Dislocations in energetic materials: Part 3 Etching and microhardness studies of pentaerythritol tetranitrate and cyclotrimethylenetrinitramine

An assessment has been made of the primary dislocation slip systems in the explosives pentaerythritol tetranitrate (PETN) and cyclotrimethylene trinitramine (RDX) using a combination of dislocation etching and microhardness indentation techniques. Hardness measurement were made on all major habit faces as a function of temperature and load. These showed that, within the attainable temperature range (PTEN 293 to 353 K, RDX 293 to 373 K) no change in hardness occurred which could be associated with the development of deformation mechanisms additional to those operating at room temperature. The hardness values of both materials were consistent with values obtained in some previous measurements (PETN 17 kg mm super(-2), RDX 39 kg mm super(-2)). Solvent etching with acetone (5 sec at 274 K) proved to be an excellent method for revealing the emergent ends of growth and mechanically induced dislocations in PETN.