Combustion mechanism of fluorinated organic compound-modified nano-aluminum composite particles: Towards experimental and theoretical investigations
Siyi ZHANG, Yunlan Sun, Jiuyu CHEN, Tao Sun, Baozhong Zhu
Abstract
Fluorinated Organic Compounds (FOCs) are commonly used as modifiers for Aluminum (Al) powder to improve its ignition, combustion, and agglomeration characteristics. However, the effects of FOCs on combustion and inhibition mechanisms of agglomeration of Al powder are not well understood. In this paper, based on the experimental study of Fluorinated Graphite (FG)-modified Al matrix composite particles, the combustion and aggregation inhibition mechanisms of FOCs on Al particles were studied by the quantum chemical calculation at B3LYP/6-311+G(d,P) and G3//B3LYP/6-311+G(d,p) levels. The flame behavior and single particle burning behavior of FG-modified samples were compared through ignition experiments, and the characteristic spectra of Al related oxides of different samples in the initial ignition stage were captured. It is found that FG increases the burning intensity of Al composite samples significantly, while it decreases the emission intensity of Al secondary oxides. Quantum chemical calculation results show that the thermal decomposition intermediates of FOCs, namely C 2 F 4 , can react with AlO and Al 2 O, which weakens the characteristic emission intensity of AlO and Al 2 O in the sample, and thus inhibits the formation of Al 2 O 3 in the combustion process . These results contribute to enriching the combustion dynamics model of Al-FOCs reaction system.