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Eliasson, Anders, Senior LecturerORCID iD iconorcid.org/0000-0003-0864-3679
Publications (10 of 25) Show all publications
Warmlander, S. K. T., Saage, R., Erkers, L., Fröjd, F., Wahlander, L., Johnsson, P., . . . Eliasson, A. (2018). Amulets rather than iron bars. Metallographic analysis indicates uneven material quality in Vendel Period iron rings from Aselby in Stora Tuna parish, Dalecarlia. Fornvännen, 113(1), 1-6
Open this publication in new window or tab >>Amulets rather than iron bars. Metallographic analysis indicates uneven material quality in Vendel Period iron rings from Aselby in Stora Tuna parish, Dalecarlia
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2018 (English)In: Fornvännen, ISSN 0015-7813, E-ISSN 1404-9430, Vol. 113, no 1, p. 1-6Article in journal (Refereed) Published
Abstract [en]

29 iron rings with diameters between 9 and 15 cm were excavated in 1989 at a Vendel Period settlement site with a longhouse, located at Aselby in Dalecarlia, Sweden. Most of the rings had between one and three smaller rings attached. Rings of this type and size are fairly common at Scandinavian Vendel and Viking Period sites - settlements, cemeteries and cult precincts - but their function remains debated. The rings from Aselby have been interpreted as iron/steel bars, to be used or traded as raw material for e.g. weapons production. Previous metallurgical analysis of one Aselby ring showed it to consist of somewhat uneven but still decent-quality carbon steel. General conclusions should however not be drawn from a single observation. Here, we have sampled six Aselby rings for metallographic examination of the cross-sections. The material quality and carbon content of the sampled rings were found to be very uneven, and relatively large inclusions of unworked slag were common. We conclude that the rings were not bars of raw material. Instead, they may have been amulet rings, intended for ritual use. If so, our results suggest that the material properties of amulet rings may have been less important during rituals it may have sufficed that the rings had the right shape.

Place, publisher, year, edition, pages
Royal Academy Letters, History & Antiquities, 2018
National Category
Archaeology
Identifiers
urn:nbn:se:kth:diva-240251 (URN)000431744000001 ()
Note

QC 20190110

Available from: 2019-01-10 Created: 2019-01-10 Last updated: 2019-01-10Bibliographically approved
Persson, F., Eliasson, A. & Jönsson, P. G. (2014). Oxidation of Water Atomized Metal Powders. Steel Research International, 85(12), 1629-1638
Open this publication in new window or tab >>Oxidation of Water Atomized Metal Powders
2014 (English)In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 85, no 12, p. 1629-1638Article in journal (Refereed) Published
Abstract [en]

This study focuses on the oxidation of water atomized metal powders. Pilot plant experiments were performed using liquid iron alloyed with manganese and carbon. The powder particle shape and the oxides were determined using optical and scanning electron microscopy with energy dispersive X-ray microanalysis. The oxygen in the atomized powders was mainly present as thin surface oxide layers, which were determined to increase from 10 to 40-60 nm, at increased particle sizes from 10 to 750 mu m. In addition, manganese oxides were observed to be unevenly distributed at the surface of several particles for iron powders alloyed with 0.3mass% Mn. Experimental data indicated that between 10 and 20% of the manganese was present as oxides in the powders. However, equilibrium calculations predicted a strong driving force for oxidation of manganese. More specifically, it was estimated that only 4% of the initial manganese content remained in the final atomized powders.

Keywords
metal powders, atomization, oxidation
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-158283 (URN)10.1002/srin.201300466 (DOI)000345832000006 ()2-s2.0-84913617856 (Scopus ID)
Note

QC 20150109

Available from: 2015-01-09 Created: 2015-01-07 Last updated: 2017-12-05Bibliographically approved
Andersson, J., Raza, S., Eliasson, A. & Surreddi, K. B. (2014). Solidification of alloy 718, ati 718Plus® and waspaloy. In: 8th International Symposium on Superalloy 718 and Derivatives 2014: . Paper presented at 8th International Symposium on Superalloy 718 and Derivatives 2014, 28 September 2014 through 1 October 2014 (pp. 181-192).
Open this publication in new window or tab >>Solidification of alloy 718, ati 718Plus® and waspaloy
2014 (English)In: 8th International Symposium on Superalloy 718 and Derivatives 2014, 2014, p. 181-192Conference paper, Published paper (Refereed)
Abstract [en]

