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Andersson, Nils-EricORCID iD iconorcid.org/0000-0001-6445-6005
Publications (10 of 26) Show all publications
Jarfors, A. E. .., Shashidhar, A. C. G., Yepur, H. K., Steggo, J., Andersson, N.-E. & Stolt, R. (2021). Build strategy and impact strength of slm produced maraging steel (1.2709). Metals, 11(1), 1-20, Article ID 51.
Open this publication in new window or tab >>Build strategy and impact strength of slm produced maraging steel (1.2709)
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2021 (English)In: Metals, ISSN 2075-4701, Vol. 11, no 1, p. 1-20, article id 51Article in journal (Refereed) Published
Abstract [en]

The current paper aimed to study the impact properties of additively manufactured maraging steel (1.2709) using laser powder bed fusion (PBF-L) processing. The specimens were fabricated using 3D Systems ProX 300 equipment under constant specific power input, or Andrew number. The interactions between the build strategy and parameters such as hatch spacing and scan speed was, and the impact strength and fracture were investigated. The impact energy anisotropy was also investigated in parallel and perpendicular to the build direction. Instrumented impact testing was performed, and the fractography supported that the fusion zone geometry dictated the fracture behavior. The influence from gaseous elements such as nitrogen, oxygen, and hydrogen was found insignificant at the levels found in the printed material. 

Place, publisher, year, edition, pages
MDPI, 2021
Keywords
Additive manufacturing, Fracture, Hatch spacing, Impact energy, Process parameters, Scan speed
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-51488 (URN)10.3390/met11010051 (DOI)000610508400001 ()2-s2.0-85098650962 (Scopus ID)GOA (Local ID)GOA (Archive number)GOA (OAI)
Funder
Knowledge Foundation, 20160327
Available from: 2021-01-14 Created: 2021-01-14 Last updated: 2021-06-09Bibliographically approved
Dini, H., Andersson, N.-E. & Jarfors, A. E. .. (2021). Effect of Process Parameters on Distortion and Residual Stress in High-Pressure Die Cast AZ91D Components After Clean Blasting and Painting. International Journal of metalcasting, 15(1), 241-258
Open this publication in new window or tab >>Effect of Process Parameters on Distortion and Residual Stress in High-Pressure Die Cast AZ91D Components After Clean Blasting and Painting
2021 (English)In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 15, no 1, p. 241-258Article in journal (Refereed) Published
Abstract [en]

A high-pressure die-casting process was employed to produce AZ91D components. These cast components were exposed to three different post-treatments: (1) clean blasting, (2) clean blasting and painting, and (3) painting (without clean blasting). The influence of the process parameters first phase injection speed, temperature of fixed half of the die, cooling time, and intensification pressure on distortion and residual stress of the components after each post-treatment were investigated. The results showed that intensification pressure was the most significant factor among the four parameters.

Place, publisher, year, edition, pages
Springer, 2021
Keywords
Component casting, Distortion, High pressure die casting, Magnesium, Residual stress, Blasting, Die casting, Residual stresses, Cast components, Cooling time, Exposed to, High pressure die casts, Injection speed, Post treatment, Process parameters, High pressure effects
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-48749 (URN)10.1007/s40962-020-00448-9 (DOI)000522948700001 ()2-s2.0-85083194655 (Scopus ID)HOA;;1434517 (Local ID)HOA;;1434517 (Archive number)HOA;;1434517 (OAI)
Funder
Knowledge Foundation, 2010/0280
Available from: 2020-06-03 Created: 2020-06-03 Last updated: 2022-01-21Bibliographically approved
Salomonsson, K., Svoboda, A., Andersson, N.-E. & Jarfors, A. E. .. (2020). Modeling and Analysis of a Screw Fitting Assembly Process Involving a Cast Magnesium Component. Frontiers in Materials, 7, Article ID 534385.
Open this publication in new window or tab >>Modeling and Analysis of a Screw Fitting Assembly Process Involving a Cast Magnesium Component
2020 (English)In: Frontiers in Materials, ISSN 2296-8016, Vol. 7, article id 534385Article in journal (Refereed) Published
Abstract [en]

