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Densification of electrically conductive composites close to percolation threshold

Verdichtung elektrisch leitfähiger Composite nahe der Perkolationsschwelle
 
: Räthel, J.; Herrmann, M.; Beckert, W.; Nürnberger, M.

:
Fulltext urn:nbn:de:0011-n-1062492 (355 KByte PDF)
MD5 Fingerprint: 3b94bc0858b60a3250962258d683d2c0
Created on: 8.10.2009


Max-Planck-Institut für Chemische Physik fester Stoffe; Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung -IFAM-, Dresden:
APNFM 2008, Advanced processing for novel functional materials : 23-25 January 2008, International Congress Center Dresden, Germany
Dresden, 2008
pp.18-21
International Conference Advanced Processing of Novel Functional Materials (APNFM) <2008, Dresden>
English
Conference Paper, Electronic Publication
Fraunhofer IKTS ()
field assisted sintering technology; spark plasma sintering; FAST; SPS; Titanium-Diboride; boron nitride; TiB2; BN; temperature distribution; percolation

Abstract
The densification behaviour of hexagonal BN/TiB2 composites by Field Assisted Sintering Technology (FAST)/ Spark Plasma Sintering (SPS) was investigated. The investigations were carried out using shrinkage curves, mircrostructure evaluations and FE modeling. Additionally, in-situ measurements of the temperature were taken at two positions using an internal and external control pyrometer. hBN/TiB2 composite materials with a composition close to the percolation threshold show a complex sintering behaviour. They become conductive in a large range of temperature, starting at 1,300°C. An Ostwald ripening process of the
TiB2 grains cause the microstructural development at a comparatively long dwell time. So, homogeneous distributions in resistivity were obtained with a dwell time of 30 min. In comparison to traditional hot pressing processes the overall cycle time can be reduced.

: http://publica.fraunhofer.de/documents/N-106249.html