Fabrication of Y2Ti2O7 Transparent Ceramic by Spark Plasma Sintering

2021 ◽  
Vol 1035 ◽  
pp. 663-667
Author(s):  
Li Qiong An ◽  
Rong Wei Shi ◽  
Run Hua Fan ◽  
Takashi Goto
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Pyrochlore Structure ◽  
Transparent Ceramic ◽  
Sintered Body ◽  
Reactive Sintering ◽  
Uniform Microstructure ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma

Y2Ti2O7 transparent ceramic was fabricated by reactive sintering using spark plasma sintering at 1673 K for 2.7 ks. The sintered body exhibited a cubic pyrochlore structure and uniform microstructure with an average grain size of 2.9 μm. The transmittance reached 73% at a wavelength of 2000 nm after annealing at 1023 K for 21.6 ks.

Fabrication of Transparent La2Zr2O7 by Reactive Spark Plasma Sintering

2011 ◽  
Vol 484 ◽  
pp. 135-138 ◽  
Author(s):  
Li Qiong An ◽  
Akihiko Ito ◽  
Takashi Goto
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Wavelength Range ◽  
Single Phase ◽  
Sintering Temperature ◽  
Pyrochlore Structure ◽  
Sintered Body ◽  
Plasma Sintering ◽  
Spark Plasma

Transparent La2Zr2O7 with cubic pyrochlore structure was first fabricated by reactive spark plasma sintering using commercially available La2O3 and ZrO2 powders. Single phase of pyrochlore La2Zr2O7 was obtained at a sintering temperature of 1673 K and sintering pressure at 100 MPa for 2.7 ks. The La2Zr2O7 sintered body had a uniform grain size of 1.5 m and exhibited 68% transmittance in the wavelength range of 4–6 m.

Preparation of Fine-grained BaTiO3 Ceramics by Spark Plasma Sintering

2002 ◽  
Vol 17 (3) ◽  
pp. 575-581 ◽  
Author(s):  
Tomonari Takeuchi ◽  
Claudio Capiglia ◽  
Nalini Balakrishnan ◽  
Yasuo Takeda ◽  
Hiroyuki Kageyama
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Fine Powder ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Ferroelectric Domains ◽  
Spark Plasma ◽  
Ray Density ◽  
Permittivity Measurements

Dense BaTiO3 ceramics consisting of fine grains were prepared using fine powder (average grain size of 0.06 μm; BT006) as a starting material and the spark plasma sintering (SPS) method. The powder was densified to >95% of theoretical x-ray density by the SPS process, and the average grain size of the resulting ceramics was <0.5 μm; the particle size of the initial powder significantly affects the grain size of the resulting SPS pellets. Fixed-frequency (100 kHz), room-temperature permittivity measurements of the BT006-SPS ceramics showed relatively low values (3000–3500) compared with those (typically 5000) for SPS ceramics consisting of larger grains (approximately 1 μm). Lower permittivity was attributed to poor development of ferroelectric domains in the ceramics, which originated from incomplete development of the tetragonal structure as well as the presence of a local orthorhombic structure.

Manufacturing of Cu-15.0Zn-8.1Al Shape Memory Alloy Using Spark Plasma Sintering

2004 ◽  
Vol 449-452 ◽  
pp. 1109-1112 ◽  
Author(s):  
No Jin Park ◽  
Suck Jong Lee ◽  
In Sung Lee ◽  
Kyeong Sik Cho ◽  
Sung Jin Kim
Keyword(s):  
Grain Size ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Spark Plasma Sintering ◽  
Powder Size ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Fine Microstructure ◽  
Spark Plasma ◽  
Ar Gas

In order to control the grain size of Cu-15.0Zn-8.1Al shape memory alloy, the spark plasma sintering (SPS) technique was applied. The sintering processes were carried out under different atmospheres with a different powder size. The sintered bodies were denser under the Ar+4%H2 gas atmosphere than under the 100% Ar gas. By using the small-sized powders, the fine microstructure with average grain size of 2~3􀀀 was obtained. With the large-sized powders, the single martensitic phase was observed with the average grain size of 70~72􀀀 . When the starting powders with different sizes were mixed, it is confirmed that the average grain size of the manufactured alloys was 15􀀀 , but the distribution of grain size was not uniform.

