Poröses Hybridbauteil bestehend aus oxidkeramischen Verbundwerkstoffen und papierabgeleiteter Keramik für Hochtemperaturisolation im Kraftfluss

At high temperatures up to 1000 °C, there are no insulation materials that combine low thermal conductivities < 1.5 W/mK, high hot compressive strengths of over 150 MPa and a damage-tolerant, quasiductile fracture behavior and are therefore suitable for use in force flow, e.g. in tools for hot forming. Due to the functional separation between the oxide fiber composites (pressure stability, quasi ductility) and the paper-derived ceramic (low thermal conductivity) in the hybrid insulation described above, an insulation material that meets these requirements is now available for the first time. Due to the high porosity of the oxide fiber composites and depending on the used raw materials, they already have relatively low thermal conductivities in the range of 2 - 6 W/mK, but still not sufficient for the mentioned applications. Only in combination with paper-derived ceramics can the average thermal conductivity of the component be reduced to below 1.5 W/mK, whereby the paper-derived ceramics does not contribute to the compressive strength The exclusive use of oxide fiber composites would also be too cost-intensive. A further advantage of the hybrid insulation according to the invention is its wide application range from < -200 °C to 1000 °C and above, under oxidative as well as corrosive conditions.