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Jansson, A. & Pejryd, L. (2019). Dual-energy computed tomography investigation of additive manufacturing aluminium: carbon-fibre composite joints. Heliyon, 5(2), Article ID e01200.
Open this publication in new window or tab >>Dual-energy computed tomography investigation of additive manufacturing aluminium: carbon-fibre composite joints
2019 (English)In: Heliyon, ISSN 2405-8440, Vol. 5, no 2, article id e01200Article in journal (Refereed) Published
Abstract [en]

In this work, aluminium–carbon-fibre reinforced plastic joints have been studied. Three types of samples were designed as double lap joints where the aluminium inserts were fabricated using both classical methods (milling) and additive manufacturing. Two versions of the joint were fabricated using additive manufacturing, one flat, and the other with small teeth designed to hook into the carbon-fibre plies. The joints were characterised using a non-linear, dual-energy computed tomography method to evaluate the bond between the composite and the metal inserts. The mechanical strength of the bonds was evaluated, both through tensile tests and four-point bending. A simple finite element model was used to discuss the joints behaviour. It was found that the joints fabricated using additive manufactured inserts were more resistant to peel stress than the milled inserts. In four-point bending tests the moment that the joint could withstand was increased by roughly 300% with the use of additive manufacturing and 400% with the use of additive manufacturing and small teeth. However, in tensile tests it was found that the teeth design reduced the maximum load capacity of the joints by roughly 30% due to porosity. Further, it was found that the additive manufactured samples did not add to the capability of withstanding shearstress. The information gained with the dual-energy computed tomography method was highly valuable as the behaviour of the joints would have been difficult to explain without the porosity information.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Mechanical engineering, Materials science
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-72142 (URN)10.1016/j.heliyon.2019.e01200 (DOI)000460082200023 ()30839940 (PubMedID)2-s2.0-85061013958 (Scopus ID)
Available from: 2019-02-05 Created: 2019-02-05 Last updated: 2019-06-19Bibliographically approved
Jansson, A. & Pejryd, L. (2019). In-situ computed tomography investigation of the compression behaviour of strut, and periodic surface lattices. In: Rolf Diederichs (Ed.), iCT 2019: . Paper presented at 9th Conference on Industrial Computed Tomography (iCT) 2019, 13-15 Feb, 2019, Padova, Italy (pp. 221-227). NDT.net
Open this publication in new window or tab >>In-situ computed tomography investigation of the compression behaviour of strut, and periodic surface lattices
2019 (English)In: iCT 2019 / [ed] Rolf Diederichs, NDT.net , 2019, p. 221-227Conference paper, Published paper (Refereed)
Abstract [en]

In this work the effects of fabrication errors in the Body Centered Cubic strut lattice, and the periodic surface lattice Schwarz Diamond has been investigated. The lattices were both fabricated as-is and with induced errors to evaluate the lattices response to fabrication errors. The behaviour of the lattices were studied using compression test and in-situ computed tomography investigation. The results show that the Schwarz Diamond lattices in general are stronger than the Body Centered Cubic lattices in all of the measured aspects. Often up to five times stronger. It was also found that the elastic behaviour of the Schwarz Diamond lattices were mainly unaffected by fabrication errors while the Body Centered Cubic lattices experienced severe losses in performance. The behaviour of the lattices under compression could be followed using computed tomography which aided in the understanding of their behaviour.

Place, publisher, year, edition, pages
NDT.net, 2019
Keywords
Additive manufacturing, computed tomography, periodic surface lattices, in-situ compression, fabrication error
National Category
Engineering and Technology Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-72514 (URN)
Conference
9th Conference on Industrial Computed Tomography (iCT) 2019, 13-15 Feb, 2019, Padova, Italy
Available from: 2019-02-18 Created: 2019-02-18 Last updated: 2019-06-13
Zekavat, A. R., Jansson, A., Larsson, J. & Pejryd, L. (2019). Investigating the effect of fabrication temperature on mechanical properties of fused deposition modelling parts using X-ray computed tomography. The International Journal of Advanced Manufacturing Technology, 100(1-4), 287-296
Open this publication in new window or tab >>Investigating the effect of fabrication temperature on mechanical properties of fused deposition modelling parts using X-ray computed tomography
2019 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 100, no 1-4, p. 287-296Article in journal (Refereed) Published
Abstract [en]

