Abstract: A process for impregnating porous carbon bodies, in particular carbon fiber-reinforced carbon bodies, protects against oxidation by atmospheric oxygen. The open pores present in the carbon body are lined both in the interior and on the surfaces with a low viscosity gel and/or sol, formed from refractory and/or non-combustible inorganic compounds, as antioxidants. The antioxidant applied has a layer thickness of about 1 micrometer and is highly elastic. It adapts very well to the thermal expansions of the carbon body and is resistant to heat up to above 1000.degree. C.

Abstract: A heat-insulating lining for a gas turbine which consists of a mat formed of ceramic fibers that is provided on its side facing the hot gas with a metal-oxide-containing layer, especially Al.sub.2 O.sub.3. The mat to be provided with the ceramic layer should possess a gross density of 350 to 450 kg/m.sup.3 and the fibers in the mat which are in contact with the metal oxide-containing layer are to be predominantly so oriented that the longitudinal axis of the fibers forms an angle of 30.degree. to 90.degree. with the metal oxide-containing layer. It is preferred if the fibers form an approximately right angle with the metal oxide-containing layer. The thus made coated heat-insulating linings possess a good mechanical stability with respect to the hot gases as well as an adequate thermo-shock resistance.