Effect of charge structure on explosive compaction of W-Cu powder

In explosive compaction technology, strength and action time of shock wave and rarefaction wave in powder directly affect quality of the pressed solid. In order to investigate influence of different factors on pressure change in powder in explosive compaction, based on AUTODYN finite element program, a finite element model of explosive compaction W-Cu powder was established and interaction between explosive, powder tube, and W-Cu powder was realized through a fluid-solid coupling algorithm. The finite element model corresponding to the existing experiment was established. The simulation results were in good agreement with experiment results, which verified reliability of the model and material parameters. Through numerical simulation of explosive compaction process, influence of thickness of charge and thickness of powder tube on explosive compaction pressure was analyzed. The results revealed that the thicker the charge thickness was, the longer the shock pressure action time was, and it was more favorable to powder compaction. With the increase of charge thickness, the increase of action time slowed down. The thicker the powder tube thickness was, the lower the intensity of rarefaction wave in the powder was, and the smaller the influence on pressure entity was. However, with the increase of tube thickness, the central pressure of powder would decrease, and compaction quality of powder would decrease. Therefore, when selecting powder tube thickness, it was important to consider both center pressure of powder and intensity of rarefaction wave on explosion pressure entity.