Microstructural Development of SiC Ceramics by Liquid-Phase Sintering with Spark Plasma Sintering Technique

2006 ◽  
Vol 510-511 ◽  
pp. 1022-1025 ◽  
Author(s):  
Mikinori Hotta ◽  
Junichi Hojo
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Liquid Phase Sintering ◽  
Molar Ratio ◽  
Microstructural Development ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
N2 Atmosphere ◽  
Average Grain Size ◽  
Spark Plasma

Sub-micron and nano-sized β-SiC powders were sintered with AlN and Y2O3 as sintering additives by spark plasma sintering (SPS). The sintered densities reached >95% of theoretical with a different molar ratio of AlN to Y2O3 at total amount of 10vol% and temperature of 1900oC for 10min in N2 atmosphere under a pressure of 30MPa. With increasing amount of the AlN additive, the size of SiC grains decreased and the shape changed from globular to columnar. The fully densified SiC at AlN:Y2O3=95:5mol% had an average grain size of 0.5-1µm and 50-100nm in diameter by using sub-micron and nano-sized SiC starting powders, respectively. Flexural strength of the specimen having grain size of 0.5-1µm was approximately 1200MPa at room temperature.

Preparation of TiB2-TiN and TiN-B Powders and their Processing

2012 ◽  
Vol 527 ◽  
pp. 32-37
Author(s):  
J. Grabis ◽  
Ints Šteins ◽  
Dz. Rašmane
Keyword(s):  
Grain Size ◽  
Relative Density ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Amorphous Boron ◽  
Reactive Sintering ◽  
Plasma Technique ◽  
Sintering Time ◽  
Plasma Sintering ◽  
Spark Plasma

TiN and TiN/TiBSubscript text2 nanoparticles with crystallite size of TiN in the range of 27–38 nm and TiBSubscript text2 in the range of 55–90 nm have been prepared by thermal plasma technique. The prepared nanoparticles and mechanical mixture of TiN with amorphous boron have been densified using spark plasma sintering and the microstructure and density of the samples were compared. The relative density of the samples with content of TiBSubscript text2 about 36 wt.% is in the range of 95.9–97.1% in dependence on the precursors. The higher relative density of the samples provided reactive sintering of TiN/B powder. The grain size of the composites in the range of 0.5–3 µm testified that spark plasma sintering intensified the grain growth in despite of the short sintering time.

Transparent nanocrystalline MgO by rapid and low-temperature spark plasma sintering

2004 ◽  
Vol 19 (9) ◽  
pp. 2527-2531 ◽  
Author(s):  
Rachman Chaim ◽  
Zhijian Shen ◽  
Mats Nygren
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
Oxygen Vacancy ◽  
Spark Plasma Sintering ◽  
Color Centers ◽  
Reducing Atmosphere ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma ◽  
Nanocrystalline Mgo

We investigated superfast densification of nanocrystalline MgO powders by spark plasma sintering (SPS) between 700 °C and 825 °C under applied pressures of 100and 150 MPa. Fully-dense transparent nanocrystalline MgO with a 52-nm average grain size was fabricated at 800 °C and 150 MPa for 5 min. In-line transmissionsof 40% and 60% were measured compared to MgO single crystal, for the yellowand red wavelengths, respectively. Densification occurs by particles sliding over each other; the nanometric grain size and pores lead to the optical transparency. The light brownish color of the nanocrystalline MgO is due to the oxygen vacancy color centers, originating from the reducing atmosphere of the SPS process.

