Grain design in ultra-fine Al wire with remarkable combination of strength and conductivity: Ultra-fine-long grains with super strong 〈111〉 texture

Abstract

The trade-off relation between the strength and electrical conductivity (EC) limits the further application of Al wires in the automotive electronic wiring harnesses. In this work, an ultra-fine pure Al wire (UFPAW) with a diameter of around 0.2 mm was successfully prepared by the process of cold drawing → intermediate annealing → cold drawing. It was quantitatively revealed that the ultra-fine grains in the radial section together with the super strong 〈111〉 texture could provide remarkable grain boundary strengthening and texture strengthening, resulting in an ultra-high strength of the UFPAW (228.3 MPa). Besides, the axial long grains could weaken the electron scattering due to the reduction of transverse grain boundaries, leading to a high EC of the UFPAW (63.14 %IACS). Consequently, the ultra-fine-long grains with super strong 〈111〉 texture were proved to be the dominant factors in achieving ultra-high strength and high EC of the UFPAW.