TY - JOUR
T1 - The effect of alumina as an interfacial layer on the reactivity of Al/PTFE energetic composites
AU - Liu, Junpeng
AU - Xiong, Kunyu
AU - Zhang, Haorui
AU - Nie, Hongqi
AU - Yan, Qi Long
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2023/5/1
Y1 - 2023/5/1
N2 - The exothermic behaviors of metastable intermixed composites (MICs) composed of aluminum (Al) and fluoropolymer are highly dependent on the interfacial properties. To study the effect of alumina thickness on the reactivity of Al/PTFE composites, the composites with different particle sizes have been prepared and evaluated in terms of thermal reactivity, which has been realized by experiments and molecular dynamic (MD) simulations. The kinetic parameters obtained from thermal analysis experiments are in good agreement with the simulation results. The isothermal MD simulations reveal the initial reaction process of the composite containing nanosized Al can be divided into three zones. The existence of pre-reaction zone is responsible for the lower ignition delay observed for nanosized Al in presence of PTFE. However, the chemisorption dominates the reaction of the bulk alumina, with condensed products readily to aggregating on the surface. Self-diffusion coefficient analysis indicates reducing the thickness of alumina shell by one time will increase the peak diffusion rate of oxidant atoms by 1.6 times. The molten Al atoms crossing through the core-shell interface could reach a heat transfer rate of 150 J/ps, whereas the values for model representing micron composites and bulk alumina are only 51.5 J/ps and 37.0 J/ps, respectively.
AB - The exothermic behaviors of metastable intermixed composites (MICs) composed of aluminum (Al) and fluoropolymer are highly dependent on the interfacial properties. To study the effect of alumina thickness on the reactivity of Al/PTFE composites, the composites with different particle sizes have been prepared and evaluated in terms of thermal reactivity, which has been realized by experiments and molecular dynamic (MD) simulations. The kinetic parameters obtained from thermal analysis experiments are in good agreement with the simulation results. The isothermal MD simulations reveal the initial reaction process of the composite containing nanosized Al can be divided into three zones. The existence of pre-reaction zone is responsible for the lower ignition delay observed for nanosized Al in presence of PTFE. However, the chemisorption dominates the reaction of the bulk alumina, with condensed products readily to aggregating on the surface. Self-diffusion coefficient analysis indicates reducing the thickness of alumina shell by one time will increase the peak diffusion rate of oxidant atoms by 1.6 times. The molten Al atoms crossing through the core-shell interface could reach a heat transfer rate of 150 J/ps, whereas the values for model representing micron composites and bulk alumina are only 51.5 J/ps and 37.0 J/ps, respectively.
KW - Decomposition kinetics
KW - Heat transfer
KW - Isothermal diffusion
KW - Metastable intermixed composites
KW - Molecular dynamics simulation
UR - http://www.scopus.com/inward/record.url?scp=85152106665&partnerID=8YFLogxK
U2 - 10.1016/j.jmrt.2023.03.223
DO - 10.1016/j.jmrt.2023.03.223
M3 - 文章
AN - SCOPUS:85152106665
SN - 2238-7854
VL - 24
SP - 3033
EP - 3047
JO - Journal of Materials Research and Technology
JF - Journal of Materials Research and Technology
ER -