Influence of die-wall friction and internal energy dissipation on final mean density in multilayer powder compaction - multishock compaction of a copper powder medium in a die by punch impact Ⅶ

摘要

For the compaction of copper powder media of 2-12 layers impacted by a punch with velocities of 20, 35, and 50 m/s, where lower (L) and higher (H) initial densities are arranged alternately, the influences of die-wall friction, internal energy dissipation, separation-reimpingement of the punch and medium on the final mean density are examined. The influence of die-wall friction is the most conspicuous. It has less effect in the L-H-type arrangement where an L layer is impacted by a punch than in the H-L-type arrangement for a given number of layers, because energy loss due to wall friction is smaller in the former. The influence of the energy dissipation and separation-reimpingement is negligibly small.