Nano Aluminum Powders Oxidation in CO_2 and O_2 Environments

摘要

An experimental study of oxidation of nano aluminum (Al) powders in CO_2 and O_2 is described. The oxidation is studied using thermogravimetric (TG) measurements from room temperature to 1500°C. Partially oxidized samples are recovered and their compositions are analyzed using X-ray diffraction. The oxidation product morphology was examined using SEM. Dimensional properties of aluminum particles have a significant influence on the oxidation processes. The nano aluminum reaction onset temperature was much lower than micro aluminum. Distinctly different oxidation properties of nano aluminum powders were shown between CO_2 and O_2. Nano aluminum powders could ignite in O_2 at fairly low temperatures around 530 °C. However ignition for Nano aluminum powders in CO_2 didn't appeared below 1500 °C. There was a weight loss in the TG curves at around 1200 °C for nano Al-CO_2 system. It was thought that small amount carbon formed in the oxidation process. The XRD showed that both the nano aluminum oxidation products were α-Al_2O_3 in CO_2 and O_2.