Rate of detonation

The incorporation of aluminum increases the blast effect of explosives but decreases the rates of detonation, fragmentation effectiveness, and shaped charge performance. Mixes with aluminum are made by first screening finely divided aluminum, adding it to a melted RDX—TNT slurry, and stirring until the mix is uniform. A desensitizer and calcium chloride may be incorporated, and the mixture cooled to ca 85°C then poured. Typical TNT-based aluminized explosives are the tritonals (TNT + Al), ammonals (TNT, AN, Al), minols (TNT, AN, Al) torpexes and HBXs (TNT, RDX, Al) (Table 14) (223-226). 

The Relation Between the Rate of Detonation and Lead Block Expansion of... 

Its impact sensitivity was comparable to RDX, and the Trauzl Pb block expansion was found to be 130 (PA 100). The rates of deton of 30mm diameter charges in cardboard tubes were 5630m/sec at d 1.10g/cc,6970m/sec at 1.50g/cc, 7560m/sec at 1.60g/cc, and 7830m/sec at 1.65 g/cc. Medard concluded that Methylglucoside... 

The Rate of Detonation of Various Explosive Compounds , OSRD 1219 (Feb 1943)... 

Myrite. An expl contg a mixt of nitrogen dioxide and carbon bisulfide. Its sensitivity to mechanical influences, brisance, rate of deton, and other expl characteristics were detd at PicArsn in 1940. In view of the fact that it is specially sensitive to rifle bullet impact, and has a rate of deton and brisance considerably lower than TNT, it was concluded that Myrite is not suitable for use as a military expl Ref C.J. Bain, Investigation of the Explosive Myrite , PATR 1030(1940)... 

A new compn was developed consisting of RDX 35.9, NC (1-2.6% N) 24.5, NG 22.8, DNEtB 10.0, DBuPh 6.6 DPhA 0.2%. It was tough and thermally stable, relatively non-hygroscopic, and insensitive to friction, impact and rifle fire. It was also superior to TNT in rate of detonation and brisaiice. A relatively simple and non-hazardous procedure was developed for its manuf. Another formulation variation was TNT 35, Comp A-3 35, M-l proplnt powder 20, and DNEtB or TEGDN 10%. This was hard and tough at room temp, but softened at 65° (Refs 1 3)... 

Its rate of deton is comparable to that of LA and its thermal stability is quite good (no weight loss at 80° for several days). It bums in air, producing a hot flame... 

Fig 2 The relation between the rate of detonation (density 1.04) and lead block expansion of mixtures of PETN and TNT, and their composition (according to T. Urbanski) (Ref 1)... 

Its rate of detonation, as detd by the Dautriche method, was about the same as that of TNT (6880m/sec). Its sensitivity to impact, as detd in Fr, was considerably lower than for PA, but according to tests conducted in Engl, TNPht was more sensitive than PA (Ref 8). When pellets of TNPht (d 0.25g/cc) were fired in a manometric bomb, the pressure developed was 2490kg/sq cm, as against 3230 for PA... 

Explosive D is approx 80% as brisant as TNT, as indicated by sand tests, but fragmentation tests in shell have shown it to be about 95% as brisant. Both expls have about the same rate of detonation at a d of 1.56g/cc hence, approx equality of brisance would be expected. The rate of detonation of Explosive D has been found to be somewhat affected, particularly at lower loading densities, by the granulation of the material, but this effect is not pronounced. Its expl strength is 98% that of TNT, as evidenced by the ballistic pendulum test (see below)... 

The distortion which brings about the breaking carries a portion of the material forward and because of the intense pressure generated behind the wave, the reciprocal movement of the medium is prevented. The forward movement of the medium and the prevention of counter-movement serve to increase the speed of the wave front. This effect explains the fact that the rate of detonation increases more rapidly with increase of density in an insensitive than in a sensitive explosive. The insensitive material must be distorted and moved forward to a greater extent than the sensitive material before rupture occurs... 

When the rates of deton are plotted against densities, approx straight lines can be obtained when the interfering factor (such as impurity, confinement, differences in granulation, etc) are considere d. A straight line... 

Carl gives the following formula for the straight line representing the rates of detonation ... 

