NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Surface Crack in Flexure (SCF) Measurements of the Fracture Toughness of Advanced Ceramics," R.J. Gettings and G.D. Quinn, Ceramic Engineering and Science Proceedings, Vol. 16 [4], pp. 539-547 (1995), published by American Ceramic Society.Language: English
"Several materials... were selected for this study... Samples of these materials were procured in the form of plates or billets..." NC-435 was prepared as a siliconized SiC. Osram 3120 and 3122 were gas phase sintered.
"... standard sized 4 mm x 3 mm x 50 mm flexure bars (with some exceptions) were machined. These materials were precracked using a Knoop diamond indenter at a load of 5 kg. The diamond was tilted at a 1/2 degree angle relative to the surface so that the resulting precrack would be at a slight angle to the fracture surface. The slight tilt... is a significant aid to fractographic analysis. The indentation and residual stress were removed by polishing off 4.5x the depth of the indentation... Fracture was initiated using standard 20 mm x 40 mm fully-articulating four point flexure fixtures, at a crosshead speed of 0.5 mm/min, in accordance with ASTM C1161. ... To identify the precrack, one broken half (or both as needed) of the specimen was mounted on an SEM stub."Manufacturer's data
"Density... elastic modulus... and Poisson's ratio... are from commercial manufacturers' data or published dynamic (ultrasound or resonance) data."
| Density ( g cm-3 ) |
|---|
| 3.37 |
| Elastic Modulus ( GPa ) |
|---|
| 310 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 6.35 ± 0.10 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.27 |
| Density ( g cm-3 ) |
|---|
| 3.16 |
| Elastic Modulus ( GPa ) |
|---|
| 320 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 5.41 ± 0.24 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.26 |
| Density ( g cm-3 ) |
|---|
| 3.23 |
| Elastic Modulus ( GPa ) |
|---|
| 320 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 5.80 ± 0.23 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.27 |
| Density ( g cm-3 ) |
|---|
| 3.23 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 5.36 ± 0.62 |
| Density ( g cm-3 ) |
|---|
| 3.22 |
| Elastic Modulus ( GPa ) |
|---|
| 310 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 5.22 ± 0.18 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.26 |
| Density ( g cm-3 ) |
|---|
| 2.53 |
| Elastic Modulus ( GPa ) |
|---|
| 180 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 1.65 ± 0.09 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.22 |
| Density ( g cm-3 ) |
|---|
| 3.36 |
| Elastic Modulus ( GPa ) |
|---|
| 460 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 4.37 ± 0.38 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.17 |
| Density ( g cm-3 ) |
|---|
| 2.99 |
| Elastic Modulus ( GPa ) |
|---|
| 350 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 3.70 ± 0.27 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.18 |
| Density ( g cm-3 ) |
|---|
| 3.96 |
| Elastic Modulus ( GPa ) |
|---|
| 386 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 3.39 ± 0.09 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.21 |
| Density ( g cm-3 ) |
|---|
| 2.48 |
| Elastic Modulus ( GPa ) |
|---|
| 455 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 3.08 ± 0.07 |
| Density ( g cm-3 ) |
|---|
| 4.64 |
| Elastic Modulus ( GPa ) |
|---|
| 542 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 5.20 ± 0.41 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.12 |
| Density ( g cm-3 ) |
|---|
| 4.67 |
| Elastic Modulus ( GPa ) |
|---|
| 581 |
| Fracture Toughness ( MPa m1/2 ) |
|---|
| 5.36 ± 0.50 |
| Poisson's Ratio ( no unit ) |
|---|
| 0.12 |