抄録
In order to reveal the change in electrical resistivity and strengthening due to plastic deformation and microstructural evolution, investigation of mechanical and electrical properties was performed. From microstructural observations, it was found that the heterogeneous-nano structure having “eye”-shaped twin domains was formed of which volume fraction becomes largest at 90% of rolling reduction. Ultimate tensile strength increases with increasing rolling reduction and reaches about 735 MPa at 90% and 95% reductions. The electrical resistivity measured at 77 K changes from about 39.6 nΩ m to about 61.9 nΩ m, and correspondingly, the conductivity at 293 K changed from about 28.0%IACS down to about 19.9%IACS. When compaering the total changes in electrical resistivity before and after reduction of 80%, the latter was larger. The more obvious changes in mechanical and electrical properties over reduction of 80% are associated with the formation of heterogeneous-nano structure in addition to increasing dislocation density.
This Paper was Originally Published in Japanese in J. Jpn. Inst. Copper 60 (2021) 56–61. Section 2.1 and 2.5 are slightly modified.
Fig. 8 Rolling reduction dependence of (a) electrical resistivity at 293 K and 77 K, and (b) electrical conductivity (% IACS).
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