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Indian Journal of Engineering and Materials Sciences (IJEMS) >
IJEMS Vol.16 [2009] >
IJEMS Vol.16(4) [August 2009] >
| Title: | Nanostructured silver-graphite electrical contact materials processed by mechanical milling |
| Authors: | Rehani, Bharati R
Joshi, P B
Kaushik, V K |
| Keywords: | Silver-graphite contact materials
High-energy milling
Nanocomposite powders
Powder metallurgy process |
| Issue Date: | Aug-2009 |
| Publisher: | CSIR |
| Abstract: | In last few decades there has been a growing interest in
nanostructured materials in view of their improved mechanical, physical and
chemical properties. A wide variety of techniques have been developed to
synthesize nanopowders including high-energy milling or mechanical alloying
(MA) for producing bulk nanostructures. High-energy milling is used for
preparation of elemental and composite powders of different metals and
non-metals. Literature reports the synthesis of ductile-ductile composites such
as aluminium-graphite and copper-graphite by MA owing to its potential benefits
in terms of improved mechanical properties. Reports are also there on the application
of this technology for processing of silver-graphite contact materials offering
improved switching properties.
The
present investigation deals with a comparative study on synthesis of silver-graphite nanocomposite
powders in a planetary ball mill using two different approaches, namely milling
of a blend of silver and graphite powder particles in one case and milling of
only elemental silver powder in the other. The study revealed that somewhat
inferior properties are obtained for the AgC bulk solids prepared from powders
synthesized by the former approach. This is in view of the tendency of graphite
to coat silver during milling, leading to very poor silver-silver interparticle
contacts and resultant bulk solid with high porosity. However, an alternative
approach of milling silver alone in the planetary mill is found to offer not
only improved properties but also reduction in sintering temperature. |
| Page(s): | 281-287 |
| ISSN: | 0975-1017 (Online); 0971-4588 (Print) |
| Source: | IJEMS Vol.16(4) [August 2009]
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