The methods of severe plastic deformation (SPD) of metals and metal alloys are very attractive due to the possibility of refinement of the grains to nanometric sizes, which facilitates obtaining high mechanical properties. This study investigated the influence of SPD in the process of hydrostatic extrusion (HE) on the anisotropy of the mechanical properties of the CuCrZr copper alloy. The method of HE leads to the formation of a characteristic microstructure in deformed materials, which can determine their potential applications. On the longitudinal sections of the extruded bars, a strong morphological texture is observed, manifested by elongated grains in the direction of extrusion. In the transverse direction, these grains are visible as equiaxed. The anisotropy of properties was mainly determined based on the analysis of the static mini-sample static tensile test and the dynamic impact test. The obtained results were correlated with microstructural observations. In the study, three different degrees of deformation were applied at the level necessary to refine the grain size to the ultrafine-grained level. Regardless of the applied degree of deformation, the effect of the formation of a strong morphological texture was demonstrated, as a result of which there is a clear difference between the mechanical properties depending on the test direction, both by the static and dynamic method. The obtained results allow for the identification of the characteristic structure formed during the HE process and the more effective use of the CuCrZr copper alloy in applications.

Mating electrodes made of copper alloys are commonly used for welding galvanized steel sheets used in the production of car bodies. These alloys are characterized by high mechanical properties, a high level of electrical and thermal conductivity as well as the stability of these properties under changing conditions of current, thermal and mechanical load. Much careful attention was paid to the essence of the ongoing structural changes as well as to the mechanical properties in the welding process (RSW – Resistant Spot Welding) of steel sheets, including high-strength ones. There is a lack of research on structural changes and the related mechanical properties occurring in welding electrodes made of copper alloys caused by the welding process.
This study is devoted to these issues and contains a critical review of the research results enabling a better understanding of the relationships between the structure and properties of welding electrodes caused by the cyclic welding process. In order to illustrate the phenomena occurring during the welding process, both in the material to be welded and in the tip electrodes, hardness and structural tests were carried out on electrode samples before and after their exploitation. The data collected in the article supplements a certain lack of information in the literature regarding the microstructural aspects of the welding process of galvanized steel sheets for the production of car bodies. The conducted research may be the starting point for the search for more effective materials for the tip electrodes.