Electrical Conductivity Ceramics

A dimensionally stable anode consisting of an electrically conducting ceramic substrate coated with a noble metal oxide has been developed (55). Iridium oxide, for example, resists anode wear experienced ia the Downs and similar electrolytic cells (see Metal anodes). 

Titanium siUcides are used in the preparation of abrasion- and heat-resistant refractories. Compositions based on mixtures of Ti Si, TiC, and diamond have been claimed to make wear-resistant cutting-tool tips (157). Titanium siUcide can be used as an electric—resistant material, in electrically conducting ceramics (158), and in pressure-sensitive elastic resistors, the electric resistance of which varies with pressure (159). 

Good results are obtained with oxide-coated valve metals as anode materials. These electrically conducting ceramic coatings of p-conducting spinel-ferrite (e.g., cobalt, nickel and lithium ferrites) have very low consumption rates. Lithium ferrite has proved particularly effective because it possesses excellent adhesion on titanium and niobium [26]. In addition, doping the perovskite structure with monovalent lithium ions provides good electrical conductivity for anodic reactions. Anodes produced in this way are distributed under the trade name Lida [27]. The consumption rate in seawater is given as 10 g A ar and in fresh water is... 

Electrical conduction ceramics, 5 585-587 glasses, 5 592-593 Electrical conductivity. See also Conductivity of foams, 12 11 fillers and, 10 434 silver, 22 639... 

In the evaporation process the material to be deposited is heated to a temperature high enough to reach a sufficiently high vapor pressure and the desired evaporation or condensation rate is set. The simplest sources used in evaporation consist of wire filaments, boats of sheet metal or electrically conductive ceramics that are heated by passing an electrical current through them (Fig. 7.2). However, there are restrictions regarding the type... 

Use Varnish and paint drier, waterproofing paints, lead glass, electrically conductive ceramic coatings. 

H. Kawamura, et al., Electrical Conductive Ceramic Anodes in Sulfur-based Hybrid Cycle for Hydrogen Production , Proceedings International Hydrogen Energy Congress and Exhibition IHEC 2005. 

Key words Fuel Cell/Perovskite/Oxide Interlanthanoid/Electrical Conductivity Ceramics... 

The technology is developed and production with output of high-density electrical conductivity ceramics from stabilized zirconium oxide is organized in O.J.S.C. Ukrainian research institute of refractories named after A.S. Berezhnoy . The application of this ceramics is developed when using it in high-temperature electrochemical devices. 

As an alternative to solve the above-mentioned problem of Ni-YSZ anodes, electrically conductive ceramics have been explored, such as (Ce,Gd)02, Ti-YSZ, CUjO, PrjOj, M0O3, Sr Tig gNbg gOg, (La,Ca)Ti03, (La,Sr)Ti03, doped LaCrOj [21]. 

After grinding or materialographic lapping, the preparation process for ceramic materials continues with mechanical polishing. ElectropoUshing is only possible with electrically conductive ceramics, and ion polishing is uneconomical because of its low removal rates. 

Electrolytic etching can only be used with electrically conductive ceramic materials. Etching guidelines have been provided for materials based on NiO, TiC, TaC, SiC,... 

Ebonex is the trade name for an electrically conductive ceramic suboxide of titanium, having the approximate composition Ti407 and conductivity comparable to that of carbon. 

The corrosion mechanism entails the simple depletion of a passivating specie in the corrosive. This mechanism applies equally to nonconductive and electrically conductive ceramics. The passivating specie within the crevice is consumed by the corrosion reaction, making the crevice environment more corrosive than the bulk solution. Replacement of the passivating specie by diffusion is prevented by the occluded nature of the crevice therefore, the environment within the crevice remains more corrosive. The crevice grows as corrosion proceeds forming additional corrosion product, which further restricts diffusion. 

Mitsubishi Rayon Co. has reported the development of heat-storage and electrically conductive acrylic fibres with electrical conductivity > 10 S/cm and clothes for winter clothing and sportswear. These bicomponent fibres comprise a core-sheath structure, a core of P(AN/MA/Sod. methaUyl sulphonate) containing 15-70vol% white electrical conductive ceramic particles (e.g. W-P) and P (acrylonitrile/vinyl acetate) as a sheath. 

G. V. D. Goor, P. Sagesser, and K. Berroth, Electrically conductive ceramic composites. Solid State Ionics, 101-103 1163-1170,1997. 

In this chapter, it has been demonstrated that the fabrication process based on EPD method is expected to be an effective way to control the interfaces of SiC/SiC composites and to obtain high-performance SiC/SiC composites. From the viewpoint of the practical nse of continnous SiC/SiC composites, it is necessary to make the EPD process applicable to produce large and/or complex parts. In addition, the applicability of the fabrication process based on EPD should be extended to various CFCCs (oxides, glass, carbon, other non-oxides, non-electrically-conductive ceramic fibers and so on). In the future, the fabrication process of high-performance CFCCs based on EPD that is enviromnentally benign, low-cost and versatile will be expected to be realized. 

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