The thermal decomposition process of Composition B by ReaxFF/lg force field
- PDF / 2,167,603 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 85 Downloads / 188 Views
ORIGINAL PAPER
The thermal decomposition process of Composition B by ReaxFF/lg force field Jingwei Meng 1 & Shuhai Zhang 1 & Ruijun Gou 1 & Yahong Chen 1 & Yang Li 1 & Minghua Chen 2 & Zhao Li 3 Received: 25 May 2020 / Accepted: 3 August 2020 / Published online: 21 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Composition B is a melt-cast explosive consisting of mixtures of TNT and RDX. It has many excellent properties, but there are still multiple safety problems when it is used. Therefore, it is of importance to understand the thermal decomposition mechanism of Composition B. In this paper, during the establishment of the supercell model, the mass ratio of TNT to RDX is about 2:3, which accords with the actual proportion of formula of Composition B. Afterward, the thermal decomposition reaction of Composition B is conducted at various temperatures (2000 K, 2500 K, 3000 K, 3500 K, and 4000 K) by using molecular dynamics simulation of ReaxFF/lg. In terms of potential energy (PE) evolution, primary reaction, intermediate product, final product, and clusters, the thermal decomposition mechanism of Composition B is made an analysis. The activation energy of Composition B is 141.8 kJ/mol by fitting the kinetic parameters of the reaction. During the decomposition process of Composition B, the decay rate of RDX is faster than that of TNT, and the decay rates of TNT and RDX is accelerated significantly with the increasing temperature. The higher the temperature, the shorter the time difference between the two to fully decompose. It can be revealed from the result that the initial reaction path of Composition B decomposition is N–NO2 of RDX cleavage to form NO2, followed by the reaction of TNT with NO2 and other molecules. The initial decomposition reaction path of Composition B is the similar at different temperatures. The main products are small molecules (NO2, NO, N2O, H2O, CO2, N2, H2, HNO2, and HNO). Temperature can make a great difference for the structure of clusters. Large clusters in the system will break down into smaller molecules at high temperature. Keywords Composition B . Thermal decomposition . Reaxff/lg . Molecular dynamic
Introduction Composition B has been widely used for ammunition loading because of its excellent properties, such as high energy, good safety, and moderate price. It is a high-energy mixed explosive with TNT and RDX being its main components, and its power and detonation velocity are much higher than that of TNT [1, 2]. Composite explosives have been used in weapons and equipment in many countries since the 1990s. Composite * Shuhai Zhang [email protected] 1
School of Environment and Safety Engineering, North University of China, Xueyuan Rd.3, Taiyuan 030051, People’s Republic of China
2
New Technology Applications Institute of Shijiazhuang, Shijiazhuang 050000, People’s Republic of China
3
Beijing Institute of Special Mechatronics, Beijing 100012, People’s Republic of China
explosives can make up the insufficiency in variety and raw material s
Data Loading...
