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Porous Cover Plates (now available in alumina and zirconia)

An ESL cover plate is a porous, fired ceramic plate used to cover green ceramic parts during firing. Porous alumina and zirconia plates find use in applications such as the manufacture of SOFC and other fuel cell electrolyte substrates, MEA's, interconnects, and other fuel cell assemblies.

The cover plate acts as a permeable flattening weight, reducing camber, warping or bowing during the initial firing of the part, while retaining gas permeability during organic removal. Use of a cover plate allows the replacement of a sintering or subsequent flat firing with a single-step firing process, thus reducing energy and other costs. The use of a porous weight or cover plate promotes creep flattening during the initial sintering process, without the grain growth experienced in a second firing. During this first firing a reduction in substrate camber, edge curling and rippling can be expected.

The cover plate may also be used as a refractory setter liner to avoid impurities from kiln or furnace furniture such as setters, saggars, batts or boats. Setter liners extend the life of kiln furniture, for example in ferrite and thermistor manufacturing. ESL cover plates can also find use as spacers between multiple green ceramic parts in a sintered stack, thus increasing kiln loading.

Alumina cover plates can be used up to a maximum temperature of 1550°C, and are re-usable, requiring only an occasional thermal re-flattening firing. Zirconia cover plates may be required when diffusion reactions or contamination by alumina is a possibility.

The data sheet (PDF file) gives details of the standard cover plate sizes currently available, but customized dimensions are also offered. The trial quantity sample pack available on this web site will include cover plates of several standard sizes.

Product Purpose PDF
42510-X Zirconia Cover Plates
Porous fired zirconia, available in various sizes
42520-X Alumina Cover Plates
Porous fired alumina, available in various sizes
Green Products are Lead-Free, Cadmium-Free

The above ESL materials are representative of the most common market requirements. ESL offers many other thick-film and ceramic tape products for specialized use which are not on this web site. ESL can also develop new materials to meet customer's specifications and needs. Please contact your nearest ESL representative listed on the Contact page for further information.