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Zhu, B., Seifeddine, S., Jarfors, A. E. .., Leisner, P. & Zanella, C. (2019). A study of anodising behaviour of Al-Si components produced by rheocasting. Paper presented at 15th International conference on semi-solid processing of alloys and composites, October 22nd to 24th, 2018, Shenzhen, China. Solid State Phenomena, 285, 39-44
Open this publication in new window or tab >>A study of anodising behaviour of Al-Si components produced by rheocasting
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2019 (English)In: Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779, Vol. 285, p. 39-44Article in journal (Refereed) Published
Abstract [en]

This paper aims to investigate the anodising behaviour of Al-Si components produced by rheocasting, to understand the effect of the surface liquid segregation (SLS) on the anodising response. The material investigated was EN AC 42000 Al-alloy with an addition of 150 ppm Sr. The component was rheocast and conventionally liquid cast for benchmarking. The RheoMetalTM process was used to prepare slurry and subsequently cast using a vertical pressure die casting machine. Prior to anodising, mechanical grinding was used as pre-treatment method for selected samples as comparison with components in the as-cast state. Anodising was performed on the components using a constant controlled voltage at 25 V, in 1 M H2SO4, at room temperature. The duration of anodising was varied from 30 mins to 120 mins to examine the relationship between oxide layer thickness and the anodising time. The oxide layer was investigated and characterised. The results demonstrated that the presence of the SLS layer, which was enriched with alloying elements, had a significant influence on the anodising behaviour of the cast component. The oxide layer thickness of the components produced by rheocasting and fully liquid casting was measured and compared. The relations between the oxide layer thickness and anodising time, as well as the casting methods are presented and discussed in this paper.

Place, publisher, year, edition, pages
Trans Tech Publications, 2019
Keywords
Anodising, Oxide Layer, Rheocasting
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-42630 (URN)10.4028/www.scientific.net/SSP.285.39 (DOI)2-s2.0-85059944290 (Scopus ID)
Conference
15th International conference on semi-solid processing of alloys and composites, October 22nd to 24th, 2018, Shenzhen, China
Available from: 2019-01-14 Created: 2019-01-14 Last updated: 2019-05-09Bibliographically approved
Tarasov, V., Tan, H., Jarfors, A. E. .. & Seifeddine, S. (2019). Fuzzy logic-based modelling of yield strength of as-cast A356 alloy. Neural computing & applications (Print)
Open this publication in new window or tab >>Fuzzy logic-based modelling of yield strength of as-cast A356 alloy
2019 (English)In: Neural computing & applications (Print), ISSN 0941-0643, E-ISSN 1433-3058Article in journal (Refereed) Epub ahead of print
Abstract [en]

Uncertain and imprecise data are inherent to many domains, e.g. casting lightweight components. Fuzzy logic offers a way to handle such data, which makes it possible to create predictive models even with small and imprecise data sets. Modelling of cast components under fatigue load leads to understanding of material behaviour on component level. Such understanding is important for the design for minimum warranty risk and maximum weight reduction of lightweight cast components. This paper contributes with a fuzzy logic-based approach to model fatigue-related mechanical properties of as-cast components, which has not been fully addressed by the current research. Two fuzzy logic models are constructed to map yield strength to the chemical composition and the rate of solidification of castings for two A356 alloys. Artificial neural networks are created for the same data sets and then compared to the fuzzy logic approach. The comparison shows that although the neural networks yield similar prediction accuracy, they are less suitable for the domain because they are opaque models. The prediction errors exhibited by the fuzzy logic models are 3.53% for the model and 3.19% for the second, which is the same error level as reported in related work. An examination of prediction errors indicated that these are affected by parameters of the membership functions of the fuzzy logic model.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Fuzzy logic; Membership functions; Artificial neural networks; Prediction accuracy; Mechanical properties prediction; A356 alloy; Cast components
National Category
Materials Engineering Computer Engineering
Identifiers
urn:nbn:se:hj:diva-42912 (URN)10.1007/s00521-019-04056-5 (DOI)XYZ ()
Funder
Knowledge Foundation, 20170066
Available from: 2019-02-08 Created: 2019-02-08 Last updated: 2019-08-21
Borkar, H., Seifeddine, S. & Jarfors, A. E. .. (2019). Microstructure, texture and mechanical properties of al alloy a380 prepared by directional solidification method. In: Manufacturing Sciences and Technologies IX: 9th International Conference on Manufacturing Science and Technology (ICMST 2018). Paper presented at 9th International Conference on Manufacturing Science and Technology, ICMST 2018, Kuala Lumpur, Malaysia, 11 - 13 August 2018 (pp. 18-23). Trans Tech Publications, 287
Open this publication in new window or tab >>Microstructure, texture and mechanical properties of al alloy a380 prepared by directional solidification method
2019 (English)In: Manufacturing Sciences and Technologies IX: 9th International Conference on Manufacturing Science and Technology (ICMST 2018), Trans Tech Publications, 2019, Vol. 287, p. 18-23Conference paper, Published paper (Refereed)
Abstract [en]

