NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Mechanical Properties of Hot-Pressed Silicon Nitride with Different Grain Structures," G. Himsolt, H. Knoch, H. Heubner, and F.W. Kleinlein, Journal of the American Ceramic Society, Vol. 62 [1], pp. 29-32 (1979), published by American Ceramic Society.Language: English
"A Si3N4 powder (H. C. Stark, Goslar) (6 % (mass fraction) β phase, average grain size 0.3 µm) was mixed with 5 % MgO in a Teflon jar with agate balls under isopropanol and vacuum hot pressed at 1973 K and 2053 K for 10 min, 30 min, 50 min, 70 min, and 90 min under a pressure of 31 MN/m2. The hot pressed disks (75 mm in diameter and 5 mm to 6 mm high) were diamond ground and cut into bars (3.5 mm by 4.5 mm by 45 mm)."
"The elastic constants were determined by a resonance frequency technique." No additional measurement details were noted.Four-point bend test
The authors cite J. Nakayama, J. Am. Ceram. Soc., Vol. 48 (11), 583-587 (1965), and summarize the procedure as follows. "...samples were loaded to fracture in 4-point bending parallel to the hot pressing direction. The outer span length was 40 mm and the inner span length 20 mm; eight samples were broken to obtain each data point. The specific work of fracture was evaluated on bend specimens from the area under the load deflection curve. ... In these tests the span lengths 43 mm and 10 mm. The KIc was tested on two specimens of each grade, which contained sharp and natural cracks... But in this case, the test is stopped when the crack extends through the whole thickness of the specimen. These precracked samples were put on smaller span lengths (28 mm and 10 mm) and loaded at a higher strain rate to obtain catastrophic failure."
| Amount of Element ( formula units ) |
Element ( no unit ) |
|---|---|
| 3 | Si |
| 4 | N |
| Sintering Aid Mass Fraction ( % ) |
Sintering Aid ( no unit ) |
|---|---|
| 5 | MgO |
| Measurement Temperature ( °C ) |
Hot Pressing Time ( min ) |
Hot Pressing Temperature ( K ) |
Elastic Modulus ( GPa ) |
|---|---|---|---|
| 22 | 10 | 1973 | 317.5 |
| 22 | 50 | 1973 | 311.1 |
| 22 | 90 | 1973 | 302.8 |
| 22 | 90 | 2053 | 309.6 |
| Measurement Temperature ( °C ) |
Hot Pressing Time ( min ) |
Hot Pressing Temperature ( K ) |
Flexural Strength ( MPa ) |
|---|---|---|---|
| 22 | 10 | 2053 | 478 |
| 22 | 30 | 2053 | 675 |
| 22 | 50 | 2053 | 706 |
| 22 | 70 | 2053 | 629 |
| 22 | 90 | 2053 | 586 |
Digitized data were obtained from Figure 1 of the paper.
| Measurement Temperature ( °C ) |
Hot Pressing Time ( min ) |
Hot Pressing Temperature ( K ) |
Fracture Energy ( J m-2 ) |
|---|---|---|---|
| 22 | 10 | 1973 | 16.5 |
| 22 | 50 | 1973 | 30.4 |
| 22 | 90 | 1973 | 67.8 |
| 22 | 90 | 2053 | 47.4 |
| Measurement Temperature ( °C ) |
Hot Pressing Time ( min ) |
Hot Pressing Temperature ( K ) |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|---|
| 22 | 10 | 1973 | 3.20 |
| 22 | 50 | 1973 | 4.96 |
| 22 | 90 | 1973 | 7.81 |
| 22 | 90 | 2053 | 6.59 |
| Measurement Temperature ( °C ) |
Hot Pressing Time ( min ) |
Hot Pressing Temperature ( K ) |
Poisson's Ratio ( no unit ) |
|---|---|---|---|
| 22 | 10 | 1973 | 0.258 |
| 22 | 50 | 1973 | 0.256 |
| 22 | 90 | 1973 | 0.271 |
| 22 | 90 | 2053 | 0.265 |