Thick films of ceramic superconducting, electro-ceramic materials

2002 ◽  
Vol 74 (11) ◽  
pp. 2083-2096 ◽  
Author(s):  
H. Altenburg ◽  
J. Plewa ◽  
G. Plesch ◽  
O. Shpotyuk

The use of thick films becomes more and more important in particular for electronic and microelectronic applications. The term “thick film ” does not relate so much to the thickness of the film but more to the kind of deposition. Thick films are made by low-priced processes such as doctor (dr) blading, screen-printing, or spraying methods, etc. The preparation of thick films of ceramic material by these methods generally implies a processing sequence of the following steps: preparation of the oxide powders; preparation of pastes and slurries; painting/printing, etc.of the pastes onto a suitable substrate; drying at low temperature; and sintering at high temperature to get a consolidated layer. These technologies and the fabricated thick films of thermoresistive and superconducting materials will be discussed.

2020 ◽  
Vol 10 (10) ◽  
pp. 59-67
Author(s):  
Victor N. ANTIPOV ◽  
◽  
Andrey D. GROZOV ◽  
Anna V. IVANOVA ◽  
◽  
...  

The overall dimensions and mass of wind power units with capacities larger than 10 MW can be improved and their cost can be decreased by developing and constructing superconducting synchronous generators. The article analyzes foreign conceptual designs of superconducting synchronous generators based on different principles: with the use of high- and low-temperature superconductivity, fully superconducting or only with a superconducting excitation system, and with the use of different materials (MgB2, Bi2223, YBCO). A high cost of superconducting materials is the main factor impeding commercial application of superconducting generators. In view of the state of the art in the technology for manufacturing superconductors and their cost, a conclusion is drawn, according to which a synchronous gearless superconducting wind generator with a capacity of 10 MW with the field winding made of a high-temperature superconducting material (MgB2, Bi-2223 or YBCO) with the «ferromagnetic stator — ferromagnetic rotor» topology, with the stator diameter equal to 7—9 m, and with the number of poles equal to 32—40 has prospects for its practical use in the nearest future.


2018 ◽  
Vol 170 ◽  
pp. 04008
Author(s):  
O. Gatsa ◽  
P. Combette ◽  
E. Rozenkrantz ◽  
D. Fourmentel ◽  
C. Destouches ◽  
...  

In the contemporary world, the measurements in hostile environment is one of the predominant necessity for automotive, aerospace, metallurgy and nuclear plant. The measurement of different parameters in experimental reactors is an important point in nuclear power strategy. In the near past, IES (Institut d’Électronique et des Systèmes) on collaboration with CEA (Commissariat à l’Energie Atomique et aux Energies Alternatives) have developed the first ultrasonic sensor for the application of gas quantity determination that has been tested in a Materials Testing Reactor (MTR). Modern requirements state to labor with the materials that possess stability on its parameters around 350°C in operation temperature. Previous work on PZT components elaboration by screen printing method established the new basis in thick film fabrication and characterization in our laboratory. Our trials on Bismuth Titanate ceramics showed the difficulties related to high electrical conductivity of fabricated samples that postponed further research on this material. Among piezoceramics, the requirements on finding an alternative solution on ceramics that might be easily polarized and fabricated by screen printing approach were resolved by the fabrication of thick film from Sodium Bismuth Titanate (NBT) piezoelectric powder. This material exhibits high Curie temperature, relatively good piezoelectric and coupling coefficients, and it stands to be a good solution for the anticipated application. In this paper, we present NBT thick film fabrication by screen printing, characterization of piezoelectric, dielectric properties and material parameters studies in dependence of temperature. Relatively high resistivity in the range of 1.1013 Ohm.cm for fabricated thick film is explained by Aurivillius structure in which a-and b-layers form perovskite structure between oxides of c-layer. Main results of this study are presented and discussed in terms of feasibility for an application to a new sensor device operating at high temperature level (400°). Piezoelectric parameters enhancement and loss reduction at elevated temperatures are envisaged to be optimized. Further sensor development and test in MTR are expected to be realized in the near future.


2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000053-000057
Author(s):  
Jaroslaw Kita ◽  
Sven Wiegärtner ◽  
Alistair Prince ◽  
Peter Weigand ◽  
Ralf Moos

Abstract The application of thermocouples as temperature sensors has been well known and has already been established for many years. However, for classical thick-film technology using screen-printing and firing, no standardized solutions exist. The here-presented newly developed PtRh thick-film compositions (90% Pt,10% Rh) allows to construct thick-film type S thermocouples (Pt/PtRh), following the IEC temperature characteristics. They can be fired in air, and therefore can be easily integrated into existing thick-film components and devices. In an earlier study, the new Pt-Rh composition was successfully tested on alumina substrates. Their electrical characteristics is equal with classical wire type S thermocouples. This study continues the investigations of thick-film thermocouples. We tested the newly developed pastes for high temperature applications on alumina substrates and evaluated the application of the new screen-printable type S thermocouples on LTCC ceramics. Three possible configurations were investigated: deposited on already fired LTCC substrates (post-fired), screen-printed and co-fired with LTCC tapes on the top surface as well as as buried structures. The paper presents the results of our evaluation and discusses further possible applications.


2021 ◽  
Vol 12 (2-2021) ◽  
pp. 188-191
Author(s):  
T. O. Obolkina ◽  
◽  
M. A. Goldberg ◽  
S. V. Smirnov ◽  
O. A. Antonova ◽  
...  

