Single-crystal mechanical behavior and melt-cast detonation velocity of cyclic nitrosamine R-salt

Cyclotrimethylenetrinitrosamine (R-salt) is a fairly insensitive explosive that can be easily prepared from hexamine, sodium nitrite, and hydrochloric acid. This nitrosamine is of interest because of its similarity in structure to the reduced form of the nitramine, RDX, and its melt-castable nature. Mechanical characterization of organic crystalline materials like R-salt is difficult and not often done on pure materials due to the test geometries required of many common mechanical characterization methods. Here, nanoindentation techniques were used to determine single-crystal mechanical properties of R-salt, including hardness, elastic modulus, yield strength, and fracture toughness. Additionally, the detonation velocity was determined using rate stick measurements for the pressed and cast-cured material. Both the detonation behavior and the mechanical properties are compared to the fully oxidized analog RDX, as well as several other traditional explosives.