Tape cast layer

Figure 7.28 Solvent profiles in a tape-cast layer, (a) Worst case, with high free surface evaporation rates. Solvent may be trapped in layers near the carrier surface. (b) Ideal case, where solvent decreases uniformly through the tape-cast layer. Heating the carrier side of the tape will promote ideal behavior.

Dry thickness Average thickness of the tape-cast layer after the solvent has been evaporated. 

Free handling Handling of a tape cast layer, whether manually or automatically, after the tape has been removed from the carrier. 

Green thickness Thickness of the green tape-cast layer. See also Dry thickness. 

M. Cologna, A. R. Contino, D. Montinaro and V. M. Sglavo, "Effect of Al and Ce doping on the deformation upon sintering in sequential tape cast layers for solid oxide fuel cells," Journal of Power Sources, vol. 93, p. 80-85, 2009. 

Once the structural support layers have been fabricated by extrusion or EPD for tubular cells or by tape casting or powder pressing for planar cells, the subsequent cell layers must be deposited to complete the cell. A wide variety of fabrication methods have been utilized for this purpose, with the choice of method or methods depending on the cell geometry (tubular or planar, and overall size) materials to be deposited and support layer material, both in terms of compatibility of the process with the layer to be deposited and with the previously deposited layers, and desired microstructure of the layer being deposited. In general, the methods can be classified into two very broad categories wet-ceramic techniques and direct-deposition techniques. 

PLD has also been utilized to produce bilayer electrolytes. In one study, aNiO-YSZ (anode support, tape cast)/NiO-SDC (AFL, screen-printed)/ScSZ-SDC (electrolyte bilayer, PLD)/SSC (cathode, screen-printed) cell showed excellent performance (0.5 and 0.9 W/cm2 at 550 and 600°C, respectively), with an OCV of 1.04 V at 600°C, indicating that the PLD technique was successful in depositing a sufficiently dense ScSZ electronic blocking layer to suppress electronic conduction normally observed across single-layer SDC electrolytes, and which typically result in lower OCV values (0.87 V, 600°C) [46, 127],... 

Layered ceramic Si3N4 composites on the basis of TiN or TiCN have been prepared by tape casting and hot pressing and showed highly anisotropic electrical and mechanical characteristics. One idea behind this development is the detection of crack formation under loading conditions by electrical conductivity measures [584, 585],... 

Lamination of green compacts or sheets, which are produced through the tape casting method, is a very important technique for graded material production. For this purpose, layers with different a (f SiAION ratio are used to obtain graded structures. Further details regarding these production techniques are given below. 

In the literature, there has been no report about production of functionally graded SiAION ceramics by tape casting. The main advantage of this method with respect to others is that continuous change in composition, microstructure and mechanical properties can be obtained by stacking controlled layer thicknesses of different tape compositions. 

Ceramic foils are produced continuously by tape-casting methods. These ceramic tapes consist of an organic binder and oxide powder material, for example, zirconia, titania or alumina. If it is possible to integrate the production process of a micro structured reactor into such a continuous process, production costs would decrease strongly. An early approach used unstructured ceramic foils to build up a micro reactor [159], The reactor consisted essentially of two functional layers, a reaction layer and a heating layer (Figure 4.102). 

It is also possible to retain the hydrothermally produced barium titanate particles in aqueous suspension to form the basis of a tape-casting slurry capable of producing < 3 /mi dielectric layers. This route avoids the risk of the formation of hard agglomerates on drying the precipitates. 

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