Oxidation resistance of Zr- and Hf-diboride composites containing SiC in air plasma up to 2600 K for aerospace applications

C. Pellegrini (1) , M. Balat-Pichelin (1) , O. Rapaud (2) , E. Bêche (1)

1 PROMES - Procédés, Matériaux et Energie Solaire
2 IRCER - Institut de Recherche sur les CERamiques

Microstructure-controlled and fully-dense ZrB 2 and HfB 2 composites were elaborated by Spark Plasma Sintering with two different amounts of SiC (20 and 30 vol%) added to improve their oxidation resistance using optimized sintering parameters. Oxidation of several samples in air plasma conditions, at 1000 Pa total pressure and from 1800 K up to 2600 K, was carried out. The mass variation of samples during oxidation duration of 300 s on a temperature plateau was followed. A four-step oxidation mechanism, identified by four singular mass variation behaviors depending on the oxidation temperature ranges, was proposed and detailed. The total normal emissivity was measured on pre-oxidized samples and high values around 0.90 were obtained from 1300 to 1900 K due to the presence of the oxide layer formed in air plasma conditions and this high emissivity is interesting for aerospace applications.

Mots clés: UHTC; SiC; Oxidation; Air plasma; High temperature

Domaines: Milieux fluides et réactifs; Matériaux

C. Pellegrini, M. Balat-Pichelin, O. Rapaud, E. Bêche. Oxidation resistance of Zr- and Hf-diboride composites containing SiC in air plasma up to 2600 K for aerospace applications. Ceramics International, 2021, 48 (2), pp.2177 - 2190. ⟨10.1016/j.ceramint.2021.09.310⟩. ⟨hal-03622720⟩