The Oxidation of ZrB<sub>2</sub>/MoSi<sub>2</sub> Ceramics in Dissociated Air: The Influence of the Elaboration Technique
Ludovic Charpentier,
Pedro Miranda,
Hugo Tallaron,
Florencia M. Nogales,
Álvaro Sández-Gómez,
Eric Bêche,
Marianne Balat-Pichelin
Affiliations
Ludovic Charpentier
PROMES-CNRS, 7, Rue Du Four Solaire, 66120 Font-Romeu Odeillo, France
Pedro Miranda
Department of Mechanical, Energy and Materials Engineering, Industrial Engineering School, University of Extremadura, Avda. de Elvas s/n, 06006 Badajoz, Spain
Hugo Tallaron
PROMES-CNRS, 7, Rue Du Four Solaire, 66120 Font-Romeu Odeillo, France
Florencia M. Nogales
Department of Mechanical, Energy and Materials Engineering, Industrial Engineering School, University of Extremadura, Avda. de Elvas s/n, 06006 Badajoz, Spain
Álvaro Sández-Gómez
Department of Mechanical, Energy and Materials Engineering, Industrial Engineering School, University of Extremadura, Avda. de Elvas s/n, 06006 Badajoz, Spain
Eric Bêche
PROMES-CNRS, 7, Rue Du Four Solaire, 66120 Font-Romeu Odeillo, France
Marianne Balat-Pichelin
PROMES-CNRS, 7, Rue Du Four Solaire, 66120 Font-Romeu Odeillo, France
In order to investigate the most extreme conditions in which materials potentially applicable in reusable thermal shields can be operated, ultra-high-temperature ZrB2 ceramics with 20 vol.% MoSi2 were prepared using two different techniques, cold isostatic pressing (CIP) and robocasting (RC, an additive manufacturing technique), followed by consolidation using pressureless spark plasma sintering (SPS). The oxidation behavior of the resulting materials was analyzed in low-pressure dissociated air at three different temperatures, namely 1800, 2000 and 2200 K. Using XRD and surface and cross-section SEM (coupled with EDS), zirconia was found to form at all three temperatures, while silica was only present at 1800 K, with gaseous SiO forming at a higher temperature. The elaboration technique influences the density of the ceramic, and less dense materials undergo deeper oxidation. This investigation suggests that 2000 K is already beyond the maximum temperature threshold at which damage to ceramics is limited by the formation of protective silica. This study confirms that the selected material is a promising candidate for thermal protection applications.