Tensile stress evolution during the early-stage constrained sintering of Gadolinium-doped ceria films

Brian W. Sheldon, Jason D. Nicholas, Sunil Mandowara

Research output: Contribution to journalArticle

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Abstract

In situ measurements during the constrained sintering of Gd-doped ceria reveal tensile stresses up to ∼250 MPa. These large tensile stresses are likely to contribute to the reduced densification (compared with freely sintered material) typically observed during constrained sintering. While existing models postulate that the tensile stress in a densifying constrained film cannot exceed the "sintering stress,"sigma;S, the observed tensile stresses are significantly larger than the estimated sigma;S for these materials. To explain this observation, we propose that the formation and extension of interparticle grain boundaries induce substantial tensile stresses in constrained films. A model of this phenomenon shows that converting excess surface energy to elastic strain energy can produce stresses that are comparable to the measured values. Further, if these "cohesive" stresses exceed sigma;S, grain-boundary diffusion should initially move material from the neck regions into the grain boundaries, not out of the grain boundaries as described by traditional sintering models.

LanguageEnglish (US)
Pages209-216
Number of pages8
JournalJournal of the American Ceramic Society
Volume94
Issue number1
DOIs
StatePublished - Jan 2011

Profile

gadolinium
Gadolinium
tensile stress
Cerium compounds
Tensile stress
grain boundary
Sintering
Grain boundaries
surface energy
Strain energy
Densification
Interfacial energy
in situ measurement
sintering
energy
material

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

Cite this

Tensile stress evolution during the early-stage constrained sintering of Gadolinium-doped ceria films. / Sheldon, Brian W.; Nicholas, Jason D.; Mandowara, Sunil.

In: Journal of the American Ceramic Society, Vol. 94, No. 1, 01.2011, p. 209-216.

Research output: Contribution to journalArticle

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