Detonability of suspensions explosives in nitromethane

The detonability of mixtures of solid and liquid explosives (explosive suspensions) has been little studied, although they are part of plastisol and paste explosive compositions widely used in practice. In this work, the critical detonation diameters of suspensions of PETN, RDX, HMX, and FOX-7 os various dispersion (specific surface area 350–7000 cm$^2$/g) in nitromethane. The content of crystalline explosives in suspensions was 3–60 wt.%. Suspensions were prepared using a vibrovacuum method. The sedimentation stability and homogeneity of suspensions was ensured by their thickening with a small addition of aerosil (2.0–2.5%). Charges of suspensions were prepared in thin-walled polyethyleneterephthalate tubes of various diameter. Thus, the critical detonation diameter of explosive suspensions was determined in fact for charges without a shell. The dependences of the critical detonation diameter of suspensions on the volume fraction of solid explosives have the same S-shaped form. The effect of the dispersion of explosives on these dependences was shown. Obtained dependences for suspensions of solid explosives in nitromethane were compared with similar experimental dependences for other explosive systems: solutions of liquid explosives in nitromethane; solutions of solid explosives in nitromethane; binary mixtures of finely dispersed solid explosives; binary mixtures of coarsely and finely dispersed explosives; compositions containing mixtures of coarsely and finely dispersed explosives and inert binder. It is shown that the dependences for binary mixtures of coarsely and micron-size explosives and compositions based on these mixtures (distinct heterogeneous systems) the same form as for suspensions.