INITIATION AND PROPAGATION IN PRIMARY EXPLOSIVES

The initiation and propagation of deflagration and detonation in mercu ry fulminate, lead azide, mercuric-5-nitrotetrazole and silver-5-nitro tetrazole have been studied using various techniques. Streak and frami ng high-speed photography were used to observe these events directly. The main aim has been to investigate the factors which affect deflagra tion-to-detonation transition (DDT) and the related phenomenon of dead -pressing, which may be regarded as a failure of the DDT process at hi gh pressed densities. These factors include the variable properties of pressed density, void structure, confinement and charge dimension and geometry, and also fixed properties (for a given explosive) such as s hock and thermal sensitivities, heat of explosion and the quantity and state of the reaction products. The nature and strength of the initia ting stimulus also have a major effect on the subsequent reaction.