Microstructural Features of Oxide Scales Formed on Zirconium Diboride Materials
Both ZrB2 and ZrB2 + 20 v/o SiC have been oxidized in oxygen over the range 900° to 1500°C. The microstructural features of the oxide scales formed under these conditions are studied as a function of temperature and reaction time. Techniques used to characterize the oxide products include x-ray diffraction, scanning electron microscopy and electronprobe microanalysis. A glassy B2O3 is one of the oxidation products at temperatures below 1100°C, resulting in protective behavior. At higher temperatures the formation of an SiO2-base glass imparts additional protection to ZrB2 + 20 v/o Sic.
KeywordsOxide Scale Boron Oxide Glass Layer Columnar Growth Gravimetric Data
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