Effect of starting particle size on hot-pressing of magnesium oxide powder prepared by vapour-phase oxidation process |
| |
Authors: | K Itatani R Yasuda F Scott Howell A Kishioka |
| |
Affiliation: | (1) Department of Chemistry, Faculty of Science and Engineering, Sophia University, 7-1 Kioi-cho, Chiyoda-ku Tokyo 102, Japan |
| |
Abstract: | Effect of starting particle size on hot-pressing of magnesium oxide (MgO) powder was examined using seven kinds of MgO powders
prepared by a vapour-phase oxidation process; the average primary particle sizes were 11, 25, 32, 44, 57, 107 and 261 nm.
These compressed powders (compacts) were hot-pressed at a temperature between 900 and 1300°C. The densifications of these
compacts during the hot-pressing proceeded via (i) the sintering of primary particles within secondary particles and the rearrangement
of secondary particles/grains (900°C), (ii) the gradual grain growth controlled by the pore migration (900∼1100°C) and (iii)
the rapid grain growth due to the active mass transfer (1300°C); the grain sizes of MgO compacts hot-pressed at and below
1100°C were <1 μm, while those at 1300°C attained 20∼30 μm. The transluscent compact with the relative density of 99.7% could
be obtained when the compressed powder with the average primary particle size of 44 nm was hot-pressed at a temperature as
low as 1100°C for 1 h.
This revised version was published online in November 2006 with corrections to the Cover Date. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|