Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
On the effect of particle size distribution in cold powder compaction
KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).ORCID iD: 0000-0001-7674-8582
KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).ORCID iD: 0000-0001-6232-8819
2012 (English)In: Journal of applied mechanics, ISSN 0021-8936, E-ISSN 1528-9036, Vol. 79, no 5, 051017- p.Article in journal (Refereed) Published
Abstract [en]

The effect of particle size distribution in powder compaction has been studied using the discrete element method. Both isostatic compaction and closed die compaction are studied together during the entire loading process. Particle rotation and frictional effects are accounted for in the analysis. The particles are, constitutively described by rigid plasticity, assumed to be spherical with the size of the radii that follows a truncated normal distribution. The results show that size distribution effects are small on global compaction properties like compaction pressure if the size distribution is small. Furthermore, the size distribution had no influence at all on the macroscopic behavior at unloading. To verify the model, comparisons were made on two different sets of experiment found in the literature where the particles were of varying sizes. Good agreement was found both on fundamental properties like the average number of contacts per particle and on more important properties from a practical point of view, like the compaction pressure.

Place, publisher, year, edition, pages
2012. Vol. 79, no 5, 051017- p.
Keyword [en]
Discrete element method, Particle size distribution, Powder compaction
National Category
Applied Mechanics
Identifiers
URN: urn:nbn:se:kth:diva-83869DOI: 10.1115/1.4006382ISI: 000308413800017Scopus ID: 2-s2.0-84865126805OAI: oai:DiVA.org:kth-83869DiVA: diva2:499054
Funder
Vinnova
Note

QC 20120913

Available from: 2012-02-13 Created: 2012-02-13 Last updated: 2017-12-07Bibliographically approved
In thesis
1. Micromechanics of Powder Compaction and Particle Contact
Open this publication in new window or tab >>Micromechanics of Powder Compaction and Particle Contact
2013 (English)Licentiate thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. viii, 8 p.
Series
Trita-HFL. Report / Royal Institute of Technology, Solid Mechanics, ISSN 1654-1472 ; 0534
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-117608 (URN)978-91-7501-643-4 (ISBN)
Presentation
2013-02-22, Hållfasthetsläras seminarierum, Teknikringen 8, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20130201

Available from: 2013-02-01 Created: 2013-01-31 Last updated: 2013-02-01Bibliographically approved
2. Micromechanics of Powder Compaction
Open this publication in new window or tab >>Micromechanics of Powder Compaction
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Compaction of powders followed by sintering is a convenient manufacturing method for products of complex shape and components of materials that are difficult to produce using conventional metallurgy. During the compaction and the handling of the unsintered compact, defects can develop which could remain in the final sintered product. Modeling is an option to predict these issues and in this thesis micromechanical modeling of the compaction and the final components is discussed. Such models provide a more physical description than a macroscopic model, and specifically, the Discrete Element Method (DEM) is utilized.

An initial study of the efect of particle size distribution, performed with DEM, was presented in Paper A. The study showed that this effect is small and is thus neglected in the other DEM studies in this thesis. The study also showed that good agreement with experimental data can be obtained if friction effects is correctly accounted for.

The most critical issue for accurate results in the DEM simulations is the modeling of normal contact between the powder particles. A unified treatment of this problem for particles of a strain hardening elastic-plastic material is presented in Paper B. Results concerning both the elastic-plastic loading, elastic unloading as well as the adhesive bonding between the particles is included. All results are compared with finite element simulation with good agreement with the proposed model.

The modeling of industry relevant powders, namely spray dried granules is presented in Paper C. The mechanical behavior of the granules is determined using two types of micromechanical experiments, granule compression tests and nanoindentation testing. The determined material model is used in an FEM simulation of two granules in contact. The resulting force-displacement relationships are exported to a DEM analysis of the compaction of the granules which shows very good agreement with corresponding experimental data.

The modeling of the tangential forces between two contacting powder particles is studied in Paper D by an extensive parametric study using the finite element method. The outcome are correlated using normalized parameters and the resulting equations provide the tangential contact force as function of the tangential displacement for different materials and friction coefficients.

Finally, in Paper E, the unloading and fracture of powder compacts, made of the same granules as in Paper C, are studied both experimentally and numerically. A microscopy study showed that fracture of the powder granules might be of importance for the fracture and thus a granule fracture model is presented and implemented in the numerical model. The simulations show that incorporating the fracture of the granules is essential to obtain agreement with the experimental data.

 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. viii, 22 p.
Series
TRITA-HLF, ISSN 1104-6813 ; 0565
National Category
Engineering and Technology
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:kth:diva-159142 (URN)978-91-7595-430-1 (ISBN)
Public defence
2015-02-13, Sal F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20150122

Available from: 2015-01-22 Created: 2015-01-22 Last updated: 2015-01-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Olsson, ErikLarsson, Per-Lennart

Search in DiVA

By author/editor
Olsson, ErikLarsson, Per-Lennart
By organisation
Solid Mechanics (Div.)
In the same journal
Journal of applied mechanics
Applied Mechanics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 156 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf