpretation. The fictitious stress intensity at yield and the fictitious maximum stress intensity at failure are strongly related to the relative shape of the eutectic cell and the fraction primary austenite. A different slope is observed for the material cooled at high rate when the precipitation of primary carbide reduces the stress intensity. The observed relations indicate that the tensile strength of the grey cast iron is the result of the collaboration between the toughness of the metallic matrix precipitated as primary austenite and the brittleness of the graphite phase. The shape and distribution of the primary austenite and graphite can be influenced by chemical composition, by inoculation or by the cooling condition, but they will maintain equilibrium with respect to the stress intensity.

  • 31.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Mechanical Engineering. Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Fourlakidis, Vasilios
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH, Mechanical Engineering. Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Microstructure and tensile properties of grey cast iron2004Report (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 32.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Hattel, Jesper
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Inverse thermal analysis method to study solidification in cast iron2004In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 17, no 5, p. 311-318Article in journal (Refereed)
  • 33.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Liu, Kalle Z
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Inoculation of Primary Austenite in Grey Cast Iron2006Conference paper (Refereed)
  • 34.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Liu, Kalle Z
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Inoculation of Primary Austenite in Grey Cast Iron2007In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 20, no 2, p. 68-72Article in journal (Refereed)
  • 35.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Lora, Ruben
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Fourlakidis, Vasilios
    Swerea Swecast.
    Dynamic Coarsening of Austenite Dendrite in Lamellar Cast Iron Part 1 – Investigation based on interrupted solidification2014In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 790-791, p. 205-210Article in journal (Refereed)
    Abstract [en]

    Dynamic coarsening of austenite dendrite in lamellar cast iron has been studied for a hypoeutectic alloy. The common morphological parameter to characterize dynamic coarsening, secondary dendrite arm space has been replaced by the Modulus of primary dendrite (MPD) and the Hydraulic diameter of the interdendritic space (DHydIP) to interpret the dynamic coarsening with respect to the local solidification time. The obtained results demonstrate the coarsening process of both the solid and liquid phase. The interdendritic space is increasing as the contact time between the solid and liquid phase increases. The ratio between the DHydIP/MPD is strongly dependent on the precipitated fraction primary austenite indicating clearly the morphology variation during coarsening. The interrupted solidification method demonstrate that the observed coarsening process is not only a combination of the increasing fraction precipitated solid phase and the rearrangement of the solid - liquid interphase curvature but the volume change due to density variation is also contribute to the coarsening process.

  • 36.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Millberg, Adam
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Microstructure evaluation and simulation of mechanical properties of a cylinder head in cast iron2001In: The science of Casting and Solidification, Brassó-Brasov, Romania, 2001, p. 269-277Conference paper (Refereed)
  • 37.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Interpretation of Solidification by Thermal Analysis of Cooling Rate2005In: Transactions of the Indian Institute of Metals, ISSN 0019-493X, Vol. 58, no 4, p. 611-616Article in journal (Refereed)
  • 38.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Inverse kinetic analysis method to study eutectic growth2005In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 18, no 1, p. 41-45Article in journal (Refereed)
  • 39.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Lemezgrafitos öntöttvas dermedési mecanizmusai2007Conference paper (Other academic)
  • 40.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting.
    Lemezgrafitos öntöttvas szakító szilárdságának számítógépes modellezése2005Conference paper (Other academic)
  • 41.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Svensson, Ingvar L
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    On the problems of thermal analysis of solidification2005In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 413-414, p. 474-479Article in journal (Refereed)
  • 42.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svidró, Peter
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Elmquist, Lennart
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. SinterCast AB.
    Dugic, Izudin
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Linnaeus University.
    Defect formation mechanisms in lamellar cast iron related to the casting geometry2015In: Advances in the Science and Engineering of Casting Solidification: An MPMD Symposium Honoring Doru Michael Stefanescu / [ed] L. Nastac, B. Liu, H. Fredriksson, J. Lacaze, C.-P. Hong, A. V. Catalina, A. Buhrig-Polaczek, C. Monroe, A. S. Sabau, R. E. L. Ruxanda, A. Luo, S. Sen and A. Diószegi, John Wiley & Sons, 2015, p. 251-259Chapter in book (Refereed)
  • 43.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svidró, Peter
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Elmquist, Lennart
    SinterCast AB, Technical Centre, Katrineholm, Sweden.
    Dugic, Izudin
    Faculty of Technology, Department of Mechanical Engineering, Linnaeus University, Växjö, Sweden.
    Defect formation mechanisms in lamellar graphite iron related to the casting geometry2016In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 29, no 5, p. 279-285Article in journal (Refereed)
    Abstract [en]

