Mechanically Induced Damage in Composite Plastic-Bonded Explosives: A Small Angle Neutron and X-ray Study

The principle ingredient of plastic-bonded explosives, the filler explosive, is usually a crystalline material that releases substantial chemical energy when made to react (burn or detonate). A second material, the binder, which is usually an amorphous substance, is added as a minor constituent, one of whose purposes is to coat the filler in order to prevent frictional heat generation during the application of strain. It is important to know the condition of these materials in the composite as formulated and their response to deformation. Small angle neutron and X-ray scattering is used to determine the specific surface area of the interface between (a) filler and binder and (b) the pores. Two radiations are used in order to obtain sufficient contrast variation for the solution (although not unique) of a three-parameter problem. The results strongly suggest that the binder quite effectively performs the intended role. The results also indicate that in heavily mechanically damaged samples the filler particles are fractured and that most of the new fracture surfaces are coated with binder.