Research of energy deposition caused by pore collapse

Mechanisms of energy deposition at the interface of particles in explosive compaction of metal powders are analyzed. A one-dimensional model of a spherically symmetric pore is proposed to reflect the collapse. The effect of heat conduction is taken into account in axisymmetric flow equations, and the temperature distribution during the sphere collapse is solved by the finite-difference method under the assumption that the material is rigid-plastic or thermoviscoplastic. The results show that the effect of heat conduction becomes more remarkable if the scale of the holes is small. During the collapse, the inner surface is converted from the elastoplastic to the fluid state, and its temperature becomes much higher than that of the remaining part of the sphere, which favors retaining of the amorphous structure in explosive consolidation of amorphous powders.