NIST Standard Reference Database 30
Last Update to Data Content: 2002
"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
"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."
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.
| Amount of Element ( formula units ) | Element ( no unit ) |
|---|---|
| 1 | Si |
| 1 | C |
| 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 |
"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.