NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Effect of Creep Damage on the Tensile Creep Behavior of a Siliconized Silicon Carbide," D.F. Carroll and R.E. Tressler, Journal of the American Ceramic Society, Vol. 72 [1], pp. 49-53 (1989), published by American Ceramic Society.Language: English
"The siliconized silicon carbide examined in this study contained approximately 33.7 % to 35.7 % (volume fraction) free silicon metal with the remainder of the material composed of silicon carbide grains, 4 µm to 6 µm in size."
Specimens were cut from rectangular blanks, approximately 76.2 mm x 12.7 mm x 2.5 mm, with a 320-grit finish, using wire electrodischarge machining. The final shape was a flat "dog-bone" with two target arms and a gauge length of 17.5 mm. Two holes, machined directly on the specimen's centerline and machined to uniform smoothness, were used to pin the specimen to the loading system. The tensile test specimen was attached to two siliconized silicon carbide grips with α-silicon carbide pins. The pin and grip assembly was located inside the furnace with the grips extending outside the furnace to attach to the loading system. Loads were applied by hanging weights on a loading platform design to minimize the bending moment. Creep elongation was measured by an optical extensometer with a resolution of 1µm at 1100°C in air.
| Amount of Element ( formula units ) |
Element ( no unit ) |
|---|---|
| 1 | Si |
| 1 | C |
| Temperature ( °C ) |
Applied Stress ( MPa ) |
Creep Activatn Energy ( kJ mol-1 ) |
|---|---|---|
| 1100-1200 | 103 | 175 |
| 1100-1200 | 137 | 210 |
| 1100-1200 | 172 | 350 |
| Temperature ( °C ) |
Applied Stress ( MPa ) |
Creep Rate Exponent ( no unit ) |
|---|---|---|
| 1100 | 103 | 4 |
| 1100 | 120 | 4 |
| 1100 | 137 | 4 |
| 1100 | 137 | 10 |
| 1100 | 160 | 10 |
| 1100 | 170 | 10 |
The creep exponent was 4 below the threshold stress for creep damage, and 10 above the threshold.