Mittuniversitetet

miun.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Macro- and Micromechanical Behavior of 316LN Lattice Structures Manufactured by Electron Beam Melting
Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kvalitets- och maskinteknik. (Sports Tech Research Centre)ORCID-id: 0000-0002-2543-2809
Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kvalitets- och maskinteknik. (Sports Tech Research Centre)
Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kvalitets- och maskinteknik. (Sports Tech Research Centre)ORCID-id: 0000-0002-9205-6807
Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kvalitets- och maskinteknik. (Sports Tech Research Centre)ORCID-id: 0000-0003-2964-9500
Visa övriga samt affilieringar
2019 (Engelska)Ingår i: Journal of materials engineering and performance (Print), ISSN 1059-9495, E-ISSN 1544-1024, Vol. 28, nr 12, s. 7290-7301Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

This work focuses on the possibility of processing stainless steel 316LN powder into lightweight structures using electron beam melting and investigates mechanical and microstructural properties in the material of processed components. Lattice structures conforming to ISO13314:2011 were manufactured using varying process parameters. Microstructure was examined using a scanning electron microscope. Compression testing was used to understand the effect of process parameters on the lattice mechanical properties, and nanoindentation was used to determine the material hardness. Lattices manufactured from 316L using EBM show smooth compression characteristics without collapsing layers and shear planes. The material has uniform hardness in strut shear planes, a microstructure resembling that of solid 316LN material but with significantly finer grain size, although slightly coarser sub-grain size. Grains appear to be growing along the lattice struts (e.g., along the heat transfer direction) and not in the build direction. Energy-dispersive x-ray spectroscopy analysis reveals boundary precipitates with increased levels of chromium, molybdenum and silicon. Studies clearly show that the 316LN grains in the material microstructure are elongated along the dominating heat transfer paths, which may or may not coincide with the build direction. Lattices made from a relatively ductile material, like 316LN, are much less susceptible to catastrophic collapse and show an extended range of elastic and plastic deformation. Tests indicate that EBM process for 316LN is stable allowing for both solid and lightweight (lattice) structures.

Ort, förlag, år, upplaga, sidor
2019. Vol. 28, nr 12, s. 7290-7301
Nyckelord [en]
316L additive manufacturing electron beam melting ISO 13314:2011 lattice nanoindentation
Nationell ämneskategori
Annan maskinteknik Annan maskinteknik
Identifikatorer
URN: urn:nbn:se:miun:diva-37818DOI: 10.1007/s11665-019-04484-3ISI: 000499641800002Scopus ID: 2-s2.0-85075894379OAI: oai:DiVA.org:miun-37818DiVA, id: diva2:1374677
Tillgänglig från: 2019-12-02 Skapad: 2019-12-02 Senast uppdaterad: 2023-09-19Bibliografiskt granskad
Ingår i avhandling
1. Process Development for Electron Beam Melting of 316LN Stainless Steel
Öppna denna publikation i ny flik eller fönster >>Process Development for Electron Beam Melting of 316LN Stainless Steel
2019 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Additive manufacturing (AM) is a technology that inverts the procedure of traditional machining. Instead of starting with a billet of material and removing unwanted parts, the AM manufacturing process starts with an empty workspace and proceeds to fill this workspace with material where it is desired, often in a layer-by-layer fashion. Materials available for AM processing include polymers, concrete, metals, ceramics, paper, photopolymers, and resins. This thesis is concerned with electron beam melting (EBM), which is a powder bed fusion technology that uses an electron beam to selectively melt a feedstock of fine powder to form geometries based on a computer-aided design file input. There are significant differences between EBM and conventional machining. Apart from the process differences, the ability to manufacture extremely complex parts almost as easily as a square block of material gives engineers the freedom to disregard complexity as a cost-driving factor. The engineering benefits of AM also include manufacturing geometries which were previously almost impossible, such as curved internal channels and complex lattice structures. Lattices are lightweight structures comprising a network of thin beams built up by multiplication of a three-dimensional template cell, or unit cell. By altering the dimensions and type of the unit cell, one can tailor the properties of the lattice to give it the desired behavior. Lattices can be made stiff or elastic, brittle or ductile, and even anisotropic, with different properties in different directions. This thesis focuses on alleviating one of the problems with EBM and AM, namely the relatively few materials available for processing. The method is to take a closer look at the widely used stainless steel 316LN, and investigate the possibility of processing 316LN powder via the EBM process into both lattices and solid material. The results show that 316LN is suitable for EBM processing, and a processing window is presented. The results also show that some additional work is needed to optimize the process parameters for increased tensile strength if the EBM-processed material is to match the yield strength of additively laser-processed 316L material.