A finite element analysis of a complex assembly was made. The material description used was a physically based material model with dislocation density as an internal state variable. This analysis showed the importance of the materials’ behavior in the process as there is discrepancy between the bolt head contact pressure and the internals state of the materials where the assembly process allows for recovery. The end state is governed by both the tightening process and the thermal history and strongly influenced by the thermal expansion of the AZ91D alloy.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2020
Keywords
assembly, dislocation, finite element analysis, physically based modeling, screw fitting, thermal expansion
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-51571 (URN)10.3389/fmats.2020.534385 (DOI)000604600100001 ()2-s2.0-85098989391 (Scopus ID)GOA;;51571 (Local ID)GOA;;51571 (Archive number)GOA;;51571 (OAI)
Funder
Knowledge Foundation, 20100280,20170066
Available from: 2021-01-18 Created: 2021-01-18 Last updated: 2021-07-23Bibliographically approved
Eslami, M., Speranza, G., Fedel, M., Andersson, N.-E., Deflorian, F., Omanovic, S. & Zanella, C. (2019). Electropolymerization and possible corrosion protection effect of polypyrrole coatings on AA1050 (UNS A91050) in NaCl solutions. Corrosion, 75(7), 745-755
Open this publication in new window or tab >>Electropolymerization and possible corrosion protection effect of polypyrrole coatings on AA1050 (UNS A91050) in NaCl solutions
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2019 (English)In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 7, p. 745-755Article in journal (Refereed) Published
Abstract [en]

Effect of solution chemistry on the electropolymerization and the electrochemical properties of polypyrrole coatings on aluminum is studied by means of electrochemical techniques, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy. It is shown that the protection effect of the coating in long-term exposures and when exposed to more concentrated NaCl solutions depends on the chemistry of electropolymerization electrolyte. The results show that nitrate anions passivate the aluminum substrate during the electropolymerization process. The resulting coating is less prone to blistering in a NaCl solution and probably due to its higher electrochemical activity presents a higher anodic protection effect. The galvanic interaction of polypyrrole coating with aluminum in a NaCl solution is directly observed using focused ion beam-assisted SEM.

Place, publisher, year, edition, pages
National Association of Corrosion Engineers International, 2019
Keywords
Aluminum, Conductive polymer, Corrosion protection, Galvanic interaction, Passivation, Polypyrrole, Aluminum coatings, Aluminum corrosion, Anodic protection, Electrolytes, Electropolymerization, Galvanic corrosion, Ion beams, Polypyrroles, Scanning electron microscopy, Sodium chloride, X ray photoelectron spectroscopy, Aluminum substrate, Electrochemical activities, Electrochemical techniques, Long term exposure, Polypyrrole coatings, Solution chemistry, Corrosion resistant coatings
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-45537 (URN)10.5006/3124 (DOI)000474438600005 ()2-s2.0-85069675948 (Scopus ID)HOA JTH 2019;JTHMaterialIS (Local ID)HOA JTH 2019;JTHMaterialIS (Archive number)HOA JTH 2019;JTHMaterialIS (OAI)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-13Bibliographically approved
Keller, C., Zetterlind, M., Andersson, N.-E. & Ghassemali, E. (2019). Online labs in engineering education: Challenges and opportunities. In: : . Paper presented at The 15th international CDIO conference, 25-27 June 2019, Aarhus, Denmark.
Open this publication in new window or tab >>Online labs in engineering education: Challenges and opportunities
2019 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Engineering and Technology Educational Sciences
Identifiers
urn:nbn:se:hj:diva-58309 (URN)
Conference
The 15th international CDIO conference, 25-27 June 2019, Aarhus, Denmark
Available from: 2022-08-24 Created: 2022-08-24 Last updated: 2022-08-24Bibliographically 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
Dini, H., Svoboda, A., Andersson, N.-E., Ghassemali, E., Lindgren, L.-E. & Jarfors, A. E. .. (2018). Optimization and validation of a dislocation density based constitutive model for as-cast Mg-9%Al-1%Zn. Materials Science & Engineering: A, 710, 17-26
Open this publication in new window or tab >>Optimization and validation of a dislocation density based constitutive model for as-cast Mg-9%Al-1%Zn
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2018 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 710, p. 17-26Article in journal (Refereed) Published
Abstract [en]

