Current understanding and applications of the cold sintering process

Abstract In traditional ceramic processing techniques, high sintering temperature is necessary to achieve fully dense microstructures. But it can cause various problems including warpage, overfiring, element evaporation, and polymorphic transformation. To overcome these drawbacks, a novel processing technique called “cold sintering process (CSP)” has been explored by Randall et al. CSP enables densification of ceramics at ultra-low temperature (⩽300°C) with the assistance of transient aqueous solution and applied pressure. In CSP, the processing conditions including aqueous solution, pressure, temperature, and sintering duration play critical roles in the densification and properties of ceramics, which will be reviewed. The review will also include the applications of CSP in solid-state rechargeable batteries. Finally, the perspectives about CSP is proposed.

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Sintering densification curve: A practical approach for its construction from dilatometric shrinkage data

Science of Sintering ◽

10.2298/sos0802117m ◽

2008 ◽

Vol 40 (2) ◽

pp. 117-122 ◽

Cited By ~ 32

Author(s):

K. Maca ◽

V. Pouchly ◽

A.R. Boccaccini

Keyword(s):

High Temperature ◽

Sintering Temperature ◽

Practical Method ◽

Practical Approach ◽

Powder Technology ◽

Ceramic Processing ◽

Sintering Process ◽

Densification Curve ◽

Sample Density ◽

Sintering Shrinkage

This article summarizes the usage of high-temperature dilatometry in ceramic processing and powder technology with special attention on the description of the sintering process. A practical method for transformation of dilatometric shrinkage data into densification curves (the dependence of the sample density on sintering temperature or time) is described in detail. A new automatic procedure to recalculate sintering shrinkage data allowing the plot of the densification curve has been developed, which is presented here.

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Spatial Enhancement of AWiFS along Wider Swath using NSCT

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i3.12.16162 ◽

2018 ◽

Vol 7 (3.12) ◽

pp. 474

Author(s):

K S. R. Radhika ◽

C V. Rao ◽

V Kamakshi Prasad

Keyword(s):

Temporal Resolution ◽

Accuracy Assessment ◽

Super Resolution ◽

Computation Time ◽

Processing Technique ◽

Sensor Data ◽

Liss Iii ◽

Novel Processing ◽

Single Image Super Resolution ◽

Processing Techniques

Image acquisition in a wider swath, cannot assess the best spatial resolution (SR) and temporal resolution (TR) simultaneously, due to inherent limitations of space borne sensors. But any of the information extraction from remote sensed (RS) images demands the above characteristics. As this is not possible onboard, suitable ground processing techniques need to be evolved to realise the requirements through advanced image processing techniques. The proposed work deals with processing of two onboard sensor data viz., Resourcesat-1 (RS1): LISS-III, which has medium swath combined with AWiFS, which has wider swath data to provide high spatial and temporal resolution at the same instant. LISS-III at 23m and 24 days, AWiFS at 56m and 5 days spatial and temporal revisits acquire the data at different swaths. In the process of acquisition at the same time, the 140km swath of LISS-III coincides at the exact centre line 740km swath of AWiFS. If the non-overlapping area of AWiFS has same features of earth’s surface as of LISS-III overlapping area, it then provides a way to increase the SR of AWiFS to SR of LISS-III in the same non-overlapping area. Using this knowledge, a novel processing technique Fast One Pair Learning and Prediction (FOPLP) is developed in which time is optimized against the existing methods. FOPLP improves the SR of LISS-III in non-overlapping area using technique Single Image Super Resolution (SISR) with Non Sub sampled Contourlet Transforms (NSCT) method and is applied on different sets of images. The proposed technique resulting into an image having TR of 5 days, 740km swath at SR of 23m. Results have shown the strength of the proposed method in terms of computation time and prediction accuracy assessment.

