Characterization and Process of New Metal Diboride Compound for TPS Applications

§** A joint research work financed by CIRA and performed with the support of the CNR-ISTEC have been performed with the aim to evaluate and to assess the use of non-conventional metal diboride compounds in the manufacturing of slender-shaped hot structures for re-entry vehicles. The results of the metal diborides trade-off and the characterisation of the selected material are reported in this paper. A description of the material process employed is also provided. Different diboride compositions, both hafnium- and zirconium- based, have been considered and characterized in their mechanical, thermal and oxidation resistance behaviour: as a result of this trade-off, the most promising composition was chosen and further characterised. The obtained results highlight an excellent potential for the selected material. A scaled hot structure demonstrator, to be on-ground tested at CIRA Scirocco Plasma Wind Tunnel, have also been manufactured.