Changes in electrical and mechanical properties of additively manufactured CuCrZr alloy due to thermal exposure and plastic deformation

Additive manufacturing (AM) of Cu alloys offers high potential to improve the efficiency and performance of electrical components, e.g. in electric motors. Considering potential applications, mechanical and thermal loadings occur and hence, their impact on the material properties must be understood. Consequently, in this work the influence of thermal (200 °C, 24 h) and mechanical loading (total strain of 2 %) on the mechanical properties, i.e., hardness and cyclic hardening potential, and the specific electric resistance of specimens made of CuCrZr alloy and manufactured via laser-based powder bed fusion (PBF-LB/M), was studied. The specimens were analyzed in different conditions, i.e., as-built, direct-aged after PBF-LB/M, and solution-annealed after PBF-LB/M followed by aging. The results show that thermal exposure, mechanical loading, and a combination thereof have a significant effect on the mechanical and electrical properties. Microstructural assessment of thermally loaded specimens indicates that the changes in the properties are caused by a change in the grain structure (including texture), the dislocation density and structure as well as the precipitation state. Note that the effects of the loadings applied on the material properties differ between the investigated conditions and hence, not only the initial properties, but also their stability can be adjusted.