The mechanical properties of Al-Si alloys are affected by several microstructural features such as secondary dendrite arm spacing (SDAS), size and shape of eutectic Si-particles, presence of intermetallics as well as by porosity. In the current study, Al-Si-Cu alloy A380 was prepared by a unique directional solidification method to produce samples with two different SDAS of 9 μm and 27 μm. The lower solidification rate resulted in larger SDAS, larger grain size, larger eutectic Si and larger intermetallics including Fe-rich β phase. The microstructure with higher solidification rate was found to be finer and more homogeneous with smaller eutectic Si and intermetallics. The specimen with larger SDAS exhibited stronger texture than the one with smaller SDAS. The specimen with smaller SDAS showed improved mechanical properties including YS, UTS and ductility. 

Place, publisher, year, edition, pages
Trans Tech Publications, 2019
Series
Diffusion and defect data, solid state data. P. B, Solid state phenomena, ISSN 1012-0394, E-ISSN 1662-9779 ; 287
Keywords
Al-Si-Cu alloys, Electron backscattered diffraction, Secondary dendrite arm spacing, Solidification, Aluminum alloys, Copper alloys, Dendrites (metallography), Eutectics, Intermetallics, Manufacture, Mechanical properties, Textures, Electron back-scattered diffraction, Eutectic si, Microstructural features, Properties of Al, Si-Cu alloys, Size and shape, Solidification rate, Silicon alloys
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-43602 (URN)10.4028/www.scientific.net/SSP.287.18 (DOI)2-s2.0-85064218056 (Scopus ID)9783035713886 (ISBN)9783035733884 (ISBN)
Conference
9th International Conference on Manufacturing Science and Technology, ICMST 2018, Kuala Lumpur, Malaysia, 11 - 13 August 2018
Available from: 2019-05-07 Created: 2019-05-07 Last updated: 2019-05-07Bibliographically approved
Olofsson, J., Bjurenstedt, A. & Seifeddine, S. (2019). On the effects of defects and imperfections on tensile toughness of a secondary aluminium alloy. In: Murat Tiryakioḡlu, William Griffiths, Mark Jolly (Ed.), Shape casting: 7th International Symposium Celebrating Prof. John Campbell's 80th Birthday. Paper presented at Shape casting : 7th International Symposium Celebrating Prof. John Campbell's 80th Birthday (pp. 131-141). Springer
Open this publication in new window or tab >>On the effects of defects and imperfections on tensile toughness of a secondary aluminium alloy
2019 (English)In: Shape casting: 7th International Symposium Celebrating Prof. John Campbell's 80th Birthday / [ed] Murat Tiryakioḡlu, William Griffiths, Mark Jolly, Springer, 2019, p. 131-141Conference paper, Published paper (Refereed)
Abstract [en]

In order to design and produce high-quality castings with reliable performance, the effect of the melt handling and melt quality during different processing stages needs to be understood and controlled, and numerical methods to provide correct input data to structural analyses of castings enabled. This paper aims to investigate tensile properties, in particular tensile toughness, of a secondary high-pressure die casting (HPDC) aluminium alloy with different levels of defects and imperfections. The melt, which was transported in liquid state from the smelter to the foundry, has been sampled after different holding times by casting into Y-blocks. Tensile testing was performed, and the levels of defects and imperfections were characterized using measurements of porosity, bifilm index, density index, sludge factor and the amount of iron-rich intermetallics. Two different quality indices have been evaluated, and a method to apply the results in simulations of damage in a casting, containing defects, subjected to load is demonstrated. 

