Flash sintering scaling-up challenges: Influence of the sample size on the microstructure and onset temperature of the flash event

2020 ◽  
Vol 186 ◽  
pp. 1-5
Author(s):  
João V. Campos ◽  
Isabela R. Lavagnini ◽  
João G. Pereira da Silva ◽  
Julieta A. Ferreira ◽  
Rafael V. Sousa ◽  
...  
Keyword(s):  
Sample Size ◽  
Scaling Up ◽  
Onset Temperature ◽  
Flash Sintering ◽  
Flash Event

scholarly journals Gd/Sm-Pr Co-Doped Ceria: A First Report of the Precipitation Method Effect on Flash Sintering

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1218 ◽  
Author(s):  
Luca Spiridigliozzi ◽  
Lorenzo Pinter ◽  
Mattia Biesuz ◽  
Gianfranco Dell’Agli ◽  
Grazia Accardo ◽  
...  
Keyword(s):  
Ammonia Solution ◽  
Current Control ◽  
Precipitation Method ◽  
Precipitation Process ◽  
Sintering Behavior ◽  
Method Effect ◽  
Flash Sintering ◽  
Co Precipitation ◽  
First Time ◽  
Flash Event

In this work, ceria-based ceramics with the composition Gd0.14Pr0.06Ce0.8O2-δ and Sm0.14Pr0.06Ce0.8O2-δ, were synthesized by a simple co-precipitation process using either ammonium carbonate or ammonia solution as a precipitating agent. After the calcination, all of the produced samples were constituted by fluorite-structured ceria only, thus showing that both dopant and co-dopant cations were dissolved in the fluorite lattice. The ceria-based nanopowders were uniaxially compacted and consequently flash-sintered using different electrical cycles (including current-ramps). Different results were obtained as a function of both the adopted precipitating agent and the applied electrical cycle. In particular, highly densified products were obtained using current-ramps instead of “traditional” flash treatments (with the power source switching from voltage to current control at the flash event). Moreover, the powders that were synthesized using ammonia solution exhibited a low tendency to hotspot formation, whereas the materials obtained using carbonates as the precipitating agent were highly inhomogeneous. This points out for the first time the unexpected relevance of the precipitating agent (and of the powder shape/degree of agglomeration) for the flash sintering behavior.

Graphite assisted flash sintering of Sm2O3 doped CeO2 ceramics at the onset temperature of 25 °C

2019 ◽  
Vol 159 ◽  
pp. 72-75 ◽  
Author(s):  
Lili Guan ◽  
Jian Li ◽  
Xiwen Song ◽  
Jinxiao Bao ◽  
Tao Jiang
Keyword(s):  
Onset Temperature ◽  
Flash Sintering ◽  
Doped Ceo2

scholarly journals Liquid-Film Assisted Mechanism of Reactive Flash Sintering in Oxide Systems

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1494 ◽  
Author(s):  
Rachman Chaim ◽  
Yaron Amouyal
Keyword(s):  
Liquid Film ◽  
Binary Systems ◽  
Solid Phase ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Onset Temperature ◽  
Phase Assemblage ◽  
Reaction Products ◽  
Oxide Systems ◽  
Flash Sintering

Reactive flash sintering in oxide systems is analyzed assuming the formation of a liquid film at the particle contacts at the flash onset temperature. Formation of intermediate phases, as well as phase assemblage, are predicted upon optimal conditions of the electric field and current density. In single-phase impure oxides, the solidus and the solubility limit determine the flash onset temperature. In reacting binary systems, the composition of the liquidus determines primarily the reaction products during the cooling. In multicomponent systems, the oxide with the lowest flash temperature forms the interfacial liquid film, and the solid phase assemblage follows the equilibrium phase diagram. Examples from literature are consistent with reactive flash sintering and flash sintering assisted by a transient liquid film.

scholarly journals Effect of Processing Conditions on the Flash Onset Temperature in Hydroxyapatite

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5229
Author(s):  
Changhun Hwang ◽  
Jondo Yun
Keyword(s):  
Grain Size ◽  
Electric Field ◽  
Color Change ◽  
Onset Temperature ◽  
Processing Conditions ◽  
Conduction Path ◽  
Flash Sintering ◽  
Vacuum Atmosphere ◽  
Lower Temperature ◽  
Short Time

When heat and electric field are applied to the sample, sintering takes place within a short time of a few seconds by the flash phenomenon that occurs. In what condition flash does occur is a main issue for the flash sintering technique. In this study, the effect of processing conditions such as sintering atmosphere, sample size, density and grain size on the flash onset of hydroxyapatite was investigated. In a vacuum atmosphere, a flash occurred at a lower temperature by 50–100 °C than in air. The smaller the thickness of the sample, the higher the flash onset temperature due to the larger specific surface area. Flash was also observed in samples which were presintered, having a density of 86–100% and a grain size of 0.2–0.9 μm. When the density and grain size of the sample were higher and larger, the flash onset temperature was higher. It was because the diffusion and conduction path through the grain boundary and the inner surface of the pores with high defect concentration are blocked with an increase of density or grain size. When an electric field was applied during flash sintering, a color change of the sample was observed and the reason was discussed.

Sample Size and the Detection of Correlation--A Signal Detection Account: Comment on Kareev (2000) and Juslin and Olsson (2005).

2005 ◽  
Vol 112 (1) ◽  
pp. 268-279 ◽  
Author(s):  
Richard B. Anderson ◽  
Michael E. Doherty ◽  
Neil D. Berg ◽  
Jeff C. Friedrich
Keyword(s):  
Signal Detection ◽  
Sample Size

ANTI-V task: Sample size can be fitted to task assessment requirements?

2011 ◽  
Author(s):  
M. Lopez-Ramon ◽  
C. Castro ◽  
J. Roca ◽  
J. Lupianez
Keyword(s):  
Sample Size ◽  
Task Assessment ◽  
Assessment Requirements
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