Feasibility of Aluminum-Copper Bimetallic Bar Production by Combined Equal Channel Angular Pressing and Direct Extrusion Process

In this study, the feasibility of aluminum-copper bimetallic bar production was investigated. The aim was to achieve a strong interlayer bond so that the mechanical properties of the produced bar be better than embedded metals. For this purpose, an equal channel angular pressing process (up to a maximum of four passes) together with two steps of direct extrusion process (before and after ECAP process) was considered. The effect of stored strain in each step on the strength of the bond and some other mechanical properties was investigated. In bimetallic samples that were subjected to two steps of direct extrusion, the compressive yield strength and bond shear strength were 263 and 9.4 MPa, respectively. Applying and repeating the ECAP process increased these values so that for the bimetallic samples under two steps of direct extrusion plus 4 passes of ECAP, compressive yield strength and bond shear strength increased by about 38% and 150%, respectively. Comparing the hardness of the primary and final samples showed a significant increase in the processed samples. The results were confirmed using the microstructure analysis of copper and aluminum and observation of the bonding layer in each of the bimetallic samples.