Abstract: A central electrode for spark plugs of internal-combustion engines, comprising a core of a highly heat-conductive base metallic material which is provided in the region of the firing tip with a precious metal casing consisting of silver or a silver alloy with predominantly silver content. At the boundary surface between the core material and the casing at least one interlayer is provided which is oxygen-impermeable and/or prevents the formation of a eutectic between the core material and the material of the casing.

Abstract: A shaped part made of a composite material having shape memory properties is intended to be assembled in such a way that various changes in shape, including complex changes, take place in dependence on the temperature. This is achieved by providing that the shaped part has several sections which have shape memory properties and which are coupled together with one another in such a way that independent results of the shape memory effect cause temperature-specific changes in the shape of the shaped part, in the course of which the shaped part assumes the same number of permanent and/or reversible shapes as the number of sections having shape memory properties.