Stability of molybdenum disilicide in combustion gas environments

Journal Article · Sun May 01 04:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb05388.x· OSTI ID:7114776

Lin, W Y; Hsu, J Y; Speyer, R F ^[1]

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1. Alfred Univ., NY (United States). School of Ceramic Engineering and Sciences

The stability of MoSi[sub 2] in combustion gas at 1,370[degree] and 1,600 C was evaluated using SOLGASMIX-PV thermodynamic modeling, periodic weight measurements, and characterization via XRD, SEM, EDS, and image analysis. Passive oxidation occurred at both temperatures. During an initial stage of exposure, specimen surfaces oxidized to form MoO[sub 3(g)] and amorphous SiO[sub 2] via reduction of CO[sub 2] and H[sub 2]O. After a short time (<6.5 min at 1,370 C, <1 min at 1,600 C), the oxidation mechanism switched; Mo[sub 5]Si[sub 3] and amorphous SiO[sub 2] formed as oxidation products. The first mechanism resulted in the formation of 46.1 vol% at 1,370 C and 42.6 vol% at 1,600 C of the amorphous silica surface coating. The attainment of a near-terminal weight gain implied silica formation was limited by H[sub 2]O and CO[sub 2] diffusion through the silica coating.

• OSTI ID: 7114776
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:5; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360205* -- Ceramics
Cermets
&amp; Refractories-- Corrosion &amp; Erosion
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
COMBUSTION PRODUCTS
CORROSION PRODUCTS
CORROSIVE EFFECTS
DATA
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
HYDROGEN COMPOUNDS
INFORMATION
MICROSCOPY
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
MOLYBDENUM SILICIDES
NATURAL GAS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SILICIDES
SILICON COMPOUNDS
SILICON OXIDES
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TRANSITION ELEMENT COMPOUNDS
WATER
X-RAY DIFFRACTION