Electroluminescence and the measurement of temperature during Stage III of flash sintering experiments

Terauds, Kalvis; Lebrun, Jean‐Marie; Lee, Hyun-Hwi; Jeon, Tae‐Yeol; Lee, Sang-Hyeon; Je, Jung Ho; Raj, Rishi

doi:10.1016/j.jeurceramsoc.2015.03.040

Cited by 121 publications

(117 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The heterogeneity in grain size between core and curved surface observed in the microstructure of samples FS 100 , FS 200 , can be explained by their cylindrical shape associated with their heating rates. Cylindrical samples usually have a smaller surface‐area‐to‐volume ratio than dog‐bone‐shaped samples . Samples with a lower surface‐area‐to‐volume ratio retain more thermal energy in the core region than at the surface owing to their heating loss mechanisms .…”

Section: Resultsmentioning

confidence: 99%

Microstructural evolution of 3YSZ flash‐sintered with current ramp control

et al. 2020

View full text Add to dashboard Cite

The effect of a controlled current ramp during flash sintering (FS) on the densification and microstructural evolution of 3 mol% yttria‐stabilized zirconia was investigated. The samples were flash sintered using a current ramp control with six different current ramp rates and compared with samples sintered by FS without current ramp control. In both cases, maximum electric current densities of 100 and 200 mA mm−2 were used. The microstructure of cylindrical samples was observed, showing grain size heterogeneity between the curved surface and the core for the flash‐sintered (FSed) samples regardless of the maximum current density used. By contrast, the current ramp FSed samples exhibited a homogeneous grain size when the electric current density of 100 mA mm−2 was applied. Thus, controlling a current ramp during FS can be an alternative for avoiding grain size heterogeneity on ceramics sintered by this technique.

show abstract

Section: Resultsmentioning

confidence: 99%

Microstructural evolution of 3YSZ flash‐sintered with current ramp control

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The set-up used for in situ XRD during FS is shown in Figure 8 [40,71]. It is worth noting that any reversible material structural transformation, which might occur when the field is turned off and the material is cooled down to room temperature, might not be captured without in situ techniques.…”

Section: Phase Analysismentioning

confidence: 99%

Review of flash sintering: materials, mechanisms and modelling

Grasso

McKinnon

et al. 2016

Advances in Applied Ceramics

401

248

View full text Add to dashboard Cite

Flash sintering (FS) is an energy efficient sintering technique involving electrical Joule heating, which allows very rapid densification (<60 s) of particulate materials. Since the first publication on flash-sintered zirconia (3YSZ) in 2010, it has been intensively researched and applied to a wide range of materials. Going back more than a century ago, we have found a close similarity between FS of oxides and Nernst glowers developed in 1897. This review provides a comprehensive overview of FS and is based on a literature survey consisting of 88 papers and seven patents. It correlates processing parameters (i.e. electric field magnitude, current density, waveforms (AC, DC) and frequency, furnace temperature, electrode materials/ configuration, externally applied pressure and sintering atmosphere) with microstructures and densification mechanisms. Theorised mechanisms driving the rapid densification are substantiated by modelling work, advanced in situ analysis techniques and by established theories applied to electric current assisted/activated sintering techniques. The possibility of applying FS to a wider range of materials and its implementation in industrial scale processes are discussed.

show abstract

“…In addition it has been established using measurements of the optical spectrum of the emission that the glowing of the samples during flash sintering is due to electroluminescence, rather than black body radiation [34,123]. The collective findings of these experiments [34,39,123] have led to the acknowledgement of the importance of current and sample conductivity in the flash sintering process in more recent papers.…”

Section: Experimentally-derived Observations Of the Regimes Of Flash mentioning

confidence: 99%

Flash sintering of ceramic materials

Dancer¹

2016

Mater. Res. Express

159

View full text Add to dashboard Cite

During flash sintering, ceramic materials can sinter to high density in a matter of seconds while subjected to electric field and elevated temperature. This process, which occurs at lower furnace temperatures and in shorter times than both conventional ceramic sintering and field-assisted methods such as spark plasma sintering, has the potential to radically reduce the power consumption required for the densification of ceramic materials. This paper reviews the experimental work on flash sintering methods carried out to date, and compares the properties of the materials obtained to those produced by conventional sintering. The flash sintering process is described for oxides of zirconium, yttrium, aluminium, tin, zinc, and titanium; silicon and boron carbide, zirconium diboride, materials for solid oxide fuel applications, ferroelectric materials, and composite materials. While experimental observations have been made on a wide range of materials, understanding of the underlying mechanisms responsible for the onset and latter stages of flash sintering is still elusive. Elements of the proposed theories to explain the observed behaviour include extensive Joule heating throughout the material causing thermal runaway, arrested by the current limitation in the power supply, and the formation of defect avalanches which rapidly and dramatically increase the sample conductivity.Undoubtedly, the flash sintering process is affected by the electric field strength, furnace temperature and current density limit, but also by microstructural features such as the presence of second phase particles or dopants and the particle size in the starting material. While further experimental work and modelling is still required to attain a full understanding capable of predicting the success of the flash sintering process in different materials, the technique nonetheless holds great potential for exceptional control of the ceramic sintering process.

show abstract

Electroluminescence and the measurement of temperature during Stage III of flash sintering experiments

Cited by 121 publications

References 9 publications

Microstructural evolution of 3YSZ flash‐sintered with current ramp control

Microstructural evolution of 3YSZ flash‐sintered with current ramp control

Review of flash sintering: materials, mechanisms and modelling

Flash sintering of ceramic materials

Contact Info

Product

Resources

About