Controlled Atmosphere Thermal Treatment for Pyrochlore Phase Elimination of PMN-PT/CFO Prepared by Spark Plasma Sintering

2014 ◽  
Vol 975 ◽  
pp. 274-279 ◽  
Author(s):  
Diego Seiti Fukano Viana ◽  
José Antônio Eiras ◽  
William Junior Nascimento ◽  
Fabio Luiz Zabotto ◽  
Ducinei Garcia
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Single Phase ◽  
Magnetoelectric Effect ◽  
Pyrochlore Phase ◽  
Practical Applications ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma ◽  
Phase Elimination

Multiferroics are interesting materials which present more than one ferroic property and have a great potential for practical applications [,,]. In addition, the coupling of magnetic and electric properties, the magnetoelectric effect (ME), offers news possibilities to applications [2,]. The magnetoelectric effect can be observed in single-phase materials like LuFe2O4, BiFeO3, etc. [1,] or in composites like PMN-PT/CFO, BaTiO3/CoFe2O4, etc. The ME composites have advantages over single-phase materials. They are easier to fabricate, less expensive, and have a wider range of working temperatures than single-phase materials []. However, some parameters that enhance the ME response need to be optimized. These parameters are the composition, the microstructure (grain size, grain orientation) and sintering parameters [6]. Thus, this work attempts to create a synthesis protocol to prepare the ME composite PMN-PT/CFO by Spark Plasma Sintering (SPS) keeping the average grain size as small as possible.

Optical and Microwave Dielectric Properties of Transparent MgAl2O4 Ceramics

2013 ◽  
Vol 647 ◽  
pp. 758-761
Author(s):  
Ping Fu ◽  
Wen Zhong Lu ◽  
Wen Lei ◽  
Yong Xu ◽  
Xian Long Lu
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Spark Plasma Sintering ◽  
Microwave Dielectric Properties ◽  
Temperature Range ◽  
Microwave Dielectric ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma ◽  
Sintering Processes

Transparent polycrystalline MgAl2O4ceramics were fabricated by using spark plasma sintering (SPS) technique at a temperature range from 1275 °C to 1400 °C. The average grain size of the samples fabricated at optimal sintering processes was 345 nm. The in-line transmittance of the sintered ceramics can be as high as 70% at 550 nm and 82% at 2000 nm, respectively. The optimal microwave dielectric properties (εr = 8.38, Q×f = 54000 GHz and τf = -74 ppm/°C) were achieved at 1325°C for 20 min.

scholarly journals Comparative Study of Reactive and Non-reactive Spark Plasma Sintering Routes for The Production of TaB2-TaC Composites

2021 ◽  
Author(s):  
Melis Kaplan Akarsu ◽  
Ipek Akin ◽  
Filiz Sahin ◽  
Gultekin Goller
Keyword(s):  
Spark Plasma Sintering ◽  
Oxidation Behavior ◽  
Sintering Temperature ◽  
Single Step ◽  
Reactive Sintering ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Significant Difference ◽  
Spark Plasma

Abstract The influence of two different spark plasma sintering-based processing routes (i.e., reactive SPS (RSPS) and non-reactive SPS) on the properties of TaB2-TaC composites was investigated. Ta2O5 and B4C powders were used as starting materials in the RSPS method, and synthesis and densification of TaB2-TaC composites were accomplished in a facile single step. The effect of sintering temperature and time on the microstructure and densification of the in-situ RSPS were investigated. The obtained results were compared with non-reactive spark plasma sintered TaB2-TaC composites. The highest densification (~ 99.5 %) was achieved for the TaB2-TaC composite with 6.64 vol% TaC after reactive sintering at 1550 °C under 40 MPa with a 5 min holding time. Although lower SPS temperature was used in the RSPS method, better densification and higher Vickers hardness were obtained compared to the non-reactive SPS. While platelet-shaped TaC formation was observed in both processes, the average grain size was smaller in the sample produced by the RSPS method. On the other hand, no significant difference was detected in fracture toughness and oxidation behavior of the composites produced by RSPS and non-reactive SPS.

Spark Plasma Sintering of Two Commercial Al2O3 Powders

2011 ◽  
Vol 412 ◽  
pp. 336-339 ◽  
Author(s):  
Zhen Hua Liu ◽  
Qin Ma ◽  
Jin Jun Lu
Keyword(s):  
Grain Size ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma

Al2O3 ceramic is prepared by spark plasma sintering (SPS) using two commercial α-Al2O3 powders at elevated sintering temperature. The relative density and average grain size of the prepared Al2O3 ceramics are measured and compared. One α-Al2O3 powder has good sintering property because the relative density of the prepared α-Al2O3 ceramic is higher than 97% while another α-Al2O3 powder has poor sintering property.

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