Place, publisher, year, edition, pages
Springer, 2019
Series
Minerals, Metals and Materials Series, ISSN 2367-1181, E-ISSN 2367-1696
Keywords
Component casting, Defects, Quality index, Shape casting, Toughness, Die casting, Numerical methods, Tensile testing, High pressure die casting, High quality castings, Measurements of, Processing stage, Quality indices, Reliable performance, Tensile toughness, Quality control
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-43568 (URN)10.1007/978-3-030-06034-3_13 (DOI)2-s2.0-85064063515 (Scopus ID)9783030060336 (ISBN)9783030060343 (ISBN)
Conference
Shape casting : 7th International Symposium Celebrating Prof. John Campbell's 80th Birthday
Available from: 2019-05-02 Created: 2019-05-02 Last updated: 2019-05-02Bibliographically approved
Zamani, M., Toschi, S., Morri, A., Ceschini, L. & Seifeddine, S. (2019). Optimisation of heat treatment of Al–Cu–(Mg–Ag) cast alloys. Journal of thermal analysis and calorimetry (Print)
Open this publication in new window or tab >>Optimisation of heat treatment of Al–Cu–(Mg–Ag) cast alloys
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2019 (English)In: Journal of thermal analysis and calorimetry (Print), ISSN 1388-6150, E-ISSN 1588-2926Article in journal (Refereed) Epub ahead of print
Abstract [en]

The optimisation of heat treatment parameters for Al–Cu–(Mg–Ag) cast alloys (2xxx) having different microstructural scales was investigated. Thermo-Calc software was used to design optimal alloy compositions. Differential scanning calorimetry (DSC), scanning electron microscopy and wavelength-dispersive spectroscopy technique were employed to determine proper solution heat treatment temperature and homogenisation time as well as incidence of incipient melting. Proper artificial ageing temperature for each alloy was identified using DSC analysis and hardness measurement. Microstructural scale had a pronounced influence on time and temperature required for complete dissolution of Al2Cu and homogenisation of Cu solute atoms in the α-Al matrix. Refined microstructure required only one-step solution treatment and relatively short solution treatment of 10 h to achieve dissolution and homogenisation, while coarser microstructures desired longer time. Addition of Mg to Al–Cu alloys promoted the formation of phases having a rather low melting temperature which demands multi-step solution treatment. Presence of Ag decreases the melting temperature of intermetallics (beside Al2Cu) and improvement in age-hardening response. Peak-aged temperature is primarily affected by the chemical composition rather than the microstructural scale. 

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Artificial ageing, Cast Al–Cu alloys, Coarseness of microstructure, DSC, Solidification rate, Solution treatment, Thermal treatment, Age hardening, Aluminum alloys, Binary alloys, Copper alloys, Differential scanning calorimetry, Dissolution, Melting point, Microstructure, Scanning electron microscopy, Silver alloys, Wavelength dispersive spectroscopy, Chemical compositions, Cu alloy, Heat treatment parameters, Low melting temperatures, Refined microstructure, Solution treatments, Heat treatment
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-46240 (URN)10.1007/s10973-019-08702-x (DOI)2-s2.0-85072042594 (Scopus ID);JTHMaterialIS (Local ID);JTHMaterialIS (Archive number);JTHMaterialIS (OAI)
Available from: 2019-09-18 Created: 2019-09-18 Last updated: 2019-09-18
Bogdanoff, T., Ghassemali, E., Riestra, M. & Seifeddine, S. (2019). Prototyping of a high pressure die cast al-si alloy using plaster mold casting to replicate corresponding mechanical properties. In: Minerals, Metals and Materials Series: . Paper presented at Light Metals Symposium held at the TMS Annual Meeting and Exhibition, 2019, San Antonio, United States, 10 - 14 March 2019 (pp. 435-442). Springer
Open this publication in new window or tab >>Prototyping of a high pressure die cast al-si alloy using plaster mold casting to replicate corresponding mechanical properties
2019 (English)In: Minerals, Metals and Materials Series, Springer, 2019, p. 435-442Conference paper, Published paper (Refereed)
Abstract [en]

