NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Fracture Toughness of Ceramics using the SEVNB Method: Preliminary Results," J. Kubler, Ceramic Engineering and Science Proceedings, Vol. 18 [4], pp. 155-162 (1997), published by American Ceramic Society.Language: English
"Eight advaned ceramics... were tested:... hot pressed silicon nitride (NC-132),... hot-isostatic pressed silicon nitride (HSN),... sintered and post-hipped, 3 mole% yttria-stabilised tetragonal zirconia (Y-TZP) with an average grain size of 0.45 µm,... silicon carbide whisker (20 vol%) reinforced silicon nitride (CMC),... alumina (Al2O3) with an average grain size of 16 µm,... sintered silicon carbide (SSiC) with an average grain size of 7 µm,... hot pressed silicon nitride (HPSN), and... magnesium partially stabilised zirconia (Mg-PSZ) with an average grain size of 60 µm..."
No measurement information was noted.> Single-edge V-notched beam
"Large standard 3 mm x 4 mm x 45 mm specimens with four point spans of S1 = 40 mm and S2 = 20 mm were used for (most) flexure testing. ... small specimens 2 mm x 2.5 mm x (22 to 25) mm were tested with spans of 20 mm and 10 mm, respectively. All specimens were tested on their 3 mm and 2 mm wide faces for the large and small specimens, respectively. At least 5 specimens were tested from each ceramic. Before testing, a straight notch was introduced into the centre of the specimens tensile surface. The total depth of the notches was between 0.8 mm and 1.2 mm for the large specimen and between 0.5 mm and 0.75 mm for the small specimen. The notches were produced either by hand or machining. ... By Hand:... A straight notch was cut with a 200 µm wide diamond wheel to a depth of about 50% of the final depth. ... A second notch was polished into the first one using the slot as a guide. The polishing was done by hand with a razor blade sprinkled with a 4 µm diamond paste. By Machine: A straight notch was polished with the machine and razor blade sprinkled with a 4 µm diamond paste. ... After cleaning the specimen(s), 10% of the final notch depth was polished using a new razor blade sprinkled with a 1 µm diamond paste."
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 3 x 4 | machine | 4.36 ± 0.08 |
| 2 x 2.5 | machine | 4.36 ± 0.08 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 3 x 4 | hand | 5.10 ± 0.09 |
| 2 x 2.5 | machine | 4.97 ± 0.12 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 3 x 4 | hand | 5.48 ± 0.30 |
| 2 x 2.25 | machine | 4.69 ± 0.09 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 3 x 4 | hand | 6.38 ± 0.10 |
| 3 x 4 | hand | 6.31 ± 0.04 |
| 2 x 2.5 | machine | 6.22 ± 0.10 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 2 x 2.5 | machine | 3.03 ± 0.11 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 3 x 4 | hand | 5.07 ± 0.18 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 3 x 4 | hand | 2.62 ± 0.10 |
| Specimen Size ( mm x mm ) |
Notch Polishing |
Fracture Toughness ( MPa m1/2 ) |
|---|---|---|
| 2 x 2.5 | machine | 7.08 ± 0.17 |