Optimizing electric conductivity of innovative Al-Cu laminated composites via thermomechanical treatment

Abstract

For their advantageous combinations of properties, metallic clad composites are popular in numerous commercial and industrial branches. This study deals with measurement and optimization of electric properties of innovative self-designed Al-Cu laminated composites, fabricated by the cold rotary swaging method, via thermomechanical processing. The bimetallic laminates are room-temperature swaged down to the diameter of 10 mm and subsequently subjected to two types of heat treatments, the effects of which are investigated via characterization of deformation behaviours of the component metals, structure observations, measurements of electric characteristics and microhardness. The results showed that the electric characteristics were affected not only by the grain size and preferential texture orientations, but also by the presence of bimodal grains distribution, accumulated dislocations, and twins. The highest electric conductivity (specific resistivity of 20.6 (Omega m) x 10(-9)) and, simultaneously, the highest hardness was observed for the sample featuring bimodal grain size, high density of dislocations, and partial structure restoration. On the other hand, the effect of the applied heat treatment was opposite, with respect to the applied temperature and reduction ratio.