NIST Structural Ceramics Database (SCD) Database

NIST Standard Reference Database 30

Last Update to Data Content: 2002

DOI: http://dx.doi.org/10.18434/T4F30D


SCD Citation Number: Z00040

Bibliographic Information

Reference:
"Fundamental Studies of Corrosion of Nonoxide Structural Ceramics," R.E. Tressler and K.E. Spear, Projects Within the Center for Advanced Materials, pp. 125-143 (1990), edited by J.R. Hellmann and B.K. Kennedy, published by Center for Advanced Materials, Pennsylvania State University.
Language: English
Notes: Document Number CAM-8904, GRI-90/0024

General Materials Processing Notes

SCD Citation Number: Z00040
Material (1): SiC platelets were grown by Acheson furnace synthesis. The platelets were 99.98 % (mass fraction) SiC in the hexagonal 4H polytype. The trace impurity elements were Ti (0.006 %); V (0.013 %); Fe (0.001 %). Material (2): The CVD Si3N4 was deposited on a graphite substrate. Material (3): Hexoloy SA is a siliconized, sintered, α-silicon carbide containing a mixture of cyrstal polytypes 6H and 15R and the following impurities: Al; B; Fe; Ti; Ca; Mg; V; Cu; Ni; Cr; Mn.

Measurement Methods

SCD Citation Number: Z00040
Double oxidation
Specimens were first oxidized in one atmosphere of molecular oxygen, isotope 16, at 1200 °C {SiC: 180 min for 0 ppm and 50 ppm Na+ ions and 150 min for 1000 ppm implanted Na+ ions; Si3N4: 420 min}. Then, a second oxidation was performed in molecular oxygen, enriched to 20% isotope 18, at 1100 °C {SiC: 30 min; Si3N4: 60 min}. Then, oxygen isotope profiles were measured by secondary ion mass spectrometry using a cesium, isotope 133, primary ion beam with an accelerating voltage of 5.03 kV and a raster of 250 µm.
Oxidation test
The authors cite Z. Zheng et al., J. Electrochem. Soc., Vol. 137(3), 854-858 (1990), and summarize the procedure as follows. Specimens were ground with diamond grinding disks and polished to a finish of 0.1 µm. Specimens were cleaned by successive treatments in trichloroethylene, acetone, dilute 10% HCl acid solution, and buffered HF acid. Specimens were rinsed with dionized water after each of these treatments. Then, specimens were stored in a glass dessicator. Next, specimens were preheated in extra dry oxygen (3 ppm H2O) at 1150 °C in a horizontal fused silica tube furnace heated by molybdenum disilicide heating elements, to produce a layer of SiO2 approximately 300 Å thick. Na+ ions were implanted into the specimens using a multilayer implantation technique with a beam energy from 25 keV to 180 keV. Specimens were oxidized in a horizontal mullite tube furnace heated by molybdenum disilicide heating elements. Specimens were placed on a sintered alpha silicon carbide holder and pushed in and pulled out of the furnace with a quartz pushrod. Temperatures were maintained within 2 °C and measured by Pt/Pt 10% Rh thermocouples. The thickness of the oxide layer was measured using a monochromatic ellipsometer using a helium-neon laser with a wavelength of 6328 Å. Parabolic oxidation rates were calculated from oxide thickness versus oxidation time data. Activation energy was computed from measurements of parabolic oxidation rates at 1100 °C, 1200 °C, and 1300 °C.

Index of Materials and Properties (Click on a selected Material Number to expand material properties menu)

SCD Citation Number: Z00040

Material Specification and Properties for SiC

Material number 1 of 3
in SCD Citation Number: Z00040
Chemical Class: Carbide
Chemical Family: Si-C
Formula: SiC
Informal Name: silicon carbide
Manufacturer: In-House
Production Form: Plate
Process: Crystal Growth

SiC

Material number 1 of 3
in SCD Citation Number: Z00040
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
1 Si
1 C
Measurement Method: Reported Formula
Evaluation Status: Unevaluated

SiC

Material number 1 of 3
in SCD Citation Number: Z00040
Corrosion Activtn Energy
Temperature
 
( °C )
Na+ implant
 
( ppm )
Corrosion
Activtn Energy
( kJ/mol )
1200 0 123
1200 50 144
1200 1000 128
Measurement Method: Oxidation test
Evaluation Status: Evaluated by acceptance criteria

SiC

Material number 1 of 3
in SCD Citation Number: Z00040
Diffusion Coefficient
Temperature
 
( °C )
Na+ implant
 
( ppm )
Diffusing
Species
 
Diffusion
Coefficient
( mm2 h-1 )
1100 0 O2 -8.19
1200 0 O2 -7.85
1300 0 O2 -7.62
1100 50 O2 -8.05
1200 50 O2 -7.64
1300 50 O2 -7.35
1100 1000 O2 -7.92
1200 1000 O2 -7.59
1300 1000 O2 -7.30
Measurement Method: Double oxidation
Evaluation Status: Evaluated by acceptance criteria

Material Specification and Properties for Si3N4

Material number 2 of 3
in SCD Citation Number: Z00040
Chemical Class: Nitride
Chemical Family: Si-N
Formula: Si3N4
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: In-House
Process: Chemical Vapor Deposition

Si3N4

Material number 2 of 3
in SCD Citation Number: Z00040
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
3 Si
4 N
Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4

Material number 2 of 3
in SCD Citation Number: Z00040
Corrosion Activtn Energy
Temperature
 
( °C )
Na+ implant
 
( ppm )
Corrosion
Activtn Energy
( kJ/mol )
1200 0 460
1200 50 404
1200 1000 384
Measurement Method: Oxidation test
Evaluation Status: Evaluated by acceptance criteria

Material Specification and Properties for SiC

Material number 3 of 3
in SCD Citation Number: Z00040
Chemical Class: Carbide
Chemical Family: Si-C
Formula: SiC
Informal Name: silicon carbide
Structure Type: Polycrystalline
Manufacturer: Sohio Engineered Materials Co.
Commercial Name: Hexoloy SA
Production Form: Tube
Process: Sintering

SiC

Material number 3 of 3
in SCD Citation Number: Z00040
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
1 Si
1 C
Measurement Method: Reported Formula
Evaluation Status: Unevaluated

SiC

Material number 3 of 3
in SCD Citation Number: Z00040
Impurities
Mass Fraction
of Impurity
( % )
Impurity
 
( no unit )
3.00 Al
0.04 B
0.01 Fe
0.01 Ti
0.04 Ca
0.01 Mg
0.005 V
0.01 Cu
0.003 Ni
0.02 Cr
0.005 Mn
Measurement Method: Reported Formula
Evaluation Status: Unevaluated

SiC

Material number 3 of 3
in SCD Citation Number: Z00040
Corrosion Activtn Energy
Temperature
 
( °C )
Na+ implant
 
( ppm )
Corrosion
Activtn Energy
( kJ/mol )
1200 -- 123
Measurement Method: Oxidation test
Evaluation Status: Evaluated by acceptance criteria

SiC

Material number 3 of 3
in SCD Citation Number: Z00040
Density (mass)
Density
 
( g cm-3 )
3.16
Measurement Method: Unknown
Evaluation Status: Unevaluated
Cautions:
No measurement details were noted.