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Journal of Materials Science

, Volume 29, Issue 4, pp 1097–1100 | Cite as

Positive temperature coefficient of resistance effect in hot-pressed cristobalite-silicon carbide composites

  • Du Wei-Fang
  • Tan Xu
  • Du Hai-Qing
Papers

Abstract

Conductive silicon carbide particles were incorporated into an insulating cristobalite ceramic matrix to produce composite materials with a sizeable positive temperature coefficient (PTC) effect. A large drop in resistivity with silicon carbide content at room temperature, or percolation behaviour, was observed. The PTC effect of the composites, which resulted from the thermal expansion of the cristobalite ceramic matrix, was a maximum with five orders of magnitude for the specimen with 25 vol% silicon carbide. The PTC transition temperature of the composites was at 260 °C, which coincided exactly the reversible high-low phase inversion temperature of the cristobalite ceramic matrix.

Keywords

Carbide Thermal Expansion Composite Material Material Processing Silicon Carbide 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • Du Wei-Fang
    • 1
  • Tan Xu
    • 1
  • Du Hai-Qing
    • 1
  1. 1.Institute of Materials Science and Application ChemistryUniversity of HunanChangShaPeople’s Republic of China

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