Grain growth in sinered ZnO and ZnO-Bi sub 2 O sub 3 ceramics

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1990.tb05099.x· OSTI ID:6786172

Senda, T ^[1]; Bradt, ^[2]

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1. Ship Research Inst., Tokyo (Japan)
2. Nevada Univ., Las Vegas, NV (USA). Mackay School of Mines

Grain growth in a high-purity ZnO and for the same ZnO with Bi{sub 2}O{sub 3} additions from 0.5 to 4 wt% was studied for sintering from 900{degrees} to 1400{degrees}C in air. The results are discussed and compared with previous studies in terms of the phenomenological kinetic grain growth expression: G{sup n} {minus} G{sup n}{sub 0} = K{sub 0}t exp({minus} Q/RT). For the pure ZnO, the grain growth exponent or n value was observed to be 3 while the apparent activation energy was 224 {plus minus}16 kJ/mol. These parameters substantiate the Gupta and Coble conclusion of a Zn{sub 2 +} lattice diffusion mechanism. Additions of Bi{sub 2}O{sub 3} to promote liquid-phase sintering increased the ZnO grain size and the grain growth exponent to about 5, but reduced the apparent activation energy to about 150 kJ/mol, independent of Bi{sub 2}O{sub 3} content. The preexponential term K{sub 0} was also independent of Bi{sub 2}O{sub 3} content. It is concluded that the grain growth of ZnO in liquid-phase- sintered ZnO-Bi{sub 2}O{sub 3} ceramics is controlled by the phase boundary reaction of the solid ZnO grains and the Bi{sub 2}O{sub 3}-rich liquid phase.

• OSTI ID: 6786172
• Journal Information: Journal of the American Ceramic Society; (USA), Journal Name: Journal of the American Ceramic Society; (USA) Vol. 73:1; ISSN JACTA; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ACTIVATION ENERGY
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
CRYSTAL STRUCTURE
DIFFUSION
ENERGY
EPITAXY
FABRICATION
GRAIN ORIENTATION
LATTICE PARAMETERS
LIQUID PHASE EPITAXY
MICROSTRUCTURE
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
SINTERING
VERY HIGH TEMPERATURE
ZINC COMPOUNDS
ZINC OXIDES