Fused deposition modeling (FDM) is one of the most common additive manufacturing (AM) techniques for fabricating prototypes as well as functional parts. In this technique, several parameters may influence the part quality and consequently mechanical properties of fabricated components. In this paper, an experimental investigation on effects of fabrication temperature as one of the influential parameters on mechanical properties of manufactured parts is presented. A series of specimens fabricated at temperatures ranging from 180 to 260 C were used for this investigation. X-ray computed tomography (CT) was used in order to non-destructively analyze the internal geometry of the specimens especially the bond between extruded filaments. Finally, the specimens were subjected to a uniaxial tensile load for evaluation of mechanical properties. The results showed that the specimens fabricated at lower temperatures have relatively lower tensile strength despite their considerably higher strain at break. In addition, the specimens fabricated at higher temperature range had significantly higher tensile strength because of the better bond between extruded filaments. The different mechanical responses were highly related to the internal geometry of the specimens and not necessarily the porosity. CT showed great potential as a non-destructive tool for investigation and development of FDM process.

Place, publisher, year, edition, pages
Springer London, 2019
Keywords
Fused deposition modeling, Computed tomography, Polylactic acid, Additive manufacturing
National Category
Other Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-69110 (URN)10.1007/s00170-018-2664-8 (DOI)000455946000025 ()2-s2.0-85053832455 (Scopus ID)
Available from: 2018-09-28 Created: 2018-09-28 Last updated: 2019-08-27Bibliographically approved
Larsson, J., Karlsson, P. & Pejryd, L. (2019). The effect of bearing length on the surface quality of drawn wire. In: : . Paper presented at 89th Annual Convention of the Wire Association International, Atlanta, USA, May 13-16, 2019.
Open this publication in new window or tab >>The effect of bearing length on the surface quality of drawn wire
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

In wire drawing, the geometry of drawing dies influences the performance of the wire process. This study investigates the effect of bearing lengths on the surface quality of the drawn wire. Wire drawing tests were done using an industrial wiredrawing machine utilizing drawing dies with different bearing lengths. The influence of bearing length on surface quality is discussed.

Keywords
Wire, Bearing length, Wire drawing
National Category
Mechanical Engineering Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-75164 (URN)
Conference
89th Annual Convention of the Wire Association International, Atlanta, USA, May 13-16, 2019
Available from: 2019-07-19 Created: 2019-07-19 Last updated: 2019-07-25Bibliographically approved
Pejryd, L. & Larsson, J. (2018). Additively manufactured tool holder for wire drawing processes. In: EURO PM2018 Congress Proceedings: . Paper presented at Europe's Annual Powder Metallurgy Congress and Exhibition (EURO PM2018), Bilbao, Spain, October 14-18, 2018. EPMA, Article ID 3987660.
Open this publication in new window or tab >>Additively manufactured tool holder for wire drawing processes
2018 (English)In: EURO PM2018 Congress Proceedings, EPMA , 2018, article id 3987660Conference paper, Published paper (Refereed)
Abstract [en]

Manufacturing of wires, where metal rods and/or wire are drawn through a series of dies to produce the final dimensions, generates heat in the tool. The cemented carbide tool is enclosed in a tool holder of steel that also serves as a cooling body. Earlier work have shown that reducing the temperature of the tool through the tool holder may lead to increased life time for the tool. In this work, the additive manufacturing technique (AM) selective laser melting was used to produce a steel tool holder with conformal cooling channels, without having to take into account the restrictions of machining processes for the placement of these channels. The cooling capacity of the tool holder, was studied by experiments measuring temperature of the tool holder and of the cooling liquid as well as flow. A heating-probe having the shape of the tool, mimicking the thermal conditions of a wire drawing process, was used. The increased cooling was also compared to FEM modelling results.

Place, publisher, year, edition, pages
EPMA, 2018
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-70680 (URN)978-1-899072-50-7 (ISBN)
Conference
Europe's Annual Powder Metallurgy Congress and Exhibition (EURO PM2018), Bilbao, Spain, October 14-18, 2018
Available from: 2018-12-11 Created: 2018-12-11 Last updated: 2018-12-17Bibliographically approved
Zekavat, A. R., Pejryd, L. & Gundlach, C. (2018). Effect of X-Ray Computed Tomography Magnification on Porosity Analysis of Additively Manufactured Parts. In: World PM2018 Congress Proceedings: . Paper presented at 2018 World Congress on Powder Metallurgy (WORLDPM2018), Beijing, China, September 16-20, 2018.
Open this publication in new window or tab >>Effect of X-Ray Computed Tomography Magnification on Porosity Analysis of Additively Manufactured Parts
2018 (English)In: World PM2018 Congress Proceedings, 2018Conference paper, Published paper (Refereed)
Abstract [en]