The sensitivity of expls is a characteristic of great importance and can be correlated with the rate of deton. Perfect crysts and other nearly perfect elastic materials are the most sensitive, while liquids or colloids (plastic, fluid or hard) resist initiation and also have tendency to damp out-the wave of deton. The sensitivities of endothermic and exothermic compds are different and this causes them... 

The power and brisance of expls do not depend upon the rate of deton but rather on the energy of formation of expl and the energy of recombination of products of deton. The different valence bonds of the same compd may be of different sign in respect to their heat of formation... 

Rate of Detonation Determination. See Detonation Rate (or Velocity) Determinations... 

But when the shock effect is impinged on other matter, it is indicated by its shattering effect (brisance) - not by the total work effect of the explosive. This might be proved by making Sand Tests of Tetryl loaded at different densities. With different densities and consequent different rates of detonation, there should be different amounts of sand crushed ... 

Dunkle stated (Ref 7, p 281) that a higher rate of detonation is a general result when the deton front is concave forward. Poulter (Ref 5) reported that studies at SRI of the velocity of convergent detonation fronts have indicated a relationship in the following form ... 

Their conclusion was that 16 hr storage at —65° 70°F of the above HE s did not affect their, deton rates, but 72-hr storage of TNT at 140°F caused appreciable lowering of its rate of detonation... 

Calculation of deton vel by the formula of Berthelot) 92-6 (Exptl detn of deton vel by chronographs of LeBoulenge and Mettegang) 97-8 (Detn by accelograph of Duprez) 98-100 (Detn by. Dautriche method) 33) D.P. MacDougall et al, "The Rate of Detonation of Various Explosive Compounds and Mixtures , OSRD 5611(1946) 34) C.R. Niesewanger 8c... 

TM9-1910 (1955), 41-2 (Rate of deton) 55) E.F. Pound M.A. Cook, "The Measurement of Detonation Velocity by Microwave Resonator Techniques , Univ of Utah, TechRept 44(1955), Contract N7-onr-45107 56) H.T, Knight ... 

A theory of the dependence of the rate of deton of solid expls on the diam of the chge)... 

Accdg to Ryabinin (Ref 2, it has been reported that high pressures favor (for some expls) the rate of deton. 

Note PA primers were used in each test. A specially constructed device was used for measuring vels of molten samples, such as at temps of 173 183°all the above expls, except PA. Extremely high vel for TNN at 183° was due to decompn of chge prior to initiation McGarry Stevens (Ref 2) detd by drum camera method the rates of deton of Tetryl, RDX Comp A-3 (all in pelleted form) 50/50 Pentolite, TNT Comp B (all cast) and hand-tamped Comp C-4. The rates of these sticks 1-1/8 inch in diam by 18 inches long were measured after exposure to initial low, ambient and high temps. It was found that the deton rates of these expls,... 

Inulin nitrate (13.75%N) 20, NaN03 11, Pulp (such as wood pulp) 4. This dynamite has a rate of detonation of 2310 m/sec, weight per 114 stick - 120g cartridge cont 378 per 100 lb sensitiveness (gap test) 4 weight strength 53.5%. It flows and packs easily, is not dusty, does not freeze and does not cause headaches... 

Oshiyaku. A yel, press-loaded expl compn consisting of PA 90 wax 10%. It was much less sensitive to Impact Friction than straight PA and had lower Brisance, Power and Rate of Detonation. It was used as Bursting Charge in nose of some Armor-Piercing Projs, such as Type 95 7-cm (70-mm) AP Proj listed in Ref 3, p 309 (See also Ref 1, p 26 Ref 5, p 368)... 

Raiko (Army) or Raisansuigin (Navy) Thunder Mercury . Mercuric Fulminate, Hg(ONC)2 mw 284.65, N 9.84% white to gray pdr, d 4.43, mp—decomp or detonates without melting Brisance by Sand Test—ca 55% TNT Expin Temp 210° in 5 secs Impact Sensitivity, BurMinesApp, 2-kg wt—5cm Power by Trauzl Test—51% TNT Rate of Deton 5000 at d 4.0 (AMCP 706-177, listed as Ref 8, p 201). Used straight by the Japanese in Instantaneous Fuzes, in Blasting Caps and in mixture called Bakufun (Ref 1, p 25 Ref 5, p 369)... 

Mortar 92% PA Rate of Deton 7100m/s vs 6900 for TNT. It was used at the beginning of Shaped Charge. See Hollow Charge [Ta(dan)]... 

---