Evolution of the Microstructure and Mechanical Properties of Copper during the Pressing–Drawing Process

Аннотация

New techniques of combined processes of metal pressing are being developed, which are aimed at eliminating billet length constraints, and which include two and more techniques of conventional deformation and severe plastic deformation. The main feature of such combined processes is that they either reduce or completely eliminate the drawbacks of individual processes of metal pressing involved in the combined process. In this work, we analyze how the integrated treatment and conventional techniques of drawing and equal-channel angular pressing (ECAP) as individual processes influence the formation of the ultra-fine-grained structure of copper and its ability to reach a high-strength state as a consequence of each of the involved processes. Copper wire is used as an example to illustrate the features of structure constituent refinements and changes in mechanical properties when the combined pressing–drawing technique with an equal-channel stepped matrix and the conventional drawing technique are used. The results show an increase in refinement of the copper structure both on the surface and in central regions of the wire. This indicates uniformity of the structure over the cross section and, hence, stability of the properties of the obtained wire with an ultra-fine-grained structure.