Aluminum particles with nano-size defects in their alumina shells and their thermal oxidation properties

Micron-size aluminum particles with the nano-size defects in the alumina shells, called as treated Al, were prepared through a facile method. Powder particle morphologies and compositions were characterized, and results showed that the treated Al maintained its original spherical shapes and aluminum content, and there existed the nano-size etched pits and pores in its Al₂O₃ shell. The thermal oxidation properties of the treated Al and the as-received Al particles in air were tested by differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). It was observed that the thermal oxidation activity of the treated Al was much higher than that of the as-received Al and the treated Al was nearly completely oxidized in the air.