Impedance changes and carbon stability during the heat treatment of Si 3N4 - carbon composites

B. Fényi, N. Hegman, K. Szemmelveisz, Csaba Balázsi

Research output: Contribution to journalArticle

Abstract

Electrical properties of the insulator silicon nitride ceramics may be improved by addition of electrical conductive parts. The conductive carbon parts were mixed with the base ceramic matrix to form a percolation network. Electrical current can flow through the ceramic by using the connected carbon channels. In air atmosphere however, the carbon can oxidize and burn out. Heat treatments were performed to observe the carbon degradation in composites in atmosphere. As resulted, the carbon exhaust started at 400°C from surface and finished above 750°C. Electrical measurements showed the conductor-insulator transformation. Thermogravimetric measurements suggested that some carbon inclusion still remained in isolated closed porosities.

Original languageEnglish
Pages (from-to)365-368
Number of pages4
JournalKey Engineering Materials
Volume409
DOIs
Publication statusPublished - Aug 18 2009

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Keywords

  • Carbon nanotube
  • Carbon stability
  • Impedance
  • Silicon nitride

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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