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Synthesis and Structural Investigations of Ag-Added Ba-CuO Mixed Oxide for Gas Sensing

International Journal of Chemical Engineering ◽

10.1155/2011/592075 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Ahmed Mohamed El-Sayed ◽

Fathy Mohamed Ismail ◽

Saad Mabrouk Yakout

Keyword(s):

Solid State ◽

Gas Sensing ◽

Sintering Temperature ◽

Structure Characterization ◽

Ceramic Processing ◽

Sintering Process ◽

Structural Investigations ◽

X Ray ◽

State Ceramic ◽

Infrared Absorption Spectra

Compositions having the general formula BaTiO3- wt% Ag, where , and 2 have been prepared by solid state ceramic processing and sintered at 500 and for 5 h. Thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), infrared absorption spectra (IR), and scanning electron microscopy (SEM) were used to characterize the obtained sensor pellets. It was found that no solid state reaction took place between BaTiO3and CuO during sintering process. The sensitivity of the prepared sensors to CO2gas increases with increasing sintering temperature and Ag content. The correlation between Ag content at different sintering temperature and structure characterization is discussed.

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Study on Influencing Factors of Mechanical Properties of Ti(C,N)-Based Cermets

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.589-590.578 ◽

2013 ◽

Vol 589-590 ◽

pp. 578-583 ◽

Cited By ~ 2

Author(s):

Ya Cong Chai ◽

Han Lian Liu ◽

Chuan Zhen Huang ◽

Bin Zou ◽

Hua He Liu

Keyword(s):

Mechanical Properties ◽

Energy Dispersive Spectrometry ◽

Sintering Temperature ◽

Processing Technique ◽

Liquid Phase Sintering ◽

Binder Content ◽

Powder Size ◽

Initial Powder ◽

Sintering Process ◽

Higher Temperature

Ti(C,N)-based cermets were fabricated by the vacuum hot-processing technique. The effect of sintering process, initial powder size and binder content on mechanical properties of Ti(C,N)-based cermets were investigated. The composite was analyzed by the observation of scanning electron microscope (SEM) and energy dispersive spectrometry (EDS). The results showed that a lower sintering temperature led to insufficient liquid-phase sintering process, which reduced the density of the composite. However, higher temperature and longer holding time resulted in abnormal grain growth, which was not good for improving the mechanical properties of the composite. With the refinement of the initial powder size of the Ti(C,N), the fracture toughness reduced slightly, the flexural strength and Vickers hardness increased. The better mechanical properties were obtained when the binder content of the cermets was designed based on the eutectic composition of Mo-Ni binary alloy phase diagram.

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Effect of High Pressure Spark Plasma Sintering on the Densification of a Nb-Doped TiO2 Nanopowder

Ceramics ◽

10.3390/ceramics3040041 ◽

2020 ◽

Vol 3 (4) ◽

pp. 507-520

Author(s):

Alexandre Verchère ◽

Sandrine Cottrino ◽

Gilbert Fantozzi ◽

Shashank Mishra ◽

Thomas Gaudisson ◽

...

Keyword(s):

Phase Transition ◽

High Pressure ◽

Spark Plasma Sintering ◽

Sintering Temperature ◽

Applied Pressure ◽

Sintering Process ◽

Fine Grained ◽

Plasma Sintering ◽

Spark Plasma ◽

Lower Temperature

Sintering under pressure by means of the spark plasma sintering (SPS) technique is a common route to reduce the sintering temperature and to achieve ceramics with a fine-grained microstructure. In this work, high-density bulk TiO2 was sintered by high pressure SPS. It is shown that by applying high pressure during the SPS process (76 to 400 MPa), densification and phase transition start at lower temperature and are accelerated. Thus, it is possible to dissociate the two densification steps (anatase then rutile) and the transition phase during the sintering cycle. Regardless of the applied pressure, grain growth occurs during the final stage of the sintering process. However, twinning of the grains induced by the phase transition is enhanced under high pressure resulting in a reduction in the crystallite size.

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Preliminary Study on the Fabrication of Particulate Fuel through Pressureless Sintering Process

Science and Technology of Nuclear Installations ◽

10.1155/2016/3717361 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Jong-Hwan Kim ◽

Jung-Won Lee ◽

Ki-Hwan Kim ◽

Chan-Bock Lee

Keyword(s):

Powder Processing ◽

Sintering Temperature ◽

Spherical Particles ◽

Pressureless Sintering ◽

Sintering Process ◽

Pore Characteristics ◽

Centrifugal Atomization ◽

Preliminary Study ◽

Processing Techniques

U-10wt%Zr spherical particles for use as particulate fuel were prepared by centrifugal atomization and subjected to pressureless sintering, which is one of the simplest powder processing techniques. At sintering temperature of 1100°C for 30 or 60 min, all samples ranging from +50 to −325 mesh showed no apparent bonding between the particles. However, at 1150°C (80 min), all samples formed a bulk body and the microstructures showed apparent sintering stages. Particularly, sample B (50–70 mesh) and sample C (70–100 mesh) showed pore characteristics suitable for a particulate fuel. The results suggest that pressureless sinterability for U-10Zr particulate fuel can be improved by adding small-size (–325 mesh) particles.

