To eliminate internal
defects of grains developed during melt-cast
charging, the formation mechanism and the trend of crystal morphology
of internal defects of 2,4,6-trinitrotoluene and 2,4-dinitroanisole-based
melt-cast explosives under different process conditions were simulated.
The effects of solidification treatment on melt-cast explosive molding
quality were investigated by combining pressurized feeding, head insulation,
and water bath cooling. The single pressurized treatment technology
results showed that grains were exposed to layer-by-layer solidification
from outside to inside, resulting in V-shaped shrink areas of the
contract cavity in the core. The defect area was proportional to the
treatment temperature. However, the combination of treatment technologies,
such as head insulation and water bath cooling, promoted longitudinal
gradient solidification of the explosive and controllable migration
of its internal defects. Moreover, the combined treatment technologies
effectively improved the heat transfer efficiency of the explosive
with the help of a water bath to reduce the solidification time, thus
achieving highly efficient equal-material manufacturing of microdefect
or zero-defect grains.