Thermo-mechanical performance of an ablative/ceramic composite hybrid thermal protection structure for re-entry applications

Hybrid thermal protection systems for aerospace applications based on ablative material (ASTERM (TM)) and ceramic matrix composite (SICARBON (TM)) have been investigated. The ablative material and the ceramic matrix composite were joined using graphite and zirconia zirconium silicate based commercial high temperature adhesives. The thermo-mechanical performance of the structures was assessed from room temperature up to 900 degrees C. In all the joints there is a decrease of shear strength with the increase of temperature. Analysis of the fractured surfaces showed that above 150 degrees C the predominant mode of fracture is cohesive failure in the bonding layer. The joints fabricated with the zirconia zirconium silicate based adhesive present the best performance and they have the potential to be used as hybrid thermal protection systems for aerospace applications in the temperature range 700-900 degrees C.European Project ‘‘HYDRA’’ (G.A. n. 283797) with the financial support by the European Commission

Performance of cork and ceramic matrix composite joints for re-entry thermal protection structures

In view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on cork and ceramic matrix composites are investigated. Joints of NORCOAT LIÈGE cork with C/Csingle bondSiC ceramic matrix composite were fabricated using a) high temperature commercial inorganic adhesives and b) in-situ polymerization of the cork on top of the CMC. Mechanical shear tests under ambient conditions and in liquid nitrogen are carried out. The ultimate shear strength of all the adhesive joints at room temperature varies between 0.52 and 0.78 MPa and is similar to that of the in-situ joints. At liquid nitrogen temperature the shear strength is enhanced by up to 80%, but the ultimate shear strain decreases up to 55%. The failure mode is discussed for the two types of the fabrication procedure.FP7 framework, European Project ‘‘HYDRA’’ (G.A. n. 283797), European Commission