Oxidation behavior of a Mo (Si, Al)(2)-based composite at 300-1000 degrees C
Journal article, 2010
The oxidation behavior of a Mo (Si,Al)(2)-based composite of Mo(Si,Al)(2), Al2O3 and Mo-5(Si,Al)(3) (Kanthal Super ER) in synthetic air was investigated. The samples were oxidized isothermally for up to 72 h at 300-1000 degrees C using a thermobalance. The microstructure was analyzed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Auger Electron Spectroscopy (AES) depth profiling. Broad ion beam milling (BIB) was used to prepare cross-sections. Oxidation behavior depended strongly on the composition of the substrate which consisted of a Mo(Si,Al)(2) matrix and the minority phases Mo-5(Si,Al)(3) and Al2O3. At 300-500 degrees C the mass gains were small with parabolic kinetics, oxidation resulting in a mixture of oxides that reflects the substrate composition. At 600 and 700 degrees C the oxide scale is thin and protective and depleted in molybdenum, a mass loss occurring due to MoO3 vaporization. At 1000 degrees C a protective alpha-alumina scale forms.
HIGH-TEMPERATURE OXIDATION
FILMS
Electron microscopy
Oxidation
AL
RANGE
MOSI2-BASED COMPOSITE
Multiphase intermetallics
RESISTANCE
ALLOYS
SILICIDES
various
773 K
MOSI2
Spectroscopic methods
Molybdenum silicides
scanning
Author
Linda Ingemarsson
Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry
Mats Halvarsson
Chalmers, Applied Physics, Microscopy and Microanalysis
Josefin Hall
Hogskolan Dalarna
Torbjörn Jonsson
Chalmers, Applied Physics, Microscopy and Microanalysis
Kristina M Hellström
Chalmers University of Technology
Lars-Gunnar Johansson
Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry
Jan-Erik Svensson
Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry
Intermetallics
0966-9795 (ISSN)
Vol. 18 4 633-640Subject Categories (SSIF 2011)
Materials Engineering
DOI
10.1016/j.intermet.2009.10.019