liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Attempts to use computerised tomography and image analysis to investigate the influence of the filling operation on the density of compressed rings
Linköping University, Department of Mechanical Engineering, Engineering Materials. Linköping University, The Institute of Technology.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Computerised tomography has the potential to become an invaluable tool for R&D activities within the field of powder metallurgy. At the present the method is however not sufficiently adapted for this application. Here a novel experimental routine combining computerised tomography with image analysis have been used to investigate the influence of the filling operation on the density distributions within compressed rings. Sufficient time was however not available to fully interpret the produced result and to validate the reliability of this technique. Analysis of less complex samples with known density distributions is suggested as a way to continue this investigation and to test the reliability of the method. The outline for a project where such a study could be perfom1ed is included in this report.

National Category
Engineering and Technology
URN: urn:nbn:se:liu:diva-102052OAI: diva2:668038
Available from: 2013-11-28 Created: 2013-11-28 Last updated: 2013-11-28
In thesis
1. Studies of density variations in iron powder caused by the filling operation
Open this publication in new window or tab >>Studies of density variations in iron powder caused by the filling operation
2001 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Detailed information about the density within a part produced by compression of a granular material is perhaps the most important piece of information you need if you are to predict its properties. Nearly all mechanical properties are strongly dependent on the density and the density of a very small region within the part can potentially be disastrous if it has a density level considerably lower then the rest of the part. Filling induced density variations is a problem that long has been overlooked by powder metallurgy scientists. One of the factors that are making investigations difficult is the lack of methods to make experimental data available. In this work four different methods for this purpose have been evaluated.

Metallographic examinations

Has proven to be a reliable method to provide information about the density variations in cut, 2 dimensional cross sections of PM samples. To produce the amount of data necessary to study the filling operation is however considered too labour intensive.

Bulk densitv measurements of compressed samples

A simple and reliable method, perfect for thorough investigations of densityvariations in industrially produced PM components.

Density measurements of filled powder

Although not as accurate as bulk density measurements the increased flexibility of this method can be an advantage when investigating filling behaviour. A novel test rig was constructed that was able to identify and link several different factors to the resulting density variations.

Computerised Tomography

This method has the potential to deliver the same information as metallographic examinations in a much faster and more reliable way. It has however not yet been established if the accuracy ofthe method is sufficient to provide information about the density variation in PM samples caused by the filling operation.

With the bulk density and the filled powder methods deeper studies were also performed to increase the knowledge of powder filling behaviour. It has been established that the filling operation causes density variations within PM parts and that these variations are highly systematic. With the construction of the test rig it was possible to determine several aspects of the feed shoe cycle as responsible for these variations.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2001. 18 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 905
National Category
Engineering and Technology
urn:nbn:se:liu:diva-30050 (URN)15510 (Local ID)91-7373-122-6 (ISBN)15510 (Archive number)15510 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2013-11-28

Open Access in DiVA

No full text

By organisation
Engineering MaterialsThe Institute of Technology
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 10 hits
ReferencesLink to record
Permanent link

Direct link