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Home  >  Journal list  >  Journal of the Ceramic Society of Japan  >  Vol.117  No.1367 (July) (2009)  >  pp.836-841

Journal of the Ceramic Society of Japan
<<Previous article Vol.117  No.1367 (July) (2009)   pp.836 - 841 Next article>>

Relation between functional properties of alumina-based nanocomposites and locations of dispersed particles

Yoshitaka NISHIMURA1)2), Kenichiro AIKAWA1), Seong-Min CHOI2), Shinobu HASHIMOTO1) and Yuji IWAMOTO1)
1) Nagoya Institute of Technology
2) Fuji Electric Device Technology

  We previously proposed the toughening and strengthening mechanisms of alumina-based nanocomposites on the basis of dislocation activities, assuming that nano-sized particles were embedded within the alumina grains. In this research, we fabricated both intragranular dominant and intergranular dominant nanocomposites of alumina/nickel(Ni) system. In order to fabricate intragranular dominant nanocomposites, γ-alumina powder with many nanopores was used as a starting material through a soaking method. Intergranular dominant nanocomposites were prepared using α-alumina powder as a starting material. Monolithic alumina samples were also sintered for comparison. Mechanical, thermal, and electrical properties were estimated for those specimens. The results showed that the intragranular nanocomposites had a higher mechanical strength and fracture toughness than the intergranular nanocomposites. The values of thermal expansion and thermal conductivity were slightly high in the intragranular nanocomposites compared to the intergranular one. The intergranular nanocomposites indicated a low dielectric breakdown voltage. Relations between the functional properties of the nanocomposites and the location of the dispersed Ni particles were discussed based on dislocation activities and the percolation model.

Nanocomposites, Alumina, Nickel, Thermal expansion, Thermal conductivity, Dielectric constant, Breakdown voltage

Received: March 16, 2009
Accepted: May 21, 2009 , Published online: July 01, 2009
Copyright (c) 2009 The Ceramic Society of Japan



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