X-ray computed tomography has been widely used for inspection of parts manufactured using additive manufacturing (AM) and powder metallurgy (PM). The ability of this method to non-destructively evaluate the porosity content of parts fabricated using AM and PM has made it a reliable method for such inspection. The results obtained from this method are highly dependent on CT acquisition parameters such as the magnification (resolution) at which the part has been scanned. Depending on the size of the parts the scan might need to be performed at lower magnifications which results in loss of information for porosity analysis. Therefore the effect of changing CT magnification on the obtained porosity of an additively manufactured specimen made of AlSi10Mg is investigated in this study. The specimen was scanned at various magnifications resulting in data sets with different resolutions. The porosity content was measured for each data set and the results showed that the porosity measurement using CT is highly dependent on the magnification (resolution) at which the data sets are acquired. The results from this study provided essential information about the porosity content which should be expected depending on the CT magnification.

Keywords
Porosity, X-ray computed tomography (CT), Additive manufacturing (AM)
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-69047 (URN)
Conference
2018 World Congress on Powder Metallurgy (WORLDPM2018), Beijing, China, September 16-20, 2018
Available from: 2018-09-25 Created: 2018-09-25 Last updated: 2019-08-28Bibliographically approved
Zekavat, A. R., Jansson, A., Gundlach, C. & Pejryd, L. (2018). Effect of X-ray Computed Tomography Magnification on Surface Morphology Investigation of Additive Manufacturing Surfaces. In: 8th Conference on Industrial Computed Tomography: . Paper presented at iCT conference 2018, Wels, Austria, 7 February, 2018.
Open this publication in new window or tab >>Effect of X-ray Computed Tomography Magnification on Surface Morphology Investigation of Additive Manufacturing Surfaces
2018 (English)In: 8th Conference on Industrial Computed Tomography, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Additive manufacturing (AM) in the last decade has become a widespread manufacturing process. The possibilities that such technologies have provided for manufacturing of complex geometries compared to conventional manufacturing processes has made them popular in many branches of industry. Despite the advantages of these methods, there are limiting issues which needs to be thoroughly investigated. A limiting factor, especially for powder bed AM parts is their undesired surface finish. AM surfaces can be investigated using various methods such as optical or tactile methods, however for complex AM surfaces they are incapable of capturing all details such as deep valleys at surface level. X-ray computed tomography (CT), can provide 3D information of complex AM surfaces and does not have limitations that line of sight and tactile methods have. There are several parameters in CT investigation, which can potentially alter the obtained results. Depending on the CT magnification at which the data is acquired the result specifically surface level detail might be affected. The aim of this study is to investigate the effect of different CT magnifications on surface texture measurement of additively manufactured surfaces. Surface features, including highest peaks and deepest valleys contributing to maximum and minimum thickness of specimen from different magnifications were compared with each other. The result shows that, the lower magnification scans underestimate both peak and valley measurements in comparison to the highest magnification scan. Measurement of valleys and re-entrant features were underestimated at more considerable level. The results from this study provide some understanding regarding surface morphology assessment of AM parts and the level of detail which can be expected depending on the CT magnification.

Keywords
Computed tomography, Additive manufacturing, Surface texture
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-65426 (URN)
Conference
iCT conference 2018, Wels, Austria, 7 February, 2018
Available from: 2018-03-02 Created: 2018-03-02 Last updated: 2019-08-27Bibliographically approved
Pejryd, L. (2018). Evaluation of internal defects in additive manufactured metallic network structures by Computed Tomography. In: : . Paper presented at 8th International Conference in Industrial Computed Tomography (iCT), Wels, Austria, February 6-9, 2018. N D T Internet Publishing, Article ID 104.
Open this publication in new window or tab >>Evaluation of internal defects in additive manufactured metallic network structures by Computed Tomography
2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The ability to manufacture complex internal features is one of the distinct differentiators of Additive Manufacturing (AM) as compared to other manufacturing methods for metal components. This manufacturing process provide designers with new opportunities in the design, such as e.g. networks and curved and non round cooling channels. To fully take advantage of metal AM in industrial use, robust methods for the detection of potential internal defects is however needed. A method that holds the promise of being one of the few tools for non-destructive evaluation (NDE) of internal features and defects is X-ray computed tomography (CT). The applicability and limitations of CT, especially for defect determination in products with complex internal structures is however not fully understood. In this work, parts with different sizes of controlled internal defects in the form of slots of varying width, 0,1 – 0,4 mm was manufactured by AM, using Selective Laser melting (SLM). The parts were produced in both titanium and aluminium alloys and both with internal networks and as solid pieces. For both of the designed types of samples, containing the pre designed defects, the ability to detect the defects by industrial computed tomography (CT) was evaluated. The evaluation of defects using CT data can be done by a trained operator. For solid components this can be done with some assistance of analysis modes that are available in comersial software. For components with complex internal structures, the result is more operator dependant and more work is needed to develop methods for CT inspection that can enable automation of the inspection process and/or to assist a trained operator.

