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Jarfors, Anders E.W.ORCID iD iconorcid.org/0000-0002-0101-0062
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Publications (10 of 156) Show all publications
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: 2019-01-31Bibliographically 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: 2019-02-08
Ghasemi, R., Johansson, J., Ståhl, J.-E. & Jarfors, A. E. .. (2019). Load effect on scratch micro-mechanisms of solution strengthened Compacted Graphite Irons. Tribology International, 133, 182-192
Open this publication in new window or tab >>Load effect on scratch micro-mechanisms of solution strengthened Compacted Graphite Irons
2019 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 133, p. 182-192Article in journal (Refereed) Published
Abstract [en]

This study investigates the scratch load effect, from 100 to 2000 mN, on micro-mechanisms involved during scratching. A pearlitic and three ferritic Compacted Graphite Irons (CGI) solution strengthened through addition of 3.66, 4.09, and 4.59 Si wt% were investigated. Good correlation was observed between hardness measurements, tensile testing, and scratch results explaining the influence of matrix characteristics on scratch behaviour for investigated alloys. A significant matrix deformation, change in frictional force and scratch coefficient of friction was observed by increase in scratch load. In all cases, microscratch depth and width increased significantly with load increasing, however pearlitic CGI showed most profound deformation, while the maximum and minimum scratch resistances were observed for high-Si ferritic and pearlitic CGI alloys, respectively.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
CGI, Si solution-strengthening, Scratch testing, Deformation micro-mechanisms during scratching
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-42653 (URN)10.1016/j.triboint.2019.01.010 (DOI)000458943500018 ()2-s2.0-85059818887 (Scopus ID)PP JTH 2019 embargo 24 (Local ID)PP JTH 2019 embargo 24 (Archive number)PP JTH 2019 embargo 24 (OAI)
Available from: 2019-01-16 Created: 2019-01-16 Last updated: 2019-03-13Bibliographically approved
Jarfors, A. E. .., Zheng, J., Chen, L. & Yang, J. (2019). Recent advances in commercial application of the rheometal process in China and Europe. In: Rassili A.,Midson S.P.,Zhu Q.,Gang Hu X. (Ed.), Semi-Solid of Alloys and Composites: . Paper presented at 15th International conference on Semi-Solid Processing of Alloys and Composites, S2P 2018; Shenzhen; China; 22 - 24 October 2018 (pp. 405-410). Trans Tech Publications
Open this publication in new window or tab >>Recent advances in commercial application of the rheometal process in China and Europe
2019 (English)In: Semi-Solid of Alloys and Composites / [ed] Rassili A.,Midson S.P.,Zhu Q.,Gang Hu X., Trans Tech Publications, 2019, p. 405-410Conference paper, Published paper (Refereed)
Abstract [en]

Recent advances in rheocasting have resulted in significant expansion in the types of products currently in full commercial production. The current paper gives an overview of components in production in Europe and in China produced using the RheoMetal™ process, that has taken the lead in a strong drive towards new heavy-duty applications made from aluminium alloys. In China, the dominating applications are found in the telecom industry. The trend in Europe is more towards marine and automotive applications commonly in fatigue loaded applications. The reason for the choice of rheocasting for complicated shape thin-walled electronics components with requirements is dominated by process yield and by the ability to improve thermal conductivity. The heavy-duty truck chassis thick walled components target weight reduction through design and to sustain fatigue load normally requiring forged components. Common in all applications are seen in production yield, reduced tool wear and reduction of die soldering.

Place, publisher, year, edition, pages
Trans Tech Publications, 2019
Series
Science, University and Society, ISSN 1653-6010
Series
Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779 ; 285
Keywords
Aluminium, Automotive, Commercialisation, Electronics, Hardness, Heat treatment, Marine, Production, Properties, RheoMetal™, Semisolid casting, Electronic equipment, Marine applications, Rheocasting, Soldering, Thin walled structures, Fatigue of materials
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-42797 (URN)10.4028/www.scientific.net/SSP.285.405 (DOI)2-s2.0-85059960754 (Scopus ID)9783035713732 (ISBN)9783035733730 (ISBN)
Conference
15th International conference on Semi-Solid Processing of Alloys and Composites, S2P 2018; Shenzhen; China; 22 - 24 October 2018
Available from: 2019-01-31 Created: 2019-01-31 Last updated: 2019-01-31Bibliographically approved
Ghassemali, E., Hernando, J. C., Stefanescu, D. M., Diószegi, A., Jarfors, A. E. .., Dluhoš, J. & Petrenec, M. (2019). Revisiting the graphite nodule in ductile iron. Scripta Materialia, 161, 66-69
Open this publication in new window or tab >>Revisiting the graphite nodule in ductile iron
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2019 (English)In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 161, p. 66-69Article in journal (Refereed) Published
Abstract [en]

The growth mechanism of graphite nodules in ductile iron was experimentally investigated using high-resolution 3D tomography of an individual graphite nodule in a near-eutectic ductile iron. The dual beam scanning electron microscopy (FIB-SEM) technique was used for this purpose. Iron particles elongated in the radial direction were observed inside a graphite nodule. Some micro-voids were detected inside the nodule, mostly located at the end of the iron particles. These observations were compared with established theories about the growth of graphite nodules and iron entrapment/engulfment in between the graphite sectors during solidification of ductile iron. 