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DENSIFICATION AND MECHANICAL PROPERTIES OF FeMn13-TiC COMPOSITE FABRICATED BY PULSED ELECTRIC CURRENT SINTERING PROCESS

Acta Metallurgica Slovaca ◽

10.12776/ams.v24i4.1195 ◽

2018 ◽

Vol 24 (4) ◽

pp. 273 ◽

Cited By ~ 1

Author(s):

Khanh Quoc Dang ◽

Quang Anh Hoang ◽

Hiep Van Tran ◽

Minh Cong Nguyen ◽

Hao Van Pham ◽

...

Keyword(s):

Mechanical Properties ◽

Relative Density ◽

Electric Current ◽

Sintering Temperature ◽

Applied Pressure ◽

Sintering Process ◽

X Ray Diffraction ◽

X Ray ◽

Pulsed Electric Current ◽

Different Temperatures

In the present work, FeMn13-40 wt.% TiC composite was fabricated by Pulsed Electric Current Sintering (PECS) process at different temperatures between 990 and 1020<sup>o</sup>C under a pressure of 60 MPa with a holding time of 5 min in the vacuum. Phases identification was done using the X-ray diffraction. The relative density, microstructure and hardness of the samples were characterized. The results showed that the relative density of FeMn13-TiC composite increased with the increase of sintering temperature. The highest relative density (96.19%) and the hardness (70.54 HRC) of the sample were achieved by PECS process, namely sintering at the temperature of 1020<sup>o</sup>C under the applied pressure of 60 MPa for 5 min.

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Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

Magnetochemistry ◽

10.3390/magnetochemistry7050056 ◽

2021 ◽

Vol 7 (5) ◽

pp. 56

Author(s):

Yimin Yang ◽

Xiaoying Li ◽

Ziyu Liu ◽

Dianjun Hu ◽

Xin Liu ◽

...

Keyword(s):

High Temperature ◽

Calcination Temperature ◽

Sintering Temperature ◽

Raw Materials ◽

Secondary Phase ◽

Coprecipitation Method ◽

Pressureless Sintering ◽

Densification Behavior ◽

Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

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Microwave Sintering and Microwave Dielectric Properties of (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 Ceramics

Materials ◽

10.3390/ma14020438 ◽

2021 ◽

Vol 14 (2) ◽

pp. 438

Author(s):

Shuwei Yang ◽

Bingliang Liang ◽

Changhong Liu ◽

Jin Liu ◽

Caisheng Fang ◽

...

Keyword(s):

Dielectric Properties ◽

Mobile Communications ◽

Sintering Temperature ◽

Microwave Sintering ◽

Microwave Dielectric Properties ◽

Conventional Heating ◽

Sintering Process ◽

Microwave Dielectric ◽

Sintering Time ◽

Frequency Temperature

The (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 [(1–x)CLT-xNMT, x = 0.35~0.60] ceramics were prepared via microwave sintering. The effects of sintering temperature and composition on the phase formation, microstructure, and microwave dielectric properties were investigated. The results show that the microwave sintering process requires a lower sintering temperature and shorter sintering time of (1–x)CLT-xNMT ceramics than conventional heating methods. All of the (1–x)CLT-xNMT ceramics possess a single perovskite structure. With the increase of x, the dielectric constant (ε) shows a downward trend; the quality factor (Qf) drops first and then rises significantly; the resonance frequency temperature coefficient (τf) keeps decreasing. With excellent microwave dielectric properties (ε = 51.3, Qf = 13,852 GHz, τf = −1.9 × 10−6/°C), the 0.65CLT-0.35NMT ceramic can be applied to the field of mobile communications.

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