Ort, förlag, år, upplaga, sidor
Sundsvall: Mid Sweden University, 2019. s. 39
Serie
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 164
Nyckelord
additive manufacturing, beam deflection rate, electron beam melting, energy input, material properties, microstructure, powder bed fusion, process parameters, 316LN stainless steel
Nationell ämneskategori
Annan maskinteknik
Identifikatorer
urn:nbn:se:miun:diva-37840 (URN)978-91-88947-25-3 (ISBN)
Presentation
2019-12-18, Q221, Akademigatan 1, 831 25 Östersund, 09:00 (Svenska)
Opponent
Handledare
Forskningsfinansiär
Interreg Sverige-Norge, TROJAM3DC
Anmärkning

Vid tidpunkten för framläggningen av avhandlingen var följande delarbete opublicerat: delarbete 3 (inskickat).

At the time of the defence the following paper was unpublished: paper 3 (submitted).

Tillgänglig från: 2019-12-04 Skapad: 2019-12-03 Senast uppdaterad: 2019-12-04Bibliografiskt granskad
2. Electron beam powder bed fusion processing of stainless steels
Öppna denna publikation i ny flik eller fönster >>Electron beam powder bed fusion processing of stainless steels
2023 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Additive manufacturing (AM) is still a relatively new technology. In contrast to traditional machining where material is removed from a blank, AM is used to fuse a feedstock material into complex shapes, layer by layer, starting from an empty workspace. AM enables the manufacture of complex part geometries and part variations with little to no extra manufacturing cost. Manufacturing of geometries which was not previously possible, are now available as design options such as bent internal channels, intricate lattice structures and designed surface porosity - all of which can be produced repeatably. Electron beam powder bed fusion (PBF-EB) is an AM method in which an electron beam is used to process a fine-grained powder into parts. Since its conception, PBF-EB has been hampered by the number of materials available for processing. The aim of this thesis is to explore the possibilities for processing stainless steels using PBF-EB. The work is focused on the development of parameters for efficient processing with the aim of achieving high-density as-built materials and an understanding of the relationship between process parameters and the resulting microstructure and other quality aspects of the parts. Two stainless steel powders, 316LN (austenitic) and super duplex 2507 (austenitic / ferritic), are processed via a wide range of process parameters into solid parts using various melting strategies. Density, microstructural features, and mechanical properties are evaluated and assessed before selecting a set of parameters that produce high-quality parts at a high processing rate. This work concludes that stainless steels are well suited for PBF-EB processing, with a wide processing window. The studies also show that the material properties are highly influenced by the processing parameters used. In the case of super duplex stainless steel 2507 the built parts require post-build heat treatment to achieve the desired microstructure, phase-composition and tensile properties, while 316LN can to a larger extent be used as-built, provided that proper build preparation and processing parameters are used.

Ort, förlag, år, upplaga, sidor
Östersund: Mid Sweden University, 2023. s. 85
Serie
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 396
Nyckelord
Additive manufacturing, Electron beam powder bed fusion, PBF-EB, Stainless steel, Mechanical properties, Micro-structure, Nanoindentation
Nationell ämneskategori
Maskinteknik
Identifikatorer
urn:nbn:se:miun:diva-49338 (URN)978-91-89786-31-8 (ISBN)
Disputation
2023-10-17, Q221, Akademigatan 1, 83140 Östersund, Östersund, 09:00 (Engelska)
Opponent
Handledare
Forskningsfinansiär
KK-stiftelsenInterreg
Anmärkning

Vid tidpunkten för disputationen var följande delarbeten opublicerade: delarbete 5 under granskning och delarbete 6 manuskript.

At the time of the doctoral defence the following papers were unpublished: paper 5 under review and paper 6 in manuscript.

Tillgänglig från: 2023-09-22 Skapad: 2023-09-19 Senast uppdaterad: 2023-09-19Bibliografiskt granskad

Open Access i DiVA

fulltext(2913 kB)863 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 2913 kBChecksumma SHA-512
398d81059059c2807b76cb5b79fc7952e990727b9ee87419e63c9607d4bdcf54b24177b7c57c63c760c0fe75ab9b193b80c51b8887133b30d5b3315565fa269e
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltextScopus

Person

Roos, StefanBotero Vega, Carlos AlbertoDanvind, JonasKoptioug, AndreiRännar, Lars-Erik

Sök vidare i DiVA

Av författaren/redaktören
Roos, StefanBotero Vega, Carlos AlbertoDanvind, JonasKoptioug, AndreiRännar, Lars-Erik
Av organisationen
Institutionen för kvalitets- och maskinteknik
I samma tidskrift
Journal of materials engineering and performance (Print)
Annan maskinteknikAnnan maskinteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 866 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 1308 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf