Controllable Crystallographic Texture in Copper Foils Exhibiting Enhanced Mechanical and Electrical Properties by Pulse Reverse Electrodeposition

Abstract

The texture evolution in copper foils prepared by a rapid pulse reverse electrodeposition (PRED) technique using an "additive-free" electrolyte and the subsequent correlation with the mechanical and electrical properties is investigated in this study. Control over (111), (100), and (101) crystallographic textures in copper foils has been achieved by optimization of the pulse parameters and current density. A hardness as high as 2.0-2.7 GPa, while the electrical conductivity was maintained in the same range as that of bulk copper, was exhibited by these foils. A complete study of controlling the (111), (100), and (101) textures, CSL Σ3 coherent twin boundaries, grain refinement, and their effect on the mechanical and electrical properties is performed in detail by characterizing the foils with electron backscatter diffraction, X-ray diffraction, nanoindentation, and electrical resistivity measurements. The PRED technique with short and high-energy pulses allowed the (111) texture with increase in forward off-time, while the optimized current density resulted in the formation of (100) and (101) textures. The reverse/anodic pulse applied after every forward pulse aided the minimization of residual stresses with no additives in the electrolyte, the stability of texture in the foils, grain refinement, and formation of growth twins. Among the three highly textured copper foils, those with dominant (111) texture exhibited a lower electrical resistivity of ∼1.65 × 10-6 Ω cm and better mechanical strength compared to those with (100) and (101) textures. (Graph Presented).