Alloy 718, ATI 718Plus® and Waspaloy have been investigated in terms of what their respective solidification process reveals. Differential thermal analysis was used to approach the task together with secondary electron and back scattered electron detectors equipped with an energy dispersive X-ray spectroscopy detector. These experimental methods were used to construct pseudo binary phase diagrams that could aid in explaining solidification as well as liquation mechanisms in processes such as welding and casting. Furthermore, it was seen that Waspaloy has the smallest solidification range, followed by Alloy 718, and finally ATI 718Plus® possessing the largest solidification interval in comparison.

Keywords
Differential thermal analysis, Solidification, Superalloys, Alloys, Energy dispersive spectroscopy, Thermoanalysis, X ray spectroscopy, Backscattered electrons, Energy dispersive X ray spectroscopy, Experimental methods, Pseudo-binaries, Secondary electrons, Solidification interval, Solidification of alloys, Solidification process
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-167542 (URN)2-s2.0-84923071332 (Scopus ID)9781634396424 (ISBN)
Conference
8th International Symposium on Superalloy 718 and Derivatives 2014, 28 September 2014 through 1 October 2014
Note

QC 20150609

Available from: 2015-06-09 Created: 2015-05-22 Last updated: 2016-12-05Bibliographically approved
Andersson, J., Raza, S., Eliasson, A. & Surreddi, K. B. (2014). SOLIDIFICATION OF ALLOY 718, ATI 718PLUS (R) AND WASPALOY. In: Ott, E Banik, A Andersson, J Dempster, I Gabb, T Groh, J Heck, K Helmink, R Liu, X WusatowskaSarnek, A (Ed.), 8TH INTERNATIONAL SYMPOSIUM ON SUPERALLOY 718 AND DERIVATIVES: . Paper presented at 8TH INTERNATIONAL SYMPOSIUM ON SUPERALLOY 718 AND DERIVATIVES (pp. 181-192). JOHN WILEY & SONS INC
Open this publication in new window or tab >>SOLIDIFICATION OF ALLOY 718, ATI 718PLUS (R) AND WASPALOY
2014 (English)In: 8TH INTERNATIONAL SYMPOSIUM ON SUPERALLOY 718 AND DERIVATIVES / [ed] Ott, E Banik, A Andersson, J Dempster, I Gabb, T Groh, J Heck, K Helmink, R Liu, X WusatowskaSarnek, A, JOHN WILEY & SONS INC , 2014, p. 181-192Conference paper, Published paper (Refereed)
Abstract [en]

Alloy 718, ATI 718Plus (R) and Waspaloy have been investigated in terms of what their respective solidification process reveals. Differential thermal analysis was used to approach the task together with secondary electron and back scattered electron detectors equipped with an energy dispersive X-ray spectroscopy detector. These experimental methods were used to construct pseudo binary phase diagrams that could aid in explaining solidification as well as liquation mechanisms in processes such as welding and casting. Furthermore, it was seen that Waspaloy has the smallest solidification range, followed by Alloy 718, and finally ATI 718Plus (R) possessing the largest solidification interval in comparison.

Place, publisher, year, edition, pages
JOHN WILEY & SONS INC, 2014
Keywords
Superalloys, Solidification, Differential Thermal Analysis
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-243804 (URN)000374558400015 ()
Conference
8TH INTERNATIONAL SYMPOSIUM ON SUPERALLOY 718 AND DERIVATIVES
Note

QC 20190206

Available from: 2019-02-06 Created: 2019-02-06 Last updated: 2019-02-06Bibliographically approved
Persson, F., Jönsson, P. G. & Eliasson, A. (2012). Influence of liquid metal properties for water atomised metal powders.
Open this publication in new window or tab >>Influence of liquid metal properties for water atomised metal powders
2012 (English)Manuscript (preprint) (Other academic)
Abstract [en]

The main focus of the present study was the influence of liquid metal properties on the particle size during water atomisation. Experiments for liquid iron showed that alloy additions of carbon and sulphur decreased the particle size. Moreover, it was indicated that the reduced d50 value at increased %C and %S may be related to a decreased viscosity and surface tension respectively. An alternative mechanism could be that raised superheats at increased carbon contents increased the total available time for atomisation. This may also have decreased the particle size. The influence of surface tension and viscosity on the d50 value was further analysed with a theoretical d50 model proposed in a previous work. A reduced viscosity from 4∙9 to 2∙1 mPa s decreased the d50 value with 33%. In addition, the particle size was estimated to decrease with 21% by decreasing the surface tension from 1840 to 900 mN m-1.

