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Publications (5 of 5) Show all publications
Balachandramurthi, A. R. & Olsson, J. (2019). Microstructure tailoring in Electron Beam Powder Bed Fusion Additive Manufacturing and its potential consequences. Results in Materials, 1
Open this publication in new window or tab >>Microstructure tailoring in Electron Beam Powder Bed Fusion Additive Manufacturing and its potential consequences
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2019 (English)In: Results in Materials, ISSN 2590-048X, Vol. 1Article in journal (Refereed) Published
Abstract [en]

Electron Beam Powder Bed Fusion process for Alloy 718 was investigated, in the sense of microstructural evolution with varying process conditions. The existence of a geometric relationship between the melt front and the processing parameters was observed. By understanding and capitalizing on this relationship, it was possible to obtain columnar, equiaxed or bimodal microstructure.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Alloy 718, Texture, Microstructure, Additive manufacturing, Powder bed fusion
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-14331 (URN)10.1016/j.rinma.2019.100017 (DOI)
Available from: 2019-08-26 Created: 2019-08-26 Last updated: 2019-08-26Bibliographically approved
Tofeldt, O., Pierce, S., Smillie, G., Kerr, W., Flockhart, G., Macleod, C., . . . McMahon, D. (2018). Investigation of fundamental ultrasonic propagation characteristics in NDT of Electron Beam Melted additive manufactured samples: Inconel 718. In: : . Paper presented at 12th European Conference on Non-Destructive Testing (ECNDT 2018), June 11-15, Gothenburg, 2018 (pp. 1-4).
Open this publication in new window or tab >>Investigation of fundamental ultrasonic propagation characteristics in NDT of Electron Beam Melted additive manufactured samples: Inconel 718
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2018 (English)Conference paper, Published paper (Other academic)
Abstract [en]

New approaches for efficient NDT inspection of modern additively manufactured metallic components are required urgently to qualify and validate the next generation of metallic parts across a range of industries. Ultrasonic testing is a fundamental component of NDT for such additive manufacturing processes. This work studies the ultrasonic propagation characteristics of EBM manufactured sample coupons in Inconel 718material. Fundamental longitudinal and shear wave velocity measurements are experimentally measured in 3 orthogonal build directions of the sample coupons. Results show a dependency of the ultrasonic velocities and the build direction. The measured velocities are further verified in a phased array measurement showing successful results that highlights the potential of continued studies with synthetic apertures techniques.

Keywords
Propagagation and scattering, Ultrasonics
National Category
Metallurgy and Metallic Materials Composite Science and Engineering
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-12915 (URN)
Conference
12th European Conference on Non-Destructive Testing (ECNDT 2018), June 11-15, Gothenburg, 2018
Projects
Suman-next 400151
Available from: 2018-09-18 Created: 2018-09-18 Last updated: 2018-09-18Bibliographically approved
Karimi Neghlani, P., Deng, D., Sadeghimeresht, E., Olsson, J., Ålgårdh, J. & Andersson, J. (2018). Microstructure Development in Track-by-Track Melting of EBM-Manufactured Alloy 718. In: Ott, E., Liu, X., Andersson, J., Bi, Z., Bockenstedt, K., Dempster, I., Groh, J., Heck, K., Jablonski, P., Kaplan, M., Nagahama, D. and Sudbrack, C. (Ed.), Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications. Paper presented at 9th International Symposium on Superalloy 718 & Derivatives, Energy, Aerospace, and Industrial Applications, Pittsburgh, Pennsylvania, USA, 3-6 June, 2018 (pp. 643-654). Springer
Open this publication in new window or tab >>Microstructure Development in Track-by-Track Melting of EBM-Manufactured Alloy 718
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2018 (English)In: Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications / [ed] Ott, E., Liu, X., Andersson, J., Bi, Z., Bockenstedt, K., Dempster, I., Groh, J., Heck, K., Jablonski, P., Kaplan, M., Nagahama, D. and Sudbrack, C., Springer, 2018, p. 643-654Conference paper, Published paper (Refereed)
Abstract [en]

Electron beam melting (EBM) is a powder-bed fusion process within the group of additive manufacturing (AM) technology that is used to fabricate high performance metallic parts. Nickel-Iron base superalloys, such as Alloy 718, are subjected to successive heating and cooling at temperatures in excess of 800 °C during the EBM process. Characterization of the dendritic structure, carbides, Laves and δ-phase were of particular interest in this study. These successive thermal cycles influence the microstructure of the material resulting in a heterogeneous structure, especially in the building direction. Hence, the aim of this study was to gain increased fundamental understanding of the relationship between the processing history and the microstructure formed within a single layer. Different numbers of tracks with equal heights were for this purpose produced, varying from one to ten tracks. All tracks used the same process parameters regardless of number and/or position. Microstructure characteristics (sub-grain structure, grain structure and phases) were analyzed by optical microscopy, scanning electron microscopy equipped with energy disperse spectroscopy and electron backscatter diffraction. The direction of dendrites changed in the overlap zones within the tracks due to re-melting of material in the overlap zone. The primary dendrite arm spacings slightly increased along multi-tracks owing to a slight decrease in cooling rate by addition of the next tracks. Epitaxial growth of grains were observed in all samples due to partial re-melting of grains in previous layers and surface nucleation was also found to occur in all tracks.

