Microstructural and Mechanical Evaluation of Pure Copper Rods Processed by Severe Plastic Deformation Method of Hydrostatic Cyclic Extrusion Compression

In this study, a severe plastic deformation method of hydrostatic cyclic extrusion compression (HCEC) was used to produce ultrafine-grained copper rods. The process was applied up to two cycles on annealed copper rods and microstructural and mechanical properties of the produced specimens were investigated. The optical and transmission electron microscopy results revealed a notable decrease in the grain size of the sample after the HCEC process. The average grain size of the copper sample after the second cycle of the process reached ~ 292 nm compared to the initial size of ~ 32 μm. Mechanical investigations revealed a considerable increase in the strength and hardness of the samples. The ultimate tensile strength of the copper rods increased to 441.7 MPa after the second pass of the process. Also, the microhardness value increased ∼ 73.4% compared to the initial sample. Generally, HCEC is a notable technique to produce ultrafine-grained copper rods with high lengths and superior characteristics, which can fulfill the requirements of different industries.