Titanium, alternate ceramics

Evaporative decomposition erf solutions and spary pyrolysis have been found to be useful in the preparation of submicrometer oxide and non-oxide particles, including high temperature superconducting ceramics [819, 820], Allowing uniform aerosol droplets (titanium ethoxide in ethanol, for example) to react with a vapor (water, for example) to produce spherical colloidal particles with controllable sizes and size distributions [821-825] is an alternative vapor phase approach. Chemical vapor deposition techniques (CVD) have also been extended to the formation of ceramic particles [825]. 

Permeable layer reactors consist of thin, porous metal or ceramic substrates onto which titanium dioxide is coated in a manner that allows for flowing fhrough the porous substrates. The flow can be either perpendicular to the surface of the porous media or alternatively may combine perpendicular and parallel vectors. An example of such a reactor was presented by Tsuru et al. (2006). Here, a titania membrane (pore sizes 2.5-22 nm) was prepared... 

PEM water electrolysis cells have a potential advantage over traditional low-temperature electrolysis cells (e.g., KOH in water electrolytes with palladium, titanium, or alternative metal or ceramic electrodes ) because PEM devices have been... 

Later, Papet [58] presented an alternative process for preparing mbular ceramic cross-fiow filtration membranes. Papet s method consists of the casting of mbular mineral microfiltration membranes with titanium dioxide suspensions. The deposited particles on the porous support were then compressed and finally, the layer was consolidated by firing. 

Active metal brazing (AMB) is a process to braze metals, such as Kovar , titanium, copper, and molybdenum, to ceramics. The process does not require a metallization on the ceramic. For this chapter, only copper brazing will be addressed. The AMB process is used by some manufacturers as an alternative to DBC as it provides higher adhesive strength while using a less critical furnace profile. It also does not rely on oxide formation as in the DBC process. 

Another approach is to select steels that qualify when coated with a coating [2], that either prevents direct contact with the electrolyte and is not oxidized at the cathode. In this respect, ceramic metal nitride coatings are considered (Cr, Ti, TiAl nitride) [78]. If the coating is perfectly dense and stable, any base material could be applied. Alternative base metals being considered are aluminum or titanium [79]. 

The purposes of the grid are to hold the active material mechanically and conduct electricity between the active material and the ceU terminals. The mechanical support can be provided by nonmetallic materials (polymer, ceramic, rabber, etc.) inside the plate, but these are not electrically conductive. Additional mechanical support is sometimes gained by the construction method or by various wrappings on the outside of the plate. Metals other than lead alloys have been investigated to provide electrieal conductivity, and some (copper, aluminum, silver) are more conductive than lead. These alternate conductors are not corrosion-resistant in the sulfuric acid electrolyte and are often more expensive than lead alloys. Titanium has been evaluated as a grid material it is not corroded after special surface treatments but is very expensive. Copper grids are used in the negatives of some submarine batteries. 

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