Sintering process of Y2O3 and Al2O3-doped Si3N4 |
| |
Authors: | Osami Abe |
| |
Affiliation: | (1) Government Industrial Research Institute, Nagoya 1-1 Hirate-cho, Kita-ku, 462 Nagoya, Japan |
| |
Abstract: | The sintering process of Y2O3- and Al2O3-doped Si3N4 has been investigated by dilatometry and microstructural observations. The densification progressed through three processes. The bulk density increased to 85% theoretical without the formation of -Si3N4 in the initial process. The densification once terminated after the second process. The / transformation of Si3N4 and the related formation of prismatic grains reduced the densification rate in the second process, although the grain size and the aspect ratio were very small. The final process was the densification of -Si3N4, where the fibrous grains grew remarkably. The kinetic order for the densification of -Si3N4 indicated a diffusion-rate controlling mechanism with the activation energy of 244 kJ mol–1 (<1450 ° C) and 193 kJ mol–1 (>1450 ° C). The influence of heating rate on the grain growth was characterized by a parameter derived from kinetic parameters. The relationships between grain growth and densification behaviour have also been discussed. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|