NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Microwave Plasma Sintering of Nanocrystalline Alumina," J. Peng, P. Hong, S. Dai, D. Vollath, and D.V. Szabo, Journal of Materials Science and Technology, Vol. 14, pp. 173-175 (1998), published by Allerton Press, Inc..Language: English
"The nanocrystalline alumina powders were produced by microwave plasma... The reaction was performed in a 50 mm diameter vessel made of quartz, passing a TE01 mode cavity in succession connected to a 0.915 GHz microwave generator. ... The nanocrystalline alumina powders were pressed at 400 MPa into 0.8 cm diameter discs. The single mode (TE113) tunable cylindrical resonant cavity with 2.45 GHz was used as the microwave plasma sintering apparatus."
"Microhardness was measured on polished surface by the Vickers microhardness tester (Fischerscope H100, Helmut Fischer Ltd. Germany), using loads of 100 mN for 20 s. Typical standard deviation was ±6 GPa for Vickers microhardness. Generally not less than ten different regions were sampled to obtain the average hardness of each specimen."
| Powder Grain Size Range ( nm ) | Relative Density ( % ) | Hardness ( GPa ) |
|---|---|---|
| 4-8 | 78.3 | 12.1 |
| 4-8 | 89.6 | 20.8 |
| 4-8 | 99.2 | 28.4 |
| 50-100 | 69.9 | 5.0 |
| 50-100 | 79.8 | 11.4 |
| 50-100 | 88.7 | 16.3 |
Data were digitized from Fig. 3 of the reference.