Novel approach to optimize the mechanical properties of Cu-Al composite wires

The present study is concerned with the mechanical properties of Cu-Al wires manufactured via cold drawing. The common approach for improving the tensile strength of drawn wires is to optimize the operational parameters. Those parameters include the die geometry, amount of area reduction at each pass, drawing speed, lubrication and so on. Optimization helps homogenize the plastic deformation during wire drawing. That in turn minimizes the undesirable effect of processing-induced tensile residual stresses forming near the wire surface. The current investigation introduces a novel optimization approach to modify the residual stress distribution with a focus on the fiber-matrix configuration rather than the operational parameters. To that end, residual stress distributions in the two configurations I- conventional copper-clad aluminum and II- so-called “Architectured” wires were compared at the same Cu/Al volume fraction. The comparison was performed using the finite element analysis. Experimental stress–strain curves, numerical residual stress profiles, and equivalent plastic strain contours were then plotted for both conventional and novel configurations. The findings suggest that the novel composite wires offer remarkably better tensile behavior along with other already-known electrical and thermal advantages. This could be ascribed to their architectural features such a continuous copper network and fine Al fibers. Therefore, the new fiber-matrix configuration could remove the need for optimization of various operational parameters or post-drawing treatments for a given wiredrawing set-up.