Aluminum Acceleration and Reaction Characteristics for Aluminized CL‐20‐Based Mixed Explosives

Abstract

The effects of aluminum mass content and particle size in CL‐20‐based aluminized explosives were investigated with a small‐scale confined plate push test. The confinement strength of the detonation products was enhanced to twice that of cylinder tests to accelerate the aluminum particle reaction. An all‐fiber displacement interferometer system for any reflector was used to continuously measure the plate velocity over time. A series of aluminized explosives containing various aluminum particle masses and sizes were tested, as well as explosives containing LiF instead of aluminum. Numerical simulations of explosive detonation and metal plate acceleration were performed, where parameters for the equation of state of the detonation products were calibrated by comparing the results with experiment. The results indicated that most of the aluminum particles (including 200‐nm diameter particles) reacted with the detonation products after the Chapman‐Jouguet point. Moreover, the released energy from the reaction could further accelerate the metal plate and increase the acceleration time, although the initial plate velocity was reduced. The start reaction times of small particles were earlier than that of larger particles. Specifically, 2‐50‐μm aluminum particles start to react when the volume of detonation products expanded to 1.24 times the initial volume, while the 200‐nm particles start to react at 1.07 times the initial volume, with a significantly higher reaction rate. The reaction rates decreased with increasing mass fraction of reacted aluminum and a decrease in pressure.

Study on the cylinder test of aluminized explosives with different content of Al powder

“…It is demonstrated that the energy released by the reaction of Al powder can lead to a significant increment in the energy density because the energy released by the complete Al oxidation is about 30 MJ/kg in comparison with 5-6 MJ/kg released by the ideal condense explosives. [3][4] The accelerating ability of the aluminized explosives is mainly evaluated by metal plate tests [5][6][7][8] , cylinder tests [9][10][11] , and underwater explosion tests [12] . Previous researchers have concluded that the accelerating ability is related to the explosive components, the size of Al powder, the content of Al powder, the mass fraction of oxidizing gas, the temperature of detonation zone and the constraint conditions et al Manner et al [11] carried out copper cylinder tests on explosives based on cyclotetramethylenetetranitramine (HMX), and the size of Al or lithium fluoride (LiF) powder is 3.2 μm.…”

Numerical Simulation of Detonation and Brisance Performance of Aluminized HMX Using Density‐Adaptive SPH

“…Manner et al [2] conducted a series of cylinder tests and plate-pushing experiments to improve the understanding of how Al contributes in the detonation of non-ideal explosive mixtures, which indicates that a significant portion of Al particles reacted after the CÀ J plane, and continue to release energy at later times. Liu et al [3] investigated the effects of mass fraction of Al and particle size in CL-20-based explosive on the metal acceleration and reaction characteristics by using a smallscale confined plate push test, which shows that the Al particles mainly reacted with the detonation products after the CÀ J point, and the released energy was used to accelerate the metal. Liu et al [4] studied the effects of nano-sized Al particles on detonation characteristics, detonation reaction zone, and metal acceleration for RDX-based aluminized explosives through a variety of experiments such as the detonation pressure test and the detonation velocity test.…”

The Effect of Microsized Aluminum Powder on Thermal Decomposition of HNIW (CL-20)

“…erefore, aluminized explosive has been widely used in military and industrial fields and also become a research hotspot. For a long time, the detonation of aluminized explosives, including the theme of secondary reaction theory, calculation of detonation parameters, and equations of state of detonation products, has been discussed in most of the literatures [1][2][3][4][5][6]. However, in recent years, there have been more and more studies on the thermal decomposition of aluminized explosives on the perspective of thermal safety.…”