Place, publisher, year, edition, pages
N D T Internet Publishing, 2018
Series
E-Journal of Nondestructive Testing, E-ISSN 1435-4934
Keywords
Selective laser melting, aluminium, titanium, computed tomography
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-71470 (URN)
Conference
8th International Conference in Industrial Computed Tomography (iCT), Wels, Austria, February 6-9, 2018
Available from: 2019-01-15 Created: 2019-01-15 Last updated: 2019-01-21Bibliographically approved
El-Amine, K., Larsson, J. & Pejryd, L. (2018). Experimental comparison of roller die and conventional wire drawing. Journal of Materials Processing Technology, 257, 7-14
Open this publication in new window or tab >>Experimental comparison of roller die and conventional wire drawing
2018 (English)In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 257, p. 7-14Article in journal (Refereed) Published
Abstract [en]

In this work, the application of roller dies as an alternative to conventional dies in the wire drawing process – claimed in earlier works to offer many advantageous improvements – is evaluated. To this end, experimental procedures using a single stage drawing machine were conducted, drawing low and medium carbon steel wires using both roller dies and conventional dies. The two reduction processes were compared with respect to drawing force and the resulting wire temperature. Also the mechanical properties of the drawn wires were investigated. The obtained results have not shown any large differences between the two processes, and the main improvement using the roller die method was a better wire surface. This advantage was counteracted with downsides including higher wire temperature and lower strain at fracture.

Moreover, a formula to theoretically calculate drawing force for the conventional drawing process was modified and used to calculate drawing force for the two reduction steps in the roller die cassette. The results showed that the proportion of inhomogeneous deformation was much higher in the rolling process as compared to the conventional process.

In view of the outcomes in this work, the alternative of drawing wire through roller dies was not considered to be offering more improvements with respect to the conventional drawing method.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Wire drawing, Roller dies, Drawing dies, Carbon steel
National Category
Mechanical Engineering Metallurgy and Metallic Materials
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-65371 (URN)10.1016/j.jmatprotec.2018.02.012 (DOI)000431161400002 ()2-s2.0-85042386684 (Scopus ID)
Projects
NGWire
Funder
VINNOVA, 201303265
Note

Funding Agencies:

AB Sandvik Materials Technology  

Fagersta-Stainless AB  

FNsteel Hjulsbro AB  

Suzuki Garphyttan AB 

Available from: 2018-03-01 Created: 2018-03-01 Last updated: 2018-05-18Bibliographically approved
Surreddi, K. B., Oikonomou, C., Karlsson, P., Olsson, M. & Pejryd, L. (2018). In-situ micro-tensile testing of additive manufactured maraging steels in the SEM: Influence of build orientation, thickness and roughness on the resulting mechanical properties. La Metallurgia Italiana (3), 27-33
Open this publication in new window or tab >>In-situ micro-tensile testing of additive manufactured maraging steels in the SEM: Influence of build orientation, thickness and roughness on the resulting mechanical properties
Show others...
2018 (English)In: La Metallurgia Italiana, ISSN 0026-0843, no 3, p. 27-33Article in journal (Refereed) Published
Abstract [en]

Selective laser melting (SLM) is frequently used additive manufacturing technique capable of producing various complex parts including thin-wall sections. However the surface roughness is a limiting factor in thin sections produced by SLM process when strength is the main criterion. In this study, the influence of build orientation, thickness and roughness on the resulting mechanical properties of as-built test samples was investigated. Various thin sheets of EN 1.2709 maraging steel built in horizontal and vertical orientations produced by SLM were investigated using in-situ micro-tensile testing in a scanning electron microscope. The mechanical strength and deformation mechanisms were analyzed and explained based on thickness and build orientation. Increased ductility was observed in thicker samples as well as in the horizontal build samples. The results illustrate the potential of the in-situ test technique and aspects important to consider in design guidelines for thin AM structures.

Place, publisher, year, edition, pages
Associazione Italiana di Metallurgia, 2018
Keywords
selective laser melting, in-situ micro-tensile testing, build orientation, deformation mechanism and maraging steel
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:oru:diva-68092 (URN)000435488500005 ()
Projects
ATOAM
Funder
Knowledge Foundation
Available from: 2018-07-24 Created: 2018-07-24 Last updated: 2018-07-31Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1408-2249

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