A dislocation density-based constitutive model, including effects of microstructure scale and temperature, was calibrated to predict flow stress of an as-cast AZ91D (Mg-9%Al-1%Zn) alloy. Tensile stress-strain data, for strain rates from 10-4 up to 10-1 s-1 and temperatures from room temperature up to 190 °C were used for model calibration. The used model accounts for the interaction of various microstructure features with dislocations and thereby on the plastic properties. It was shown that the Secondary Dendrite Arm Spacing (SDAS) size was appropriate as an initial characteristic microstructural scale input to the model. However, as strain increased the influence of subcells size and total dislocation density dominated the flow stress. The calibrated temperature-dependent parameters were validated through a correlation between microstructure and the physics of the deforming alloy. The model was validated by comparison with dislocation density obtained by using Electron Backscattered Diffraction (EBSD) technique.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Casting methods, Characterization, Magnesium alloy, Optimization, Physically-based model, Plasticity, Aluminum, Aluminum alloys, Constitutive models, Magnesium castings, Microstructure, Plastic flow, Strain rate, Ternary alloys, Zinc, Zinc alloys, Zirconium alloys, Casting method, Dislocation densities, Electron back-scattered diffraction, Model calibration, Physically based modeling, Secondary dendrite arm spacing, Temperature dependent, Tensile stress strain, Magnesium alloys
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-38144 (URN)10.1016/j.msea.2017.10.081 (DOI)000429888200003 ()2-s2.0-85032297009 (Scopus ID)
Available from: 2017-12-12 Created: 2017-12-12 Last updated: 2018-09-21Bibliographically approved
Zamani, M., Dini, H., Svoboda, A., Lindgren, L.-E., Seifeddine, S., Andersson, N.-E. & Jarfors, A. (2017). A dislocation density based constitutive model for as-cast Al-Si alloys: Effect of temperature and microstructure. International Journal of Mechanical Sciences, 121, 164-170
Open this publication in new window or tab >>A dislocation density based constitutive model for as-cast Al-Si alloys: Effect of temperature and microstructure
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2017 (English)In: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162, Vol. 121, p. 164-170Article in journal (Refereed) Published
Abstract [en]

The flow stress of an as-cast Al-Si based alloy was modeled using a dislocation density based model. The developed dislocation density-based constitutive model describes the flow curve of the alloy with various microstructures at quite wide temperature range. Experimental data in the form of stress-strain curves for different strain rates ranging from 10−4 to 10−1 s−1 and temperatures ranging from ambient temperature up to 400 °C were used for model calibration. In order to model precisely the hardening and recovery process at elevated temperature, the interaction between vacancies and dissolved Si was included. The calibrated temperature dependent parameters for different microstructure were correlated to the metallurgical event of the material and validated. For the first time, a dislocation density based model was successfully developed for Al-Si cast alloys. The findings of this work expanded the knowledge on short strain tensile deformation behaviour of these type of alloys at different temperature, which is a critical element for conducting a reliable microstructural FE-simulation.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Aluminium cast alloy; Dislocation density; Eutectic phase; Si precipitation; Si solute; Vacancy concentration
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-27375 (URN)10.1016/j.ijmecsci.2017.01.003 (DOI)000395216300015 ()2-s2.0-85008703756 (Scopus ID)
Note

Finns som manuskript med titeln A Dislocation Density Based Yield Stress Model for as-cast EN AC-46000 Alloy i licentiatuppsats. 

Available from: 2015-06-22 Created: 2015-06-22 Last updated: 2017-12-12Bibliographically approved
Zhu, B., Fedel, M., Andersson, N.-E., Leisner, P., Deflorian, F. & Zanella, C. (2017). Effect of Si content and morphology on corrosion resistance of anodized cast Al-Si alloys. Journal of the Electrochemical Society, 164(7), C435-C441
Open this publication in new window or tab >>Effect of Si content and morphology on corrosion resistance of anodized cast Al-Si alloys
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2017 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 7, p. C435-C441Article in journal (Refereed) Published
Abstract [en]

This paper investigates the influence of Si content and Si particle morphology on the corrosion protection of anodized oxide layers on Al-Si alloys. Two Al alloys with low Si concentrations (2.43 wt-% and 5.45 wt-%, respectively) were studied and compared with 6082-T6 via electrochemical impedance spectroscopy (EIS) in 3 wt-% NaCl solution prior to oxide layer sealing. Si particles were also modified by the addition of Sr to study the influence of Si particle morphology on the corrosion protection of the oxide layer. The EIS showed that the corrosion protection provided by the oxide layer on Al-Si alloys is significantly affected by the presence of Si particles. Si particles make the oxide layer locally thinner and more defective in the eutectic region, thereby increasing the ease of substrate corrosion attack. However, the addition of Sr can improve the corrosion protection of anodized Al-Si alloys significantly. Furthermore, it was proved that higher Si level influences negatively the anodized oxide corrosion protection due to the higher amount of cracks and defects, but Sr modification is efficient in preventing this negative effect.