Publisher
p. 37
Keywords
water atomisation, metal powders, particle size, modelling, viscosity, surface tension
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-94531 (URN)
Note
QS 2012Available from: 2012-05-09 Created: 2012-05-09 Last updated: 2012-05-29Bibliographically approved
Persson, F., Eliasson, A. & Jönsson, P. G. (2012). Influence of liquid metal properties on water atomised iron powders. ISIJ International, 52(12), 2130-2138
Open this publication in new window or tab >>Influence of liquid metal properties on water atomised iron powders
2012 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 52, no 12, p. 2130-2138Article in journal (Refereed) Published
Abstract [en]

The main focus of the present study was the influence of liquid metal properties on the particle size during water atomisation. Experiments for liquid iron showed that alloy additions of carbon and sulphur decreased the particle size. Moreover, it was indicated that the reduced d50 value at increased %C and %S contents may be related to a decreased viscosity and surface tension respectively. An alternative mechanism could be that raised superheats at increased carbon contents increased the total available time for atomisation. This may also have decreased the particle size. The influence of surface tension and viscosity on the d50 value was further analysed with a theoretical d50 model proposed in a previous work. A reduced viscosity from 6.8 to 4.3 mPa s decreased the d50 value with 33%. In addition, the particle size was estimated to decrease with 27% by decreasing the surface tension from 1 850 to 900 mN m-1.

Keywords
Metal powders, Particle size, Superheat, Surface tension, Viscosity, Water atomisation
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-116149 (URN)10.2355/isijinternational.52.2130 (DOI)000312968000003 ()2-s2.0-84871778211 (Scopus ID)
Note

QC 20130118

Available from: 2013-01-18 Created: 2013-01-16 Last updated: 2017-12-06Bibliographically approved
Persson, F., Eliasson, A. & Jönsson, P. (2012). Prediction of particle size for water atomised metal powders: parameter study. Powder Metallurgy, 55(1), 45-53
Open this publication in new window or tab >>Prediction of particle size for water atomised metal powders: parameter study
2012 (English)In: Powder Metallurgy, ISSN 0032-5899, E-ISSN 1743-2901, Vol. 55, no 1, p. 45-53Article in journal (Refereed) Published
Abstract [en]

This work aims to investigate how some significant atomising parameters influence the mass median particle size d50 of water atomised metal powders. More specifically, these were water pressure, melt flowrate, water jet angle, liquid metal viscosity and surface tension. Existing models for the prediction of d50 during water atomisation were reviewed. The selected models were fitted and compared with atomising experiments of liquid iron containing 0.5–4.4%C. Experimental results and model calculations were used in a parameter study to investigate how the different parameters influenced d50. The effect on d50 was large for the water pressure, medium for the viscosity and low for the melt flowrate and surface tension. Model calculations indicate that the jet angle has a large effect on d50, which should be verified by additional studies. The model proposed by Bergquist (B. Bergquist: Powder Metall., 1999, 42, 331–343) showed the best agreement with the current experimental data.

Keywords
Powder metallurgy, Modelling, Water atomisation, Metal powder, Particle size
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-53622 (URN)10.1179/1743290111Y.0000000016 (DOI)000302546300008 ()
Note
QC 20120528Available from: 2011-12-29 Created: 2011-12-29 Last updated: 2017-12-08Bibliographically approved
Ragnarsson, L., Ek, M., Eliasson, A. & Du, S. (2010). Flow pattern in ingot during mould filling and its impact on inclusion removal. Ironmaking & steelmaking, 37(5), 347-352
Open this publication in new window or tab >>Flow pattern in ingot during mould filling and its impact on inclusion removal
2010 (English)In: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 37, no 5, p. 347-352Article in journal (Refereed) Published
Abstract [en]

A two-dimensional non-steady state computational fluid dynamic model was employed to gain a basic understanding of the flow in the ingot during casting. The surface velocity was found to be affected by the inlet angle and was found to vary with the casting level. The information of surface velocity was related to the probability of the inclusion removal. Water model experiments were also conducted to help the understanding. The model calculation revealed the same trends as the results of water model experiments. Both computational fluid dynamic data and the physical modelling showed that the inlet angle of 5 degrees currently used in the industry was a good alternative regarding inclusion removal. The present work suggests strongly that the melting shop should try to obtain a liquid or semiliquid film at as early stage as possible in ingot casting.

