Ceramic honeycomb body for lightweight structures and corresponding production method

A honeycomb body (1) of a composite material for fire-resistant lightweight structures, for use as a core (41) or for producing a core (41) between two cover layers (44) of a lightweight sandwich structure, the honeycomb body (1) comprising honeycomb cells (12) with a cross-section in the L/W plane, cell walls (13) of the honeycomb cells (12) being produced from a composite material, the composite material at least comprising

• a support, and
• a matrix, the support being embedded in the matrix,
• wherein the matrix comprises a silicon-based ceramic material selected from the group consisting of silicon carbide, silicon oxycarbide, silicon nitride, silicon carbonitride and silicon-boron carbonitride, wherein, over the entire height of the cell walls (13) in the T direction perpendicular to the L/W plane, the matrix has a mass fraction of the silicon-based ceramic material of at least 30 wt. %, wherein the mass fraction of the silicon-based ceramic material in the matrix in the central region along the T direction deviates by less than 20 wt. % from the mass fraction of the silicon-based ceramic material in the matrix in the end regions of the height of the cell walls (13),
• wherein a mass fraction of free carbon in the matrix amounts to at least 1 wt. %.