Characterization of Al2O3 composites containing NANO-Mo particulates III: Atmospheric reactions of Mo
Journal
Scripta Materialia
Journal Volume
44
Journal Issue
7
Pages
1025-1031
Date Issued
2001
Author(s)
Abstract
The Mo phase is oxidized above 300°C in atmosphere, and the newly formed MoO3 tends to sublimate above 380°C. The oxidation follows a parabolic law and shows an activation energy of 203-228 kJ/mol. The activation energy of the sublimation at temperatures greater than 650°C is about 268 kJ/mol. The sublimation becomes vigorous enough to result in mass loss for the overall reaction when the temperature exceeds 650°C. The oxidation of the Mo/alumina composites shows similar behaviors as the pure Mo. The composites with 10 vol% Mo are hardly oxidized. The Mo/alumina composites with the composition of Mo not exceeding 16 vol% may provide a reasonable resistance to oxidation up to 950°C in air.
Type
journal article