Two-step heating in the formation of nanosized alumina particles by a pulsed wire discharge method

Oxidation phenomena in pulsed wire discharge of Al wires to synthesize nanosized Al2O3 powders were analyzed by using a high-speed infrared thermometer during experiments in atmospheres of Ar and O2. An abrupt increase in temperature caused by the electric heating and a subsequent decrease were observed under all conditions. A second temperature increase, which was considered to be caused by heat from the oxidation of residual metallic Al, was found in the O2 atmosphere, but was not detected in Ar.