In this work, we studied the effect of complex additives containing Na2Si2O5 and Ni, Zn oxides on the properties and sintering temperature of a ceramic material 3Y-TZP- Al2O3 with an aluminum oxide (Al2O3) content of 5 wt %. It was shown that the introduction of complex additives promoted an increase in the flexural strength of ceramic materials. The greatest strength (445±22 МПа) was achieved by sintering at 1250 °C on the composition with 5 wt % Na2Si2O5 and 0.33 mol % Zn.


2018 ◽  
Vol 35 ◽  
pp. 62-85
Author(s):  
Gaida Sedmale ◽  
Māris Rundāns ◽  
Mārtiņs Randers ◽  
Ingunda Šperberga ◽  
Andris Cimmers

Darbā dots ieskats par iespējām izmantot Latvijas minerālās izejvielas kā bāzi vai  piedevu  keramikas  materiālu  (eko-materiālu)  izstrādei ar dažādu pielietošanas aspektu, to skaitā parādīt iespēju šo materiālu ieguves tehnoloģisko procesu optimizēšanai virzībā uz to apdedzināšanas temperatūras samazināšanu, līdz ar to reducējot kaitīgu gāzveida izmešu nonākšanu vidē. Parādīti darbu rezultāti laika periodā no 2007. g. līdz 2017. g. Tiek apskatīti un analizēti sekojoši pētījumi:neapstrādāta māla pielietošana atkritumu deponēšanas vietu noblīvēšanai;daļēji dehidratizēta māla pielietošana Cr3+, Cr6+, Zn2+ un Cu+ jonu sorbcijai, kas veidojas galvanisko procesu notekūdeņos; poru saturošas augsttemperatūras keramikas izstrāde no jauktiem izejvielu maisījumiem, kas nodrošina pietiekamu gāzveida fāzes izveidošanos keramikas apdedzināšanas procesā, veidojot poras, lai pielietotu par filtrēšanas/attīrīšanas materiālu;illīta māla piedevu izmantošana, lai pazeminātu augsttemperatūras blīvas keramikas saķepināšanas/apdedzināšanas temperatūru, iegūstot ilgspējīgu mehāniski un termiski izturīgu produktu; kā arī tehnoloģiskie procesi, kas nodrošina porainas, siltumu izolējošas keramikas materiāla ieguvi pie pazeminātām temperatūrām (ģeopolimēru metode).Mineral Raw Materials of Latvia for Development of Eco-CeramicsThe paper gives an insight into the possibilities to use Latvian mineral raw materials as a base or additives for the development of ceramic materials (eco- materials) with different application aspects, including showing the possibility of optimizing the technological processes of these materials towards the reduction of their firing temperature, thereby reducing the release of harmful gaseous effluents into the environment.The results of the works that are reported in the period were obtained from  2007 to 2017. The following studies are reviewed and analyzed: the use of untreated clay for the sealing of waste deposits; the use of partly dehydrated clay for sorption of Cr3+,6+, Zn2+ and Cu2+, which have formed in galvanic processes; the development of porous high temperature ceramics from mixes  of mineral raw materials and synthetic additives that provide a sufficient gas phase  formation in the firing process and consecutively to form pores in obtained ceramic material; the use of illite clay additives to reduce the temperature of sintering of high temperature dense mechanical and thermally durable ceramics, as well as technological processes that ensure the production of porous, heat-insulating ceramic materials at reduced temperatures (geopolymer method).


2021 ◽  
Vol 10 (3) ◽  
pp. 277-280
Author(s):  
Vaishali T Salunke ◽  
P.B. Buchade ◽  
A.D. Shaligram ◽  
R.Y. Borse

Nowadays nanomaterial is used widely because of their change in characteristics from bulk to nano. In this paper the preparation of ZnO nano powder by self-combustion high temperature method was discussed. The solution of Zinc Nitrate as a precursor and dextrose as a fuel was kept in furnace at 400,500 and 600 0C for 5-15 minute to complete the reaction. The ZnO thick films were prepared by screen printing and fired at 650 0C. The effect of different synthesis temperature on ZnO thick films were study by FTIR analysis. The applications of zinc oxide powders were discussed in these papers.


Author(s):  
P. Veyssière ◽  
J. Castaing

Brittleness is a feature common to many ceramic materials at low temperature. However, in some cases, they remain ductile as, for instance, crystals with the rocksalt structure which can be deformed down to 4.2 K: their properties are very similar to those of metals and will not be described in the present paper (for a review, see). Usually, macroscopic strain can be obtained only at temperatures larger than 0.5 TM, where TM is the melting temperature. The resulting microstructures consist in networks where dislocation climb is shown by TEM to have played an extensive role. Nevertheless, despite the active atomic diffusion pointed out in the high temperature experiments, what controls the transition between ductility and brittleness is probably not related to the rate of matter transport. Rather, the reasons for this transition rely on crystal structure and chemical bonding, which are of prime importance in the choice of Burgers vectors and slip plane, in the mobility of dislocations...


2002 ◽  
Vol 56 (4) ◽  
pp. 518-521 ◽  
Author(s):  
Bong Yeon Lee ◽  
Chae Il Cheon ◽  
Jeong Seog Kim ◽  
Kyu Seok Bang ◽  
Jun Chul Kim ◽  
...  

2000 ◽  
Vol 39 (Part 1, No. 9B) ◽  
pp. 5548-5551 ◽  
Author(s):  
Tomoaki Futakuchi ◽  
Kunitaka Nakano ◽  
Masatoshi Adachi

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