    Although lamellar cast iron has been used in advanced applications for about 20 years, our knowledge about the mechanisms affecting microstructure and defect formation is relatively limited. The present paper summarises some solidification-related phenomena from a series of recently published peer-reviewed papers and scientific theses and suggests a mechanism of defect formation which is dependent on the shape of the solidifying casting geometry. When shrinkage porosity or metal expansion penetration occurs, evidence of material transport in the intergranular zone of primary equiaxed austenite grains in the casting and in the intergranular regions between the sand grains in the mould material is seen. Material transport occurs across the casting-mould interface, where the existence of or the permeability of the primary columnar zone determines if material transport can take place.

  • 44.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Svidró, Péter
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Method of and device for analysing a phase transformation of a material2018Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    A method of analyzing a phase transformation process of a material comprises providing a spherical sample of the material, measuring and recording a first data series of core temperature at the sample's center of gravity, measuring and recording a respective second data series of temperature at the sample's periphery, measuring and recording a respective third data series of radial displacements at the sample's periphery, and calculating a change in pressure in the sample at a plurality of points in time based on first, second and third said data series.

  • 45.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Svidró, Péter
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Volumetric changes during the Solidification of Cast Iron2017In: ASM Handbook, Volume 1A: Cast Iron Science and Technology / [ed] Doru M. Stefanescu, Materials Park, Ohio: ASM International, 2017, p. 88-93Chapter in book (Refereed)
  • 46.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Wessén, Magnus
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Measurement and simulation of thermal condition and mechanical properties in a complicated shaped cylinder head cast in grey iron2000Conference paper (Refereed)
  • 47.
    Diószegi, Attila
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Wessén, Magnus
    Jönköping University, School of Engineering, JTH. Research area Materials and Manufacturing - Casting. Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Measurement and simulation of thermal condition and mechanical properties in a complicated shaped cylinder head cast in grey iron2001In: Indian Foundry Journal, Vol. 8, no 4Article in journal (Other academic)
  • 48.
    Domeij, Björn
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Belov, Ilja
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Implementation and Validation of Casting Simulation Methodology for Diagnostics of Lamellar Graphite Iron2023In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 17, p. 1507-1517Article in journal (Refereed)
    Abstract [en]

    This paper describes and validates a methodology for implementation of full-scale sand-casting simulation in a general-purpose finite element software, including mold filling, heat transport, solidification kinetics, chemical microsegregation and prediction of microstructure and material properties. The solidification model, customized for gray cast iron, includes novel methods for handling interaction between parallel dendritic and eutectic solidification modes and its impact of their interaction on the final microstructure. The validation involves a previously published gray iron casting experiment and involves comparison of simulated and experimental cooling curves, microstructure parameters and tensile strength. We believe that this is valuable to researchers and engineers seeking to improve the state of the art of casting simulation tools.

  • 49.
    Domeij, Björn
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Belov, Ilja
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Fourlakidis, Vasilios
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Metodik för kort väg mellan forskning och gjutsimuleringsverktyg2023In: Gjuteriet, E-ISSN 0017-0682, no 1, p. 12-13Article in journal (Other (popular science, discussion, etc.))
  • 50.
    Domeij, Björn
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    A review of dendritic austenite in cast irons2024In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193Article, review/survey (Refereed)
    Abstract [en]

    Solidification of cast irons usually involves dendritic growth of austenite. This article presents a literature survey about the dendrites in cast irons, their consequences and how they may be manipulated. The literature review is supplemented with relevant micrographs from our research. While austenite usually transforms into ferrite or pearlite, the dendrites limit where liquid flows, where eutectic grows, and where segregated elements go. The amount and shape of dendrites show correlations with tensile strength in pearlitic gray and compacted graphite irons. There are also indications that a coarse dendrite grain structure may be beneficial to tensile strength. The dendrite grain structure depends on melting process parameters and shows sensitivity to melt treatment. The evolution of scale of dendrite arms and their spacing under isothermal condition is by now fairly well-understood; however, work remains to better understand its evolution during cooling and its interaction with the eutectic. The amount and shape of dendrites are less understood in irons of near-eutectic and hypereutectic composition, in particular mixtures of dendrites of distinct scales, associated with regions of distinct graphite morphology. While significant advances have been made in recent years, the role and control of dendrites remain a relatively unexplored area of research with potential to improve production and properties of cast irons.

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