Investigation of temperature approximation methods during flash sintering of ZnO

Harry Charalambous, Shikhar Krishn Jha, Ryan T. Lay, Avaniek Cabales, John Okasinski, Thomas Tsakalakos

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

The lattice expansion in ZnO, using in-situ X ray diffraction, has been investigated during flash sintering with varying current densities. While current flow through the specimen enhances the kinetics of sintering for ZnO, the temperature is not high enough to claim thermal runaway or localized melting. Unlike the case of yttria stabilized zirconia [1,2], experimental temperature approximations predict comparable specimen temperature to conventional sintering temperature of ZnO. Microstructural analysis supports the findings of the in-situ temperature approximations. In comparison with black body radiation, a gap between theoretical value and measured value was found due to flaws in the theoretical model. In addition, a new type of flash sintering was introduced, with current ramp, to avoid the power spike which has been the source of much debate about the transition from voltage to current control. The advantage of this method is in the controlled sintering kinetics thus avoiding the channeling found in dielectric materials [3].

Original languageEnglish (US)
Pages (from-to)6162-6169
Number of pages8
JournalCeramics International
Volume44
Issue number6
DOIs
Publication statusPublished - Apr 15 2018

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Materials Chemistry

Keywords

  • Blackbody radiation
  • Flash
  • In situ diffraction
  • Sintering
  • Zinc oxide
  • Zno

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