Effects of twist channel angular pressing on structure and properties of bimetallic Al/Cu clad composites

Abstract

This study documents the effects of the twist channel angular pressing (TCAP) on the structure and selected properties of Al/Cu clad composites. Processing of the designed clad composite via single, as well as double pass TCAP was performed experimentally, and simulated via the finite element method. The deformation behaviour predicted via the simulation was verified experimentally by 3D Micro-CT scanning, and by structure analyses. The results revealed that the single pass introduced significant deformation strengthening of the Al/Cu composite components, and after the second pass, the effective imposed strain in the Al sheath approached the value of 5. The composite sheath also exhibited more or less homogeneous distribution of residual stress of the lowest observed absolute values, and the smallest observed average grain size - slightly above 1.5 μm. The Cu grains in the structures of the wires within the extruded composites also refined significantly, especially after the second pass, to almost 3 μm. However, the analysed parameters exhibited slight variations across the cross-sections of the composite billets. This can be attributed to phenomena related to the (differences in the) plastic flow. The intensive imposed shear strain also imparted increase in microhardness and changes in thermal conductivity.