Study of Fine-Grained Pure Copper Fabrication by Cyclic Contraction/Expansion Extrusion (CCEE) Using Experimental and Finite Element Simulation Methods

摘要

The aim of the present research study is to develop a new SPD technique called cyclic contraction/expansion extrusion (CCEE) based on the well-known cyclic extrusion compression and cyclic expansion extrusion methods, used for the production of ultra-fine-grained pure copper. In this new proposed technique, large amount of imposed plastic strains in one cycle of CCEE decreases number of cycles, remarkably, in order to achieve fine grain microstructures. Obtained microstructures were studied using optical microscopy. The obtained results showed that the grain size of as-received material decreased from 14 to 3m in the proposed technique. Moreover, hardness of pure copper increased from 120HV to about 320HV after plastic deformation, using the proposed technique. Finite element simulation method was implemented to study the plastic deformation during CCEE. Significant effective plastic strain of 3.6 was achieved by one cycle of the CCEE.