Abstract: A method for manufacturing composite materials from a parent substance containing silicon nitride and metal silicide, having fixed electrical properties. The molded articles are made, virtually with their final contours, prior to a sintering operation. The parent substance containing Si3N4 and a metal silicide is subjected to a gas pressure sintering in a nitrogenous atmosphere. The metal silicide is of the form Me5Si3, where Me is a metal. As a function of a sintering temperature, a lower limit of partial nitrogen pressures is selected so that Si3N4 is stable at the lower limit and an upper limit of the partial nitrogen pressures is selected so that Me5Si3 is stable at the upper limit. The resulting composite material is a silicon-containing composite material made of Si3N4 and the metal silicide. The metal silicide is selected from the group of Nb5Si3, V5Si3, Ta5Si3 and W5Si3.

Abstract: A sheath heater in a sheathed-type glow plug for diesel engines is described, having at least one generally internal insulation layer and at least one generally external conductive layer, both layers making up a ceramic composite structure. The sheath heater has a generally uniform overall cross-section, generally over its entire length, and, in the area of a tip of the sheath heater, the proportion of the insulation layer in the overall cross-section increases, whereas the proportion of the conductive layer in the overall cross-section decreases.

Abstract: A sheath heater in a sheathed-type glow plug for diesel engines is described, having at least one generally internal insulation layer and at least one generally external conductive layer, both layers making up a ceramic composite structure. The sheath heater has a generally uniform overall cross-section, generally over its entire length, and, in the area of a tip of the sheath heater, the proportion of the insulation layer in the overall cross-section increases, whereas the proportion of the conductive layer in the overall cross-section decreases.

Abstract: A method for manufacturing molded articles from a ceramic composite structure, in particular from a combination of tri-silicon tetranitride and a metal silicide, in which gas pressures up to 100 bar are used and the sintering additive content can be reduced to under 10 mass percent. This inert gas sintering pressure method makes possible larger molding free spaces in complicated geometrical structures of the molded articles, in contrast to the known methods. In addition, the electrical properties of this composite structure can be regulated by adjusting a defined nitrogen partial pressure.

Abstract: A method is proposed for manufacturing a pin heater that has a substantially internal insulating layer and an external conductive layer, the two layers composed of a ceramic composite structure, wherein before the pin heater is sintered, its shaping is accomplished by way of the ceramic injection molding technique or by cold combined axial/isostatic pressing.

Abstract: In a coagulator for systems for the purifying of exhaust gases of fossil fuels, in particular of exhaust gases from diesel internal-combustion engines, which has a housing (10), poled as counter-electrode, an electrode (11) arranged concentrically in the housing (10) and at high volotage and an electrically heatable insulator (13) for the insulated leading of the electrode (11) through the housing (10), the insulator (13) is designed in two parts for achieving a great high voltage resistance with relatively small overall dimensions and consists of a ceramic inner tube (17) and a ceramic protective tube (18) surrounding the latter. The heating conductor track (19) required for heating is applied in the shape of a coil as a thick-film conductor to the circumference of the inner tube (17) and the protective tube (18) is sintered on to the inner tube (17) in such a way that the parting line (14) between inner and protective tube (17, 18) is gas-tight (FIG. 1).