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
3D reconstruction, FIB, Growth mechanism, Solidification, Ductility, Graphite, Iron, Scanning electron microscopy, 3-d tomographies, Graphite nodules, Growth mechanisms, High resolution, Iron Particles, Micro voids, Radial direction, Cast iron
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-41986 (URN)10.1016/j.scriptamat.2018.10.018 (DOI)000450375500015 ()2-s2.0-85055115924 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-11-07 Created: 2018-11-07 Last updated: 2018-12-10Bibliographically approved
Santos, J., Jarfors, A. E. .. & Dahle, A. (2019). Variation of properties in the cross-section of semi-solid al-7si-0.3mg castings. In: Rassili A.,Midson S.P.,Zhu Q.,Gang Hu X. (Ed.), Semi-Solid of Alloys and Composites: . Paper presented at 15th International conference on Semi-Solid Processing of Alloys and Composites, S2P 2018; Shenzhen; China; 22 - 24 October 2018 (pp. 81-86). Trans Tech Publications
Open this publication in new window or tab >>Variation of properties in the cross-section of semi-solid al-7si-0.3mg castings
2019 (English)In: Semi-Solid of Alloys and Composites / [ed] Rassili A.,Midson S.P.,Zhu Q.,Gang Hu X., Trans Tech Publications, 2019, p. 81-86Conference paper, Published paper (Refereed)
Abstract [en]

In semi-solid casting, a slurry consisting of primary α-Al crystals and liquid is injected into the die cavity. The solidification in the die-cavity occurs by the growth of the primary α-Al crystals formed during slurry preparation and in the shot sleeve, nucleation and growth of in-cavity solidified crystals and ends with the eutectic reaction. During solidification in the die cavity, the cooling rate near the die wall is higher in comparison to the centre of the casting, particularly for thick-walled castings. The solidification conditions for the slurry α-Al crystals that are closer to the die wall can be very different compared to the slurry α-Al crystals located at the casting centre. This can result in different solute concentration in the interior of the α-Al globules in different regions of the semi-solid casting cross-section and consequently, different response to heat treatament. The RheoMetal™ process was used to produce thick-walled semi-solid castings. Semi-solid castings in the as-cast and T6 conditions were investigated. Indentation tests for hardness measurements in the nano-range were performed in the interior of α-Al globules near the surface and at the casting cross-section centre. The hardness variation across the casting cross-section was evaluated by low-force Vickers hardness. The castings in the as-cast condition showed more uniform properties in the cross-section compared to the T6 condition. Additionally, the results suggest that microsegregation in the interior of α-Al globules is very low in castings in the as-cast and T6 conditions. 

Place, publisher, year, edition, pages
Trans Tech Publications, 2019
Series
Science, University and Society, ISSN 1653-6010
Series
Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779 ; 285
Keywords
Hardness, Heat treatment, Properties, Rheometal™, Semi-solid casting, Die casting machines, Dies, Vickers hardness, Eutectic reactions, Hardness measurement, Hardness variation, Nucleation and growth, Semi solid casting, Solidification condition, Solute concentrations, Solidification
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-42786 (URN)10.4028/www.scientific.net/SSP.285.81 (DOI)2-s2.0-85059953796 (Scopus ID)9783035713732 (ISBN)9783035733730 (ISBN)
Conference
15th International conference on Semi-Solid Processing of Alloys and Composites, S2P 2018; Shenzhen; China; 22 - 24 October 2018
Available from: 2019-01-31 Created: 2019-01-31 Last updated: 2019-01-31Bibliographically approved
Siafakas, D., Matsushita, T., Lauenstein, Å., Ekerot, S. & Jarfors, A. (2018). A particle population analysis in Ti- and Al-deoxidized Hadfield steels. International Journal of Cast Metals Research, 31(3), 125-134
Open this publication in new window or tab >>A particle population analysis in Ti- and Al-deoxidized Hadfield steels
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2018 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 31, no 3, p. 125-134Article in journal (Refereed) Published
Abstract [en]

A quantitative analysis of the amount, size and number of particles that precipitate in situ in titanium- and aluminium-treated Hadfield steel cast during pilot-scale experiments has been performed. SEM with EDS and automated particle analysis abilities was utilized for the analysis. Additionally, Thermo-Calc was used for thermodynamic calculations and Magma 5 for solidification and cooling simulations. Predicted particles sizes calculated with a model based on the Ostwald ripening mechanism were compared with the experimental data. The effect of solute availability, cooling rate and deoxidation practice on the particle population characteristics was determined. It was concluded that the amount, size and number of precipitating particles in Hadfield steel castings is possible to be controlled according to certain requirements by a careful selection of proper additives in proper amounts and also by the optimization of the casting process in aspects of deoxidation timing and control of the cooling rate of the castings.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
Hadfield steel, particles population, deoxidation, casting, titanium, aluminum, inclusion control, particle growth
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-37418 (URN)10.1080/13640461.2017.1379262 (DOI)000437344000001 ()2-s2.0-85019740665 (Scopus ID)
Available from: 2017-09-27 Created: 2017-09-27 Last updated: 2019-01-24Bibliographically approved
Ghasemi, R., Elmquist, L., Ghassemali, E., Salomonsson, K. & Jarfors, A. E. .. (2018). Abrasion resistance of lamellar graphite iron: Interaction between microstructure and abrasive particles. Tribology International, 120, 465-475
Open this publication in new window or tab >>Abrasion resistance of lamellar graphite iron: Interaction between microstructure and abrasive particles
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2018 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 120, p. 465-475Article in journal (Refereed) Published
Abstract [en]

