Reaction mechanism of micron-sized aluminum powders in O2 and CO2 gradually heated environment

Abstract

The behavior of aluminum powders in specific oxidized environment is different from each other obviously. Thermal behaviors of micron-sized aluminum powders in different oxygenated and gradually heating environments were discussed in order to find out the oxidation mechanism. Particular attention is paid to the reaction mechanism of oxygen and carbon dioxide atmosphere. Thermogravimetric analysis and related characterization methods are used and the results demonstrated that under the certain condition, reaction process of micron-sized aluminum powders can be divided into four stages. General routes for the oxidation of micron-sized aluminum in general heating system are the same, however, itis different among the extent of reaction at the third stage in different kinds of oxidizing gas atmospheres. Gas phased products were detected during the main reaction stage under carbon dioxide by combining thermal analysis and mass spectrometry which contributes to the rupture of alumina shell and further reaction of micron-sized aluminum powders. Consequently, rapider and more complete reaction process was achieved. The increasing thickness of original alumina shell can restrict the reaction rate of aluminum powders harder at the same time.