Weak detonation in mixtures of phlegmatized RDX with aluminum

Abstract

The Zel’dovich theory predicts the possibility of realization of self-sustained weak detonation in systems with nonmonotonic energy release. The present paper describes experiments aimed at detecting such a regime of detonation in mixtures of phlegmatized RDX with PP-1 and PAP-2 aluminum powders. The mass fraction of aluminum was 20%. To examine the detonation regimes, 70-mm-in-diameter charges of these mixtures were initiated with powerful triangular pressure pulses, which gave rise to attenuating overdriven detonation waves. The pressure profiles were recorded at various distances from the initiation plane (from 10 to 80 mm). Specific features of the time evolution of the detonation wave profile indicative of the existence of a supersonic flow region arising not later than 0.15 μs behind the shock front were revealed. The supersonic character of the flow behind an intermediate C-J plane is an inherent characteristic of self-sustained weak detonation; i.e., direct experimental evidence for the existence of weak detonation in RDX-aluminum mixtures was obtained.