Anti-sintering behavior and combustion process of aluminum nano particles coated with PTFE:A molecular dynamics study

作     者：Jun-peng Liu Hao-rui Zhang Qi-Long Yan Jun-peng Liu;Hao-rui Zhang;Qi-Long Yan

作者机构：Science and Technology on CombustionInternal Flow and Thermostructure LaboratoryNorthwestern Polytechnical UniversityXi'an 710071China 

出 版 物：《Defence Technology（防务技术）》 (Defence Technology)

年 卷 期：2023年第24卷第6期

页      面：46-57页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the fellowship of China Postdoctoral Science Foundation(Grant No.2021TQ0267) 

主　　题：Aluminum nanoparticle Sintering Combustion Molecular dynamics simulation 

摘      要：The characteristic of easy sintering of aluminum nanoparticle(ANP)limits its application in solid *** ANP with fluoropolymer could effectively improve its combustion *** find out how the coating layer inhibits sintering and promotes complete combustion of particles from an atomic view,a comparative study has been done for bare ANP and PTFE coated ANP by using reactive molecular dynamics *** sintering process is quantified by shrinkage ratio and gyration *** results show that,at the same heating rate and combustion temperatures,bare ANPs are sintered together after the temperature exceeds the melting point of aluminum but the decomposition of PTFE coating layer pushes particles away and increases reaction surface area by producing small Al-F *** sintering of ANPs which are heated in PTFE is alleviated compared with particles heated in oxygen,but particles still sinter together due to the lack of intimate contact between PTFE and alumina *** effect of temperature on the combustion of PTFE coated ANPs is also studied from 1000 to3500 *** number density analysis shows the particles will not be sintered at any *** fluoride prefers diffusing to the external space and the remained particles are mainly composed of Al,C and *** ignition simulations are performed by adopting micro canonical *** the expansion of aluminum core and the melting of alumina shell,bare ANPs are sintered into a liquid particle *** PTFE coated ANPs,the volatilization of gaseous aluminum fluoride products continually endows particles opposite momentum.