聚四氟乙烯包覆铝粉烧结的模拟与分析-《爆破器材》

文章信息/Info

Title:: Simulation and Analysis of the Sintering Process of Aluminum Powder Coated by Teflon

Author(s):: TAO Jun; WANG Xiaofeng; WANG Cailing; HAN Zhongxi; HUANG Yafeng; DIAO Xiaoqiang; Xi’an Modern Chemistry Research Institute (Shaanxi Xi’an, 710065)

摘要:: 为了分析烧结过程对聚四氟乙烯(PTFE)包覆Al粉性能的影响，利用分子动力学手段计算了298 K和678 K时PTFE在Al₂O₃（001）、（010）及（100）晶面6×6晶层的结合能，利用耗散粒子动力学手段模拟了298 K和678 K时Al₂O₃/PTFE在不同时刻的介观状态。计算及模拟结果表明：298 K时，PTFE在Al₂O₃（001）、（010）及（100）晶面的6×6晶层的结合能分别为2 782.67、5 582.97及4 634.32 kJ/mol；678 K时PTFE与Al₂O₃（001）、（010）及（100）晶面的结合能分别是2 835.29、5 537.54及4 608.49 kJ/mol。低温时，PTFE和Al₂O₃混溶性差，两种物质发生明显分相；高温时，PTFE和Al₂O₃混溶性较好，没有发生明显的分相。烧结过程有助于PTFE在Al₂O₃中的扩散，同时还可以提高聚合物与Al₂O₃的混溶性，但对PTFE包覆Al粉的强度影响不大。

Abstract:: In order to analyze the effects of sintering process on the properties of aluminium powder coated by teflon (PTFE), the binding energy of PTFE on the 6×6 crystal layer of Al₂O₃(001), (010) and (100) crystal plane at 298 K and 678 K were calculated by molecular dynamics method, and the mesoscopic state of PTFE-Al₂O₃ at different times at 298 K and 678 K were simulated by dissipative particle dynamics method. Calculation and simulation results show that the binding energy of PTFE on Al₂O₃ (001), (010) and (100) crystal plane at 298 K is 2 782.67, 5 582.97 kJ/mol and 4 634.32kJ/mol, respectively; while at 678 K it is 2 835.29, 5 537.54 kJ/mol and 4 608.49 kJ/mol, respectively. The compatibility of PTFE and Al₂O₃ is poor at low temperature, for which the two substances are separated. At elevated temperature PTFE and Al₂O₃ present better compatibility, without obvious phase separation. The sintering process promotes the diffusion of PTFE in Al₂O₃ and also can increase the miscibility of the polymer and Al₂O₃. However, PTFE has little effect on the strength of coated aluminium powder.