Prototyping prior high pressure die casting (HPDC) is used for product/mold design optimization. Plaster mold casting is a cost-efficient prototyping technique providing good surface quality and dimension accuracy, similar to HPDC components. However, the corresponding mechanical properties of a component produced with these two methods are diverging significantly, mainly due to differences in the cooling rate. This work presents a procedure to optimize the plaster mold casting for prototyping to replicate mechanical properties of a commonly used Al-Si alloy (A380). Two commercial alloys with compositions close to the A380 alloy (A356.0 and A360.2) were used. Yield strength was considered as the main design criteria, thus the target mechanical property. Tensile testing results showed that with an optimized T6 heat treatment, not only the yield strength, but also ultimate tensile strength and elongation correspond well to the properties in the HPDC component.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Aluminium alloys, Heat treatment, Prototyping, Aluminum alloys, Die casting, Light metals, Mechanical properties, Molds, Plaster, Product design, Software prototyping, Tensile strength, Tensile testing, Yield stress, Commercial alloys, Design criteria, Design optimization, Dimension accuracy, High pressure die casting, High pressure die casts, T6 heat treatment, Ultimate tensile strength, Silicon alloys
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-43728 (URN)10.1007/978-3-030-05864-7_56 (DOI)2-s2.0-85064856753 (Scopus ID)9783030058630 (ISBN)9783030058647 (ISBN)
Conference
Light Metals Symposium held at the TMS Annual Meeting and Exhibition, 2019, San Antonio, United States, 10 - 14 March 2019
Available from: 2019-05-22 Created: 2019-05-22 Last updated: 2019-05-22Bibliographically approved
Bjurenstedt, A., Ghassemali, E., Seifeddine, S. & Dahle, A. (2019). The effect of Fe-rich intermetallics on crack initiation in cast aluminium: an in-situ tensile study. Materials Science & Engineering: A, 756, 502-507
Open this publication in new window or tab >>The effect of Fe-rich intermetallics on crack initiation in cast aluminium: an in-situ tensile study
2019 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 756, p. 502-507Article in journal (Refereed) Published
Abstract [en]

To evaluate the role of Fe-rich intermetallics on crack initiation, two fully modified Al-Si alloys, one containing plate-like β-Fe and the second containing primary α-Fe intermetallics, were investigated by in-situ tensile testing in the scanning electron microscope. In the first alloy, large plate-like β-Fe intermetallics oriented parallel to the test direction were the first to crack at an elongation of about 1.8%. More transversely oriented intermetallics caused crack initiation in the matrix which linked up with the final fracture. In the second alloy, the cracking of α-Fe intermetallics initiated at an elongation of about 0.9%. It is concluded that large α-Fe intermetallics crack first and that clusters of α-Fe are the most potent crack initiation sites.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Al-Si alloy, Cast aluminium, Fracture mechanics, Tensile testing in SEM, α-Fe, β-Fe, Aluminum alloys, Crack initiation, Cracks, Fracture testing, Intermetallics, Materials testing apparatus, Metal testing, Scanning electron microscopy, Silicon alloys, Tensile testing
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-36962 (URN)10.1016/j.msea.2018.07.044 (DOI)000469893400058 ()2-s2.0-85064717473 (Scopus ID)
Available from: 2017-08-21 Created: 2017-08-21 Last updated: 2019-06-20Bibliographically approved
Bogdanoff, T., Dahle, A. K. & Seifeddine, S. (2018). Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy. International Journal of metalcasting, 12(3), 434-440
Open this publication in new window or tab >>Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy
2018 (English)In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 12, no 3, p. 434-440Article in journal (Refereed) Published
Abstract [en]

Increasing environmental demands are forcing the automotive industry to reduce vehicle emissions by producing more light-weight and fuel efficient vehicles. Al–Si alloys are commonly used in automotive applications because of excellent castability, high thermal conductivity, good wear properties and high strength-to-weight ratio. However, most of the aluminium alloys on the market exhibit significantly reduced strength at temperatures above 200 °C. This paper presents results of a study of the effects of Co and Ni in a hypoeutectic Al–Si alloy on microstructure and mechanical properties at room and elevated temperature. Tensile test specimens with microstructures comparable to those obtained in high-pressure die casting, i.e. SDAS ~ 10 µm, were produced by directional solidification in a Bridgman furnace. The results show an improvement in tensile properties up to 230 °C.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
Al–Si alloy, mechanical properties, cobalt, nickel, elevated temperature
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-37539 (URN)10.1007/s40962-017-0178-z (DOI)000436927100004 ()2-s2.0-85049356111 (Scopus ID)
Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2019-02-05Bibliographically approved
Ceschini, L., Morri, A., Toschi, S., Bjurenstedt, A. & Seifeddine, S. (2018). Influence of sludge particles on the fatigue behavior of Al-Si-Cu secondary aluminium casting alloys. Metals, 8(4), Article ID 268.
Open this publication in new window or tab >>Influence of sludge particles on the fatigue behavior of Al-Si-Cu secondary aluminium casting alloys
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2018 (English)In: Metals, E-ISSN 2075-4701, Vol. 8, no 4, article id 268Article in journal (Refereed) Published
Abstract [en]

