Oxidation of ZrB 2-SiC ultra-high temperature composites over a wide range of SiC content

Abstract

The oxidation performance of ZrB 2-SiC ultra-high temperature ceramics with SiC content ranging from 20 to 80vol% has been evaluated at 1773K for 50h and at 2073K for 20min. Oxidation reaction pathways were interpreted using volatility diagrams of the ZrB 2-SiC system. At 1773K for 50h, all ZrB 2-SiC composites from 20 to 80vol% SiC formed a protective SiO 2 surface coating. Samples with ≤50vol% SiC developed a distinguishable SiC-depleted layer at 1773K and 2073K. High temperature torch testing for 20min at approximately 2073K revealed that samples with ≥65vol% SiC exhibit a depression under the torch flame. Samples rich in ZrB 2 were dominated by a ZrO 2 layer after a similar exposure. The overall weight density of ultra-high temperature ceramics can be reduced with improved oxidation performance at 1773K by adding at least 65vol% SiC.

Document Type

Article

DOI

https://doi.org/10.1016/j.jeurceramsoc.2012.05.021

Keywords

B. Microstructure-final, C. Thermal properties, D. Borides, D. SiC

Publication Date

11-1-2012

Journal Title

Journal of the European Ceramic Society

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