Aluminized Explosives

Abstract

Experimental velocity-diameter D(d) and velocity-density D ( p 1 ) curves are presented for 80/20 TNT-Aluminum (AI), 45/30/25 RDX-TNT-Aluminum (AI), 75/25 Composition B-AI (HBX), and various mixtures of ammonium nitrate and aluminum ranging from pure ammonium nitrate to 6OY0 AN. Also presented are some results with AN-DNT mixtures. Results show that aluminum reacts too rapidly for the energy release as a function of time to be a limiting factor in TNT-AI and RDX-TNT-AI mixtures at diameters above 5 cm., but it reacts relatively slowly in the AN-AI mixtures and the rate of reaction of aluminum (and AN), or the rate of energy release is a limiting factor in this case. The familiar pro erties of the high temperature Al-explosives are here attributed to the thermodynamics of AI-reactions in which the A128(g) /Al~Os(c) ratio is appreciable in the detonation wave but becomes negligible later on during adiabatic expansion. The change of this ratio from a high value in the detonation wave to an ultimate low value gives aluminized explosives low "brisance" but high blast potential. The AN-A1 mixtures were shown to be "non-ideal" (D < D*) over the entire range of conditions studied.Reaction rates in these mixtures are shown to depend on the particle size of both the AN atid the Al. They seem to be controlled by mass transfer which leads to anomalous D(p1) curves each showing a maximum at a relatively low density (1.0 to 1.2 g./cc.). IntroductionAluminized explosives are chayacterized in general by relatively low "brisance" but high (underwater, open air and underground) blast potential. The low relative I' brisance" of aluminized explosives has been attributed in the past to incomplete reaction of A1 a t the " Chapment-Jouguet plane," and the high blast-potential to after-burning of aluminum. Thus early unpublished shaped charge studies with aluminized explosives, interpreted in light of the observed linear variation with detonation pressure of hole depth and volume from jets in uniform targets indicated that aluminum acts effectively as a diluent as far as the end effect, e.g., shaped charge action, is concerned. More careful study showed, however, that aluminum lowers the "detonation" pressure and velocity even more, sometimes quite considerably more, than an ideal diluent. The effectively endothermic reaction of A1 in the detonation wave may be seen, for example, in the results of detonation pressure measuresummarized in Table I, by the shaped charge method (using calibration curves established with known ideal explosives). These data show that

Detonation Reaction Characteristics for CL-20 and CL-20-based Aluminized Mixed Explosives

“…Secondly, if the aluminum particles start to react in the detonation reaction zone, the reaction energy may increase the release time of the explosive detonation energy, which increases the reaction time. However, most previous reports have indicated that the aluminum primarily reacts with the detonation products after the detonation wave front [16,17]. Hence, to understand the effects on the reaction zone and the aluminum reaction, particle velocities during the detonation product expansion should be analyzed.…”

Fireball and shock wave dynamics in the detonation of aluminized novel munitions

“…The effect of the aluminum content in condensed high explosives (HEs) has been studied in some detail [14,[18][19][20][21][22][23]. However, the precise influence of aluminum on shock dynamics is not completely understood.…”

Initiation of Explosives by Exploding Wires. 4. Effect of Wire Material on the Initiation of Petn by Exploding Wires

“…10 The oxida?ion of aluminum in the gaseous phase is assumed to occur according to the following reaction:I! Al(g) + 1/2 0 2(g) -7p AIO (g) High pressures will tend to force the reaction to the right, but high temperature will reverse the reaction.…”