Thermo-mechanical characterization of carbon-based ceramic foams for high temperature space application

Abstract

The successful development of aerospace reusable launch vehicles (RLV) require to realize effective thermal protection systems (TPS) for preserving spacecraft integrity from the severe thermal loads during re-entry phase. To such an aim, due to the need of reducing payload transportation costs, applied research is driven towards lightweight materials with advanced thermo-mechanical properties. Space TPS are often based on sandwich structures, where the core material has the main function of thermal insulation. Ceramic porous materials, as carbon (C) and silicon carbide (SiC) foams, represent ideal candidates for application as structural TPS component, thanks to both low density and significant thermal stability at very high temperatures. The paper presents a joint experimental study of carbon-based ceramic foams proposed as sandwich’s core for TPS design. A full thermal characterization of commercial C- and SiC-foam materials is reported, including measurements of thermo-mechanical combined stress, temperature-induced outgassing behavior and heat transfer properties. These latter, in particular, are studied by means of a robust numerical technique, known as the inverse method, which allows to evaluate materials thermal conductivity and heat capacity over a wide range of temperatures, thus establishing the required material behavior for potential use in spacecraft TPS.