Abstract
Oxidation of aluminum nanopowders obtained by electro-exploded wires is studied. Particle size distributions are obtained from transmission electron microscopy (TEM) images. Thermo-gravimetric (TG) experiments are complemented by TEM and XRD studies of partially oxidized particles. Qualitatively, oxidation follows the mechanism developed for coarser aluminum powder and resulting in formation of hollow oxide shells. The TG results are processed to account explicitly for the particle size distribution and spherical shapes, so that oxidation of particles of different sizes is characterized. The apparent activation energy is obtained as a function of the reaction progress using model-free isoconversion processing of experimental data. A complete phenomenological oxidation model is then proposed assuming a spherically symmetric geometry. The oxidation kinetics of aluminum powder is unaffected by particle sizes reduced down to tens of nm. The trends describing changes in both activation energy and pre-exponent of the growing amorphous oxide are useful for prediction ignition delays of aluminum particles. The kinetic trends describing activation energies and pre-exponents in a broader range of the oxide thicknesses are useful for prediction of aging behavior of aluminum powders.
| Original language | English (US) |
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| State | Published - 2016 |
| Event | 2016 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2016 - Princeton, United States Duration: Mar 13 2016 → Mar 16 2016 |
Other
| Other | 2016 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2016 |
|---|---|
| Country/Territory | United States |
| City | Princeton |
| Period | 3/13/16 → 3/16/16 |
All Science Journal Classification (ASJC) codes
- Mechanical Engineering
- Physical and Theoretical Chemistry
- Chemical Engineering(all)