Place, publisher, year, edition, pages
Springer, 2018
Series
The Minerals, Metals & Materials Series, ISSN 2367-1181, E-ISSN 2367-1696
Keywords
Additive manufacturing, Electron beam melting, Alloy 718, Microstructure, Track-by-Track
National Category
Metallurgy and Metallic Materials Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-12345 (URN)10.1007/978-3-319-89480-5_42 (DOI)978-3-319-89479-9 (ISBN)978-3-319-89480-5 (ISBN)
Conference
9th International Symposium on Superalloy 718 & Derivatives, Energy, Aerospace, and Industrial Applications, Pittsburgh, Pennsylvania, USA, 3-6 June, 2018
Note

First Online: 13 May 2018

Available from: 2018-10-26 Created: 2018-10-26 Last updated: 2019-04-03Bibliographically approved
Goel, S., Olsson, J., Ahlfors, M., Klement, U. & Joshi, S. V. (2018). The Effect of Location and Post-treatment on the Microstructure of EBM-Built Alloy 718. In: Ott, E., Liu, X., Andersson, J., Bi, Z., Bockenstedt, K., Dempster, I., Groh, J., Heck, K., Jablonski, P., Kaplan, M., Nagahama, D. and Sudbrack, C. (Ed.), Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications. Paper presented at 9th International Symposium on Superalloy 718 & Derivatives, Energy, Aerospace, and Industrial Applications, Pittsburgh, Pennsylvania, USA, 3-6 June, 2018 (pp. 115-129). Springer
Open this publication in new window or tab >>The Effect of Location and Post-treatment on the Microstructure of EBM-Built Alloy 718
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2018 (English)In: Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications / [ed] Ott, E., Liu, X., Andersson, J., Bi, Z., Bockenstedt, K., Dempster, I., Groh, J., Heck, K., Jablonski, P., Kaplan, M., Nagahama, D. and Sudbrack, C., Springer, 2018, p. 115-129Conference paper, Published paper (Refereed)
Abstract [en]

Additive manufacturing (AM) of Ni-based superalloys such as Alloy 718 may obviate the need for difficult machining and welding operations associated with geometrically intricate parts, thus potentially expanding design possibilities and facilitating cost-effective manufacture of complex components. However, processing AM builds completely free from defects, which may impair mechanical properties such as fatigue and ductility, is challenging. Anisotropic properties, microstructural heterogeneities and local formation of undesired phases are additional concerns that have motivated post-treatment of AM builds. This work investigates the microstructural changes associated with post-treatment of Alloy 718 specimens produced by Electron Beam Melting (EBM) for as-built microstructures at 3 build heights: near base plate, in the middle of build and near the top of the build. Two different post-treatment conditions, hot isostatic pressing (HIP) alone and a combined HIP with solutionising and two-step aging were examined and compared to the results for the as-built condition. The influence of various post-treatments on minor phase distributions (δ, γ″, carbides), overall porosity, longitudinal grain widths and Vickers microhardness was considered. The HIP treatment led to significant reduction in overall porosity and dissolution of δ phase, which led to appreciable grain growth for both post-treatment conditions. The variation in hardness noted as a function of build height for the as-built specimens was eliminated after post-treatment. Overall, the hardness was found to decrease after HIP and increase after the full HIP, solutionising and aging treatment, which was attributed to dissolution of γ″ during HIP and its re-precipitation in subsequent heat treatment steps.

Place, publisher, year, edition, pages
Springer, 2018
Series
The Minerals, Metals & Materials Series, ISSN 2367-1181, E-ISSN 2367-1696
Keywords
Additive manufacturing, Electron beam melting, Alloy 718, HIP, Heat treatment, Microstructure, XRD, Hardness, δ, γ″, Carbide
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-12346 (URN)10.1007/978-3-319-89480-5_6 (DOI)978-3-319-89479-9 (ISBN)978-3-319-89480-5 (ISBN)
Conference
9th International Symposium on Superalloy 718 & Derivatives, Energy, Aerospace, and Industrial Applications, Pittsburgh, Pennsylvania, USA, 3-6 June, 2018
Available from: 2018-10-26 Created: 2018-10-26 Last updated: 2019-02-18Bibliographically approved
Augustsson, S., Olsson, J., Gustavsson Christiernin, L. & Bolmsjö, G. (2014). How to Transfer Information Between Collaborating Human Operators and Industrial Robots in an Assembly. In: Proceedings the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational. Paper presented at NordiCHI '14 Proceedings of the 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational (pp. 286-294). ACM Publications
Open this publication in new window or tab >>How to Transfer Information Between Collaborating Human Operators and Industrial Robots in an Assembly
2014 (English)In: Proceedings the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational, ACM Publications, 2014, p. 286-294Conference paper, Published paper (Refereed)
Abstract [en]

Flexible human-robot industrial coproduction will be important in many small and middle-sized companies in the future. One of the major challenges in a flexible robot cell is how to transfer information between the human and the robot with help of existing and safety approved equipment. In this paper a case study will be presented where the first half focus on data transfer to the robot communicating the human's position and movements forcing the robot to respond to the triggers. The second half focuses on how to visualize information about the settings and assembly order to the human. The outcome was successful and flexible, efficient coproduction could be achieved but also a number of new challenges were found.

Place, publisher, year, edition, pages
ACM Publications, 2014
Keywords
coproduction, human-robot interaction, industrial assembly, information transfer
National Category
Robotics
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-6874 (URN)10.1145/2639189.2639243 (DOI)2-s2.0-84911458351 (Scopus ID)978-1-4503-2542-4 (ISBN)
Conference
NordiCHI '14 Proceedings of the 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational
Available from: 2014-10-20 Created: 2014-10-20 Last updated: 2018-08-12Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0462-0912

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