This study focuses on abrasion resistance of Lamellar Graphite Iron (LGI) using microscratch test under constant and progressive load conditions. The interactions between a semi-spherical abrasive particle, cast iron matrix and graphite lamellas were physically simulated using a sphero-conical indenter. The produced scratches were analysed using LOM and SEM to scrutinise the effect of normal load on resulting scratch depth, width, frictional force, friction coefficient and deformation mechanism of matrix during scratching. Results showed a significant matrix deformation, and change both in frictional force and friction coefficient by increase of scratch load. Furthermore, it was shown how abrasive particles might produce deep scratches with severe matrix deformation which could result in graphite lamella's coverage and thereby deteriorate LGI's abrasion resistance.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Lamellar graphite cast iron; Abrasion resistance; Scratch test; Microstructure; Pearlite deformation
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-38473 (URN)10.1016/j.triboint.2017.12.046 (DOI)000428102900046 ()2-s2.0-85041480396 (Scopus ID)
Available from: 2018-01-12 Created: 2018-01-12 Last updated: 2019-02-15Bibliographically approved
Kasvayee, K. A., Ciavatta, M., Ghassemali, E., Svensson, I. L. & Jarfors, A. E. .. (2018). Effect of Boron and Cross-Section Thickness on Microstructure and Mechanical Properties of Ductile Iron. Materials Science Forum, 925, 249-256
Open this publication in new window or tab >>Effect of Boron and Cross-Section Thickness on Microstructure and Mechanical Properties of Ductile Iron
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2018 (English)In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 925, p. 249-256Article in journal (Refereed) Published
Abstract [en]

Eeffect of Boron addition on the microstructure and mechanical properties of ductile iron, GJS-500-7 grade was studied. Three cast batches with the Boron content of 10, 49 and 131ppm were cast in a casting geometry containing plates with thicknesses of 7, 15, 30, 50 and 75mm. Microstructure analysis, tensile test, and hardness test were performed on the samples which were machined from the casting plates. Addition of 49 ppm Boron decreased pearlite fraction by an average of 34±6% in all the cast plates. However, minor changes were observed in the pearlite fraction by increasing Boron from 49 to 131 ppm. Variation in the plate thickness did not affect the pearlite fraction. The 0.2% offset yield and ultimate tensile strength was decreased by an average of 11±1% and 18±2%, respectively. Addition of 49 ppm Boron decreased Brinell hardness by 16±1%, while 11±2% reduction was obtained by addition of 131ppm Boron.

Place, publisher, year, edition, pages
Trans Tech Publications, 2018
Keywords
Boron, Component Casting, Ductile Iron, Hardness, Mechanical Properties, Spherical Graphite Iron
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:hj:diva-41056 (URN)10.4028/www.scientific.net/MSF.925.249 (DOI)XYZ ()2-s2.0-85050012940 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-07-25 Created: 2018-07-25 Last updated: 2019-01-25Bibliographically approved
Dini, H., Andersson, N.-E. & Jarfors, A. E. .. (2018). Effect of process parameters on distortion and residual stress of high-pressure die-cast AZ91D components. International Journal of metalcasting, 12(3), 487-497
Open this publication in new window or tab >>Effect of process parameters on distortion and residual stress of high-pressure die-cast AZ91D components
2018 (English)In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 12, no 3, p. 487-497Article in journal (Refereed) Published
Abstract [en]

This paper presents a study of distortion and residual stress within a high-pressure die-cast AZ91D component, cast under different processing conditions. The influence of process parameters, i.e., die temperature, cooling time, intensification pressure and first-phase injection speeds, was examined. Distortions were measured using the in-house standard analog quality control fixture. Residual stress depth profiles were measured using a prism hole-drilling method. It was found that the most important process parameter affecting the distortion was intensification pressure and the second most important was temperature difference between the two die halves (fixed and moving side). Tensile residual stresses were found very near the surface. Increasing the intensification pressure resulted in an increased level of tensile residual stresses.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
magnesium alloy; high-pressure die cast; distortion; residual stress
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-38146 (URN)10.1007/s40962-017-0186-z (DOI)000436927100010 ()2-s2.0-85049327484 (Scopus ID)HOA JTH 2018 (Local ID)HOA JTH 2018 (Archive number)HOA JTH 2018 (OAI)
Available from: 2017-12-12 Created: 2017-12-12 Last updated: 2019-02-14Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-0101-0062

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