Behavior of explosive compacted/consolidated of nanometric copper powders

Nanosized particles of copper have been explosive compacted/consolidated with different process conditions using a cylindrical configuration as lay out, in order to preserve nanocrystallinity in 3D parts. After processing the specimens were characterized regarding the density, microstructure, grain size, and hardness using Archimedes method, SEM, XRD and depth-sensing indentation, respectively. The results show a significant bulk densification after explosion, associated to a nanocrystalline character, similar to the starting powders. For the sharpest parameters selected for the explosion a bimodal distribution of grain size is visible by SEM comparable to 2D nanocrystalline copper deposited by sputtering. The properties of “sintered parts” are compared with those of a standard resulting from densification of micropowders using the same technology, and the results highlight the future role of explosive densification of ductile nanopowder metals, as a suitable technique for macro- and micromanufacturing of nanostructured parts.