Title

Thermodynamic Analysis of ZrB₂-SiC Oxidation: Formation of a SiC-depleted Region

Abstract

A thermodynamic model was developed to explain the formation of a SiC-depleted layer during ZrB2-SiC oxidation in air at 1500°C. The proposed model suggests that a structure consisting of (1) a silica-rich layer, (2) a Zr-rich oxidized layer, and (3) a SiC-depleted zirconium diboride layer is thermodynamically stable. The SiC-depleted layer developed due to active oxidation of SiC. The oxygen partial pressure in the SiC-depleted layer was calculated to lie between 4.0 × 10−14 and 1.8 × 10−11 Pa. Even though SiC underwent active oxidation, the overall process was consistent with passive oxidation and the formation of a protective surface layer.

Department(s)

Materials Science and Engineering

Keywords and Phrases

SiC-Depleted Region; Thermodynamic Analysis; ZrB2-SiC Oxidation

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2007 American Ceramic Society, All rights reserved.


Share

 
COinS