Abstract: Method for chemical vapor infiltration of refractory substances, wherein a porous structure is subjected in a reaction zone to the flow of a gas containing at least one gaseous precursor, wherein the partial pressure of the precursor and the dwell time of the gas are set at a given temperature in such a manner that a deposition reaction of the precursor occurs in the porous structure in the partial pressure range of the saturation adsorption and the reaction of the precursor is limited in each stage of the infiltration in such a manner that during the flow through the reaction zone no more than 50% of the precursor are deposited as a solid phase in the porous structure, and the exposure of the porous structure to the flow occurs in a stack of superimposed layers through ring-shaped vertical circumferential gaps (A, B) as well as through transverse gaps (C) which are open towards the circumferential gaps (A, B).

Abstract: Method for chemical vapor infiltration of refractory substances, wherein a porous structure is subjected in a reaction zone to the flow of a gas containing at least one gaseous precursor, wherein the partial pressure of the precursor and the dwell time of the gas are set at a given temperature in such a manner that a deposition reaction of the precursor occurs in the porous structure in the partial pressure range of the saturation adsorption and the reaction of the precursor is limited in each stage of the infiltration in such a manner that during the flow through the reaction zone no more than 50% of the precursor are deposited as a solid phase in the porous structure, and the exposure of the porous structure to the flow occurs in a stack of superimposed layers through ring-shaped vertical circumferential gaps (A, B) as well as through transverse gaps (C) which are open towards the circumferential gaps (A, B).

Abstract: The invention concerns a piston of finest grain carbon, having a bending strength of at least 100 MPa, a bending elongation >0.8%, an average interlayer distance c/2<0.35 nm, an average crystallite size in the c direction >5 nm and a heat conductivity of at least 10 W/mK, and a method for its production comprising: a) compacting of a polyaromatic mesophase powder to almost its final shape; b) heating of the green product at ambient pressure under a non-oxidizing atmosphere to a temperature of between 900 to 1300° C. and maintenance at this temperature; c) high-temperature treatment, thereby heating up to a temperature between 1400 and 2400° C.