Publications

Abstract not provided.

Vapor-deposited PETN films undergo significant microstructure evolution when exposed to elevated temperatures, even for short periods of time. This accelerated aging impacts initiation behavior and can lead to chemical changes as well. In this study, as-deposited and aged PETN films are characterized using scanning electron microscopy and ultra-high performance liquid chromatography and compared with changes in initiation behavior measured via a high-throughput experimental platform that uses laser-driven flyers to sequentially impact an array of small explosive samples. Accelerated aging leads to rapid coarsening of the grain structure. At longer times, little additional coarsening is evident, but the distribution of porosity continues to evolve. These changes in microstructure correspond to shifts in the initiation threshold and onset of reactions to higher flyer impact velocities.

The explosive BTF (benzotrifuroxan) is an interesting molecule for sub-millimeter studies of initiation and detonation. It has no hydrogen, thus no water in the detonation products and a subsequently high temperature in the reaction zone. The material has impact sensitivity that is comparable or less than that of PETN (pentaerythritol tetranitrate) and slightly greater than RDX, HMX, and CL-20. Physical vapor deposition (PVD) can be used to grow high-density films of pure explosives with precise control over geometry, and we apply this technique to BTF to study detonation and initiation behavior as a function of sample thickness. The geometrical effects on detonation and corner turning behavior are studied with the critical detonation thickness experiment and the micromushroom test, respectively. Initiation behavior is studied with the high-throughput initiation experiment. Vapor-deposited films of BTF show detonation failure, corner turning, and initiation consistent with a heterogeneous explosive. Scaling of failure thickness to failure diameter shows that BTF has a very small failure diameter.

Abstract not provided.

Abstract not provided.