Place, publisher, year, edition, pages
The Electrochemical Society, 2017
Keywords
cast Al-Si alloys, anodising, EIS, 3D tomography
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-35095 (URN)10.1149/2.1631707jes (DOI)000404397300077 ()2-s2.0-85020855659 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Note

Part of licentiate thesis in its submitted form.

Available from: 2017-02-17 Created: 2017-02-17 Last updated: 2019-05-09Bibliographically approved
Zhu, B., Fedel, M., Andersson, N.-E., Leisner, P., Deflorian, F. & Zanella, C. (2017). Influence of the Sr modification and post-treatment on corrosion resistance of oxide layer of cast Al-(low)Si alloys. In: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017: . Paper presented at Joint European Corrosion Congress 2017, EUROCORR 2017 and 20th International Corrosion Congress and Process Safety Congress 2017; Prague; Czech Republic; 3 - 7 September 2017 (pp. 27-39). Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers
Open this publication in new window or tab >>Influence of the Sr modification and post-treatment on corrosion resistance of oxide layer of cast Al-(low)Si alloys
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2017 (English)In: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017, Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers , 2017, p. 27-39Conference paper, Published paper (Refereed)
Abstract [en]

The current development of casting process makes it possible to cast low Si content aluminium alloys, which open the gate for the application of anodising on cast aluminium components. This paper aims to investigate the influence of Sr modification as well as the post-treatment on corrosion resistance of oxide layer of low Si content cast Al alloys. In the present study, designed Al-Si alloys with 5.45 wt-% Si were studied by performing electrochemical impedance spectroscopy (EIS) in 3 wt-% NaCl solution. The morphology of Si particle was determined by controlling the level of Sr. The microstructure features were evaluated by optical microscopy and scanning electron microscopy (SEM). Furthermore, focus ion beam-SEM (FIB-SEM) equipped with energy-dispersive X-ray spectroscopy (EDXS) was applied to exam the corrosion morphology and the anodised layer with Si rich eutectic phases. The EIS study revealed that the corrosion resistance of the oxide layer on cast Al alloys can be significantly influenced by the morphology of Si particle and the post-treatment. It was found that the change of Si particle morphology from flake-like to fibrous by Sr addition can substantially improve the corrosion resistance of the oxide layer in the unsealed condition due to the formation of the more compacted oxide layer with less defects. Normally, the application of a sealing step such as the hydrothermal sealing can improve the corrosion protection of the oxide layer. However, in the current study, it was found the hydrothermal sealing step leads to a significant reduce of the corrosion protection due to the generation of cracks into the oxide layer, and the hydrothermal sealing step can counteract the improvement of the corrosion protection by Sr addition.

Place, publisher, year, edition, pages
Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers, 2017
Keywords
Anodising, Cast Al-Si alloys, Corrosion resistance, EIS, FIB-SEM, Aluminum alloys, Corrosion protection, Corrosion resistant alloys, Electrochemical corrosion, Electrochemical impedance spectroscopy, Energy dispersive spectroscopy, Ion beams, Morphology, Scanning electron microscopy, Silicon alloys, Sodium chloride, Strontium, Casting process, Corrosion morphology, Energy dispersive x-ray spectroscopy, FIB SEM, Hydrothermal sealing, Sr modification, Aluminum corrosion
National Category
Corrosion Engineering
Identifiers
urn:nbn:se:hj:diva-41534 (URN)2-s2.0-85052280685 (Scopus ID)
Conference
Joint European Corrosion Congress 2017, EUROCORR 2017 and 20th International Corrosion Congress and Process Safety Congress 2017; Prague; Czech Republic; 3 - 7 September 2017
Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2019-05-09Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-6445-6005

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