Influence of glass microballoons size on the detonation of nitromethane based mixtures

Abstract

Detonation velocities and critical diameters of nitromethane (NM) based explosive mixtures sensitized by glass microballoons (GMBs) were measured. The control parameters of this experimental study were the nature and diameter of the confinement, the GMB size and their mass fraction. As GMB mass fraction is increased, the diameter effect curves (detonation velocity versus reciprocal charge diameter) become less and less dependent upon the confinement nature and size. Furthermore the shape of these curves, which for low concentration of GMBs is concave downward like that of heterogeneous explosive, tends to be straight like that of homogeneous explosives for larger GMB mass fractions. The critical diameter is found to be strongly dependent on GMB size and mass fraction. The mechanism of NM sensitization by GMBs is qualitatively analyzed and estimations of the effect of GMB concentration and size on the critical diameter of the mixtures agree with the experimental results.