|About this Abstract
||MS&T23: Materials Science & Technology
||High Temperature Corrosion and Degradation of Structural Materials
||Oxidation of Additively Manufactured AM-ZrB2-30vol%SiC under CO2 Exposure
||Marharyta Lakusta, William G. Fahrenholtz, Jeremy L. Watts, Gregory E. Hilmas, David W. Lipke
|On-Site Speaker (Planned)
A comprehensive kinetic study of the oxidation behavior of additively manufactured AM-ZrB2-30vol%SiC in CO2 exposure at high temperatures (700-1000°C) for various durations (24-192h) has been presented. The temperature and time dependencies of the oxidation rate constants and a high-pressure effect (supercritical conditions P=25MPa, T=650oC) were analyzed and discussed. The rate-limiting kinetic step was identified through the examination of oxide thickness and activation energy data. The predominant mechanism of oxidation in CO2 was found to be the diffusion of oxidizer through the formed protective oxide scale, as indicated by parabolic-like oxide thickness growth. The oxidation rates for AM-ZrB2-30vol%SiC samples exposed to CO2 and air were compared, revealing that while the composition of the oxide scales consisting of ZrO2, B2O3, SiO2 was identical in both environments, the oxidation rates were at least two times lower in CO2 exposure.