Study on combustion characteristics of nano-aluminum in different gas atmospheres and environment temperatures

Abstract

Aluminum was extensively used in aerospace and other industries. It is a clean fuel with a high energy density that is simple to store and transport. However, the presence of oxide caps on the surface impedes the combustion of aluminum powder. The combustion process of nano-aluminum in different atmospheres and temperatures was studied in this paper using thermogravimetric analysis and a combustion experiment platform. It was discovered that there is no discernible difference in the combustion process of nAl in the air and CO2 atmospheres under the temperature programmed condition. The combustion process was divided into three stages at the time, with the oxidation process concentrating primarily in the second and third stages. The activation energy showed a change law of first rising, then falling, and then rising at various stages. It was discovered that the combustion process under 20% oxygen concentration was similar to that under CO2 atmosphere by comparing the combustion experiments under different oxygen concentrations and CO2 atmosphere. The greater the concentration of oxygen, the better the combustion effect. The ignition delay time was greatly reduced as the ambient temperature increased from 900 °C to 1000 °C. 900 °C can be regarded as the critical value of nano-aluminum combustion in two gas atmospheres. The combustion product was detected using XRD, and the content of α-Al2O3 increased with increasing temperature.