Abstract: Process for the fabrication of porous bodies mainly constituted by SiC containing ceramic with a microstructure which is interfused with micro-channels which consists of the process steps a) Provision of a pre-body made from cellulose or pulp b) Fabrication of an infiltration solution or a slurry consisting of (A) solvent, polysilazane, polysilane and/or polycarbosilane or (B) solvent, polysilazane and/or polysilane as well as active metallic fillers and/or passive ceramic fillers. c) Infiltrating the body with infiltration solution or slurry d) Cross-linking of the polysilazane, polycarbosilane and/or polysilane while generating a solid green body e) Ceramization through pyrolysis of the green body in an inert-gas atmosphere.

Abstract: A Positive Temperature Coefficient of Resistance resistor includes a ceramic material of the composition [(Ba.sub.1-e-x Sr.sub.x R.sub.e).sub.1-a M.sub.a ][(Ti.sub.1-b-d N.sub.b Q.sub.d)].sub.c O.sub.3, wherein M is a trivalent or quadrivalent element or a mixture of two or several of these elements; N is a quinquevalent or hexavalent element or a mixture of two or several of these elements; Q is a quadrivalent element or a mixture of two or several of these elements; R is a bivalent element or a mixture of two or several of these elements; and 0.5.ltoreq.x.ltoreq.1, a is 0 or 0.0003.ltoreq.a.ltoreq.0.3, and b is 0 or 0.0003.ltoreq.b.ltoreq.0.3, 0.8.ltoreq.c.ltoreq.1.2, 0.ltoreq.d.ltoreq.0.2, and 0.ltoreq.e.ltoreq.0.2.

Abstract: Electrically insulating ceramic gas supply plenums for solid electrolyte fuel cells in which the plenums are formed from a mixture of ceramic components and the proportions of the components in the mixture are adjusted to match the coefficient of thermal expansion of the plenum to that of the solid electrolyte. A preferred ceramic is formed from a mixture of MgO and Al.sub.2 O.sub.3 having a MgO/Al.sub.2 O.sub.3 molar ratio of from 1:1 and 7:1.