Keywords
Inclusions, Casting powder, Ingot casting, Cold model, CFD
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-13398 (URN)10.1179/030192310X12683045806062 (DOI)000280123300006 ()2-s2.0-77954705959 (Scopus ID)
Note
QC 20100617 Uppdaterad från accepted till published (20110208). Tidigare titel: "Flow pattern in the ingot during mould filling and its impact on inclusion removal"Available from: 2010-06-17 Created: 2010-06-17 Last updated: 2017-12-12Bibliographically approved
Eliasson, A., Ekbom, L. & Fredriksson, H. (2008). Tungsten grain separation during initial stage of liquid phase sintering. Powder Metallurgy, 51(4), 343-349
Open this publication in new window or tab >>Tungsten grain separation during initial stage of liquid phase sintering
2008 (English)In: Powder Metallurgy, ISSN 0032-5899, E-ISSN 1743-2901, Vol. 51, no 4, p. 343-349Article in journal (Refereed) Published
Abstract [en]

The initial stage, the first few seconds of liquid phase sintering has been investigated in experiments using a tungsten heavy alloy with low tungsten content. The heavy alloy has been melted in a temperature gradient for short periods, similar to 9 s in an ellipsoid mirror furnace. During the liquid phase sintering at about 1470 degrees C, a penetration followed by a remarkably rapid separation and dispersion of the tungsten grains by the molten matrix occur. The suggested explanation for this grain separation and dispersion is based on the effect of composition gradients in the liquid matrix and a theory based on interagglomerate melt swelling due to a Kirkendall effect.

Keywords
Liquid phase sintering, Heavy metal, Particle composites, Tungsten, Agglomerate separation, Kirkendall effect, diffusion, penetration, growth
Identifiers
urn:nbn:se:kth:diva-18149 (URN)10.1179/174329008x293732 (DOI)000263029100029 ()2-s2.0-65549145046 (Scopus ID)
Note
QC 20100525Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2017-12-12Bibliographically approved
Eliasson, A. & Fredriksson, H. (2007). Interaction behaviour between alumina particles and solidification front and particle behaviour in iron based alloys at deoxidation by Kirkendall effect. International Journal of Cast Metals Research, 20(3), 127-130
Open this publication in new window or tab >>Interaction behaviour between alumina particles and solidification front and particle behaviour in iron based alloys at deoxidation by Kirkendall effect
2007 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 20, no 3, p. 127-130Article in journal (Refereed) Published
Abstract [en]

The present paper deals with interaction phenomena by particles in liquid metals. The interpretation is to make an initial analysis how the model by Kirkendall, for diffusion phenomena in solids, can be used for the analysis of particle behaviour in liquids. Whenever there is an unequal solutal field, insoluble particles may 'move' due to concentration gradients in the liquid and a difference of diffusion rates of the solute atoms. The analysis deals with the following melt/particles interactions: one is the interaction behaviour between the solidification front and the formed slag oxide particles of Al2O3 and the critical velocity for pushing/engulfment at the interface and the other is the movement and clustering of precipitated alumina inclusions around SiO2 or FeO inclusions formed in a steel melt before deoxidation. Despite the uncertainty of the used material constants and the assumed concentration profiles, the results of the present study are in accordance with some shown experimental particle movements.

Keywords
Kirkendall effect, particle interaction, pushing, engulfment, clustering, deoxidation, solid-liquid interface, critical velocity, solid/liquid interface, monoatomic liquids, structural model, engulfment, diffusion, melt
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-17192 (URN)10.1179/136404607X239762 (DOI)000251991700006 ()2-s2.0-37249052430 (Scopus ID)
Note
5th Decennial International Conference on Solidification Processing Location: Univ Sheffield, Sheffield, England, Date: JUL 23-25, 2007Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2017-12-12Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0864-3679

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