NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Hot Isostatic Pressing of TiB2-ZrO2(2 Mol % Y2O3) Composite Powders," Y. Muraoka, M. Yoshinaka, K. Hirota, and O. Yamaguchi, Materials Research Bulletin, Vol. 31 [7], pp. 787-792 (1996), published by Elsevier Science Ltd..Language: English
"Powders of ZrO2 containing 2 mol% Y2O2 (Sumitomo Osaka Cement Co., Ltd.) and TiB2 (Japan New Metals Co., Ltd.) were used as starting materials. The former was of high purity and had an average particle size of 0.023 µm. The average particle size of the latter was 1.75 µm. ... powders... were mixed for 20 h by wet ball milling with zirconia balls and ethanol in a polyethylene pot and then dried at 80 °C under pressure. Densification was performed by hot isostatic pressing (HIPing) under argon gas as the pressure transmitting medium. Before HIPing, the mixed powders without calcining were pressed into pellets at 196 MPa and then cold isostatically pressed at 392 MPa. The green compacts, covered with boron nitride powders, were sealed in a Pyrex glass tube under vacuum. HIPing conditions were as follows: heating rate of 400 °C/h; increasing pressure rate of = 180 MPa/h above 800 °C; and sintering for 2 h at 1500 °C under 196 MPa."
"Bulk densities, after lapping with a diamond powder, were measured by the Archimedes method."Three-point bend test
"Test samples (3 mm x 3 mm x 20 mm) for mechanical measurements were cut from the composites with a diamond saw; then they were lapped with a diamond powder (nominal size 1 µm to 2 µm). ... Three-point bending strength was measured with a 16 mm span and a crosshead speed of 0.5 mm/min."Vickers indentation
The authors cite K. Niihara et al., J. Am. Ceram. Soc., Vol. 67, C-13 (1984), and summarize the procedure as follows. "... fracture toughness (KIc) measurements were made by the microindentation technique with a 300 N load.
| Mole Fraction of TiB2 ( % ) |
Mole Fraction of ZrO2 (2Y) ( % ) |
Relative Density ( % ) |
Density ( g cm-3 ) |
|---|---|---|---|
| 100 | 0 | 97.6 | 4.41 |
| 90 | 10 | 98.1 | 4.61 |
| 80 | 20 | 98.6 | 4.79 |
| 70 | 30 | 98.4 | 4.93 |
| 60 | 40 | 96.4 | 4.97 |
| 50 | 50 | 94.1 | 4.98 |
| Mole Fraction of ZrO2 (2Y) ( % ) |
Flexural Strength ( MPa ) |
|---|---|
| 0 | 654 |
| 10 | 806 |
| 20 | 912 |
| 30 | 682 |
| 40 | 552 |
| 50 | 478 |
Data were digitized from Fig. 3 of the reference.
| Mole Fraction of ZrO2 (2Y) ( % ) |
Fracture Toughness ( MPa m1/2 ) |
|---|---|
| 0 | 3.7 |
| 10 | 5.8 |
| 20 | 7.2 |
| 30 | 11.3 |
| 40 | 7.0 |
| 50 | 6.0 |
Data were digitized from Fig. 3 of the reference.