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: Z00012

Bibliographic Information

Reference:
"Molten Salt Corrosion of SiC: Pitting Mechanism," N.S. Jacobson and J.L. Smialek, NASA TM-87143, pp. 1-16 (1985), published by National Aeronautics and Space Administration.
Language: English
Notes: NASA Technical Memorandum

General Materials Processing Notes

SCD Citation Number: Z00012
"The starting material was a commercially available sintered α-SiC (Carborundum Co., Niagara Falls, NY) ... This material contains approximately 3 % free carbon, in the form of inclusions a few (micrometers) in diameter."

Measurement Methods

SCD Citation Number: Z00012
Four-point bend test
The authors indicated that four-point bend tests were conducted. "Specimens were coated with Na2CO3 or Na2SO4 (in the amount of 2.5 mg/cm2) and placed in a furnace at 1000 °C (for 48 hours) ... samples (were) ground to 15 µm finish before strength test. ... the reaction occurs primarily in the first 5 h. Corrosion products consist of both SiO2 and Na2O·x(SiO2)." No additional measurement details were noted.

Index of Materials and Properties

SCD Citation Number: Z00012
Material Number 1: SiC

Material Specification and Properties for SiC

Material number 1 of 1
in SCD Citation Number: Z00012
Chemical Class: Carbide
Chemical Family: Si-C
Formula: SiC
Informal Name: silicon carbide
Structure Type: Polycrystalline
Manufacturer: Carborundum Company
Process: Sintering

SiC

Material number 1 of 1
in SCD Citation Number: Z00012
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 1
in SCD Citation Number: Z00012
Flexural Strength
Temperature
 
( °C )
Environment
 
 
Flexural
Strength
( MPa )
1000 air 400 ± 60
1000 Na2SO4/SO3 205 ± 70
1000 Na2CO3/CO2 350 ± 60
1000 Na2SO4/air 245 ± 50

Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria
Cautions:
"In summary, thin salt films of Na2CO3 and Na2SO4 cause severe corrosion pitting of sintered α-SiC at 1000°C. These corrosion pits can act as fracture origins and thus are responsible for corrosion attack strength decreases in this material after corrosion." Digitized data were obtained from Figure 2 of the paper.