Using high-pressure torsion for the cold-consolidation of copper chips produced by machining

High-pressure torsion (HPT) was used to consolidate chips machined from coarse-grained copper and from copper processed by ECAP. The results are compared with discs prepared by HPT and with discs processed by a combination of equal-channel angular pressing (ECAP) and HPT. It is demonstrated that the consolidated discs have exceptionally fine microstructures and high hardness. The results suggest the possibility of a saturation in grain refinement which may be related to a release in heat during high-pressure straining.