Correlation of Texture and Residual Stress in Twist Channel Angular Pressed Laminated Al/Cu Composites

Abstract

Composites are generally materials consisting of a minimum of two phases or components, which are selected for their advantageous properties the combination of which provides the final composite material with better specific properties than those of (the original) single-phase materials and alloys. One of the composite types is clad composites, or laminated composites, consisting of layers of individual (metallic) materials. The presented study deals with laminated Al/Cu composite billets, which were processed via the severe plastic deformation (SPD) method of twist channel angular pressing (TCAP). The primary advantage of the SPD methods in general is their ability to introduce significant shear strain, resulting in substantial refinement of the grains of the processed materials, which consequently enhances their properties. The study is specifically focused on assessing the effects of single and double TCAP pass on the specific lattice rotations induced via the severe shear strain within the reinforcing Cu wires, which typically manifest in the changes in residual stress distribution and modifications in texture. The results revealed that after the first TCAP pