Abstract
High purity alumina particles were sonicated in distilled water at 20 kHz. Ultrasonic fragmentation of the alumina particles produced a fine particle fraction, which was less than 1 μm in diameter. This fraction became more pronounced with increased duration and applied power. Particle fragmentation was observed to increase slightly with large increases in slurry density, indicating that the formation and collapse of cavitation bubbles were relatively unaffected by the particulate loading levels. Of great importance, the sonified powders exhibited an exotherm consistent with lattice strain energy release, thereby potentially providing an additional driving force for densification during sintering.
| Original language | English |
|---|---|
| Pages (from-to) | 246-250 |
| Number of pages | 5 |
| Journal | Materials Letters |
| Volume | 42 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 2000 |
Funding
The author would like to acknowledge W.D. Porter for calorimeter operation and subsequent analysis and for D.L Barker for operation of the particle size analyzer. Earlier drafts of this manuscript benefited from the review and comments of John Thomas and Jim Conklin. This work was performed by the Oak Ridge National Laboratory, managed by Lockheed Martin Energy Research for the U.S. Department of Energy under contract DE-AC05-96OR22464.