Al-Si-Cu alloys are the most widely used materials for high-pressure die casting processes. In such alloys, Fe content is generally high to avoid die soldering issues, but it is considered an impurity since it generates acicular intermetallics (β-Fe) which are detrimental to the mechanical behavior of the alloys. Mn and Cr may act as modifiers, leading to the formation of other Fe-bearing particles which are characterized by less harmful morphologies, and which tend to settle on the bottom of furnaces and crucibles (usually referred to as sludge). This work is aimed at evaluating the influence of sludge intermetallics on the fatigue behavior of A380 Al-Si-Cu alloy. Four alloys were produced by adding different Fe, Mn and Cr contents to A380 alloy; samples were remelted by directional solidification equipment to obtain a fixed secondary dendrite arm spacing (SDAS) value (~10 µm), then subjected to hot isostatic pressing (HIP). Rotating bending fatigue tests showed that, at room temperature, sludge particles play a detrimental role on fatigue behavior of T6 alloys, diminishing fatigue strength. At elevated temperatures (200◦C) and after overaging, the influence of sludge is less relevant, probably due to a softening of the α-Al matrix and a reduction of stress concentration related to Fe-bearing intermetallics.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
Al-Si-Cu alloys, Fatigue behavior, High pressure die casting, Intermetallics, Iron, Sludge
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-39389 (URN)10.3390/met8040268 (DOI)000434882800071 ()2-s2.0-85045762852 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-05-15 Created: 2018-05-15 Last updated: 2019-02-14Bibliographically approved
Wójcik, N. A., Jonson, B., Möncke, D., Palles, D., Kamitsos, E. I., Ghassemali, E., . . . Ali, S. (2018). Influence of synthesis conditions on glass formation, structure and thermal properties in the Na2O-CaO-P2O5 system doped with Si3N4 and Mg. Journal of Non-Crystalline Solids, 494, 66-77
Open this publication in new window or tab >>Influence of synthesis conditions on glass formation, structure and thermal properties in the Na2O-CaO-P2O5 system doped with Si3N4 and Mg
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2018 (English)In: Journal of Non-Crystalline Solids, ISSN 0022-3093, E-ISSN 1873-4812, Vol. 494, p. 66-77Article in journal (Refereed) Published
Abstract [en]

Oxynitride phosphate glasses and glass-ceramics were prepared using new synthesis routes for phosphate glasses. Materials were melted from pre-prepared glass samples in the system Na-Ca-P-O with addition of Mg and/or Si3N4 powders under different preparation conditions. The melting process was conducted at 1000–1500 °C either under air or nitrogen atmosphere to obtain materials with different nitrogen content. Their topography and structure were characterized by Confocal Microscopy, Scanning Electron Microscopy, X-ray powder diffraction and Raman and infrared spectroscopy techniques, while their chemical compositions were examined by Energy Dispersive X-ray spectroscopy (EDS). All materials prepared under nitrogen atmosphere were found to contain a relative low quantity of nitrogen and high amount of Nb leached from the crucible. The reaction with the Nb crucible was not previously observed for silicon-based oxynitride glasses. The synthesized materials form two groups: glasses and glass-ceramics. The first ones, were prepared under air and nitrogen atmospheres at temperatures up to 1400 °C, and were found to be amorphous and homogeneous. Raman and infrared spectroscopy measurements confirm the presence of amorphous phosphates in the synthesized materials. The samples of the second group were prepared at temperatures above 1400 °C and were found to be translucent and partially crystallized. They contain nanocrystallites of calcium and sodium phosphates including hydroxyapatite (HAp). The thermal properties of samples were studied by Differential Scanning Calorimetry (DSC). The obtained glass transition temperatures range from about 360 °C to 640 °C and exhibit high values for glass-ceramic materials. Stability is improved in the studied glass-ceramics because of the increased degree of network polymerization of the remaining glassy matrix. The approximate fragility index decreases two times for oxynitride materials compared to the primary glass. The synthesized new materials may be competitive to well-known bioactive phosphate glasses thanks to their improved stability by Mg, Si, N and Nb doping.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Sodium-calcium-phosphate glasses, Glass-ceramics, Oxynitride materials, Raman spectroscopy
National Category
Ceramics
Identifiers
urn:nbn:se:hj:diva-39381 (URN)10.1016/j.jnoncrysol.2018.04.055 (DOI)000436885100009 ()2-s2.0-85046826853 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-05-09 Created: 2018-05-09 Last updated: 2019-02-14Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-6481-5530

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