The Influence of Lattice Imperfections on the Chemical Reactivity of Solids. The Growth, Perfection and Defect Properties of PETN (Pentaerythritol Tetranitrate) and RDX (Cyclotrimethylene Trinitramine) Single Crystals. Part 2.

An assessment has been made of the primary dislocation slip systems in the explosive pentaerythritol tetranitrate (PETN) and cyclotrimethylene trinitramine (RDX) using a combination of dislocation etching and microhardness indentation techniques. Hardness measurements were made on all major habit faces as a function of temperature and load. These showed that, within the attainable temperature range (PETN 292-353, RDX 293-373K) 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 17kg/sq.mm, RDX 39kg/sq.mm). Solvent etching with acetone (5s at 274K) proved to be an excellent method for revealing the emergent ends of growth and mechanically induced dislocations in PETN. Etching of microhardness indentations confirmed that observable slip traces comprised dislocations. These migrated up to 160 micrometers (20g load) from a (110) primary slip plane.
See also Part 1, AD-A141 271.