Microstructure of Plastic Bonded Explosives and Its Evolution after Thermal and Mechanical Aggressions

Because sensitivity of an explosive is highly controlled by its microstructure, it is very important to examine and characterize it. Both scanning electronic microscopy and polarized light microscopy were chosen to .examine the microstructure of selected plastic bonded explosives. The initial microstructure of hot pressed plastic bonded explosives and its evolution under thermal and mechanical aggressions were studied. To better reveal the microstructure, polishing and etching techniques were developed to prepare the samples of microscopic examination. The thermal aggressions included low temperature freezing and frozen combustion. Mechanical aggressions included quasi-static Brazilian test, uniaxial compression, ultrasonic wave insult and long-pulse low-velocity impact. The characteristic damage modes under different solicitations were analyzed.