Fabrication of complex-shaped alumina/nickel nanocomposites by gelcasting process

Koichi Niihara, Bum Sung Kim, Tadachika Nakayama, Takafumi Kusunose, Takuya Nomoto, Akio Hikasa, Tohru Sekino

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)

Abstract

Complex-shaped Al2O3/Ni nanocomposites with preserved multifunctional magnetic properties are successfully fabricated by a gelcasting process. Based on an investigation of the effects of suspension composition on the drying, debinding, and reduction-pressureless sintering processes, a stable Al2O3/NiO binary oxide aqueous suspension with optimal monomer, dispersant, and solid composition is defined. Wet gelcast bodies produced using this suspension system shrink by 4.72% during humidity-controlled drying, with a bending strength of the fully dried green body of 3.84±0.84 MPa. The interconnected void structure of the debound green body provides hydrogen reduction of dispersed NiO without metamorphosis or shrinkage. Al2O3/Ni nanocomposites with complex shapes are successfully produced by pressureless sintering, and exhibit appropriate strength (586±50 MPa) after 21.5% shrinkage. Dispersed Ni particles exhibit typical ferromagnetic behavior in the Al2O3 matrix. This study confirms that gelcasting is a viable process for fabricating industrially applicable Al2O3/Ni nanocomposites with balanced mechanical and magnetic properties.

Original languageEnglish
Pages (from-to)3419-3425
Number of pages7
JournalJournal of the European Ceramic Society
Volume24
Issue number12
DOIs
Publication statusPublished - 2004 May 7

Keywords

  • AlO
  • Gelcasting
  • Nanocomposites
  • Ni
  • Suspensions

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

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