Density–Energy Relationships in Explosive Compaction of Metal Powders

Abstract

Powders of copper, iron, APK1 superalloy, and RSR aluminium alloy have been compacted in steel tubes of varying wall thickness using Trimonite explosive. It was assumed that compaction occurred by a rapid acceleration of the tube wall, which in turn collapsed on to the metal powder to effect compaction. The maximum tube velocity was estimated on the basis of a relationship applicable to the acceleration of flat plates under the influence of detonating explosives. Empty tubes were collapsed explosively to determine the energy absorbed during collapse to a specified strain. In compaction tests, the energy required to compact the powder was determined by subtracting the tube deformation energy from the total initial kinetic energy of the tube. The results show that definite relationships exist between the specific kinetic energy applied to the powder and the compacted density achieved. These relationships are similar to relationships established between applied pressure and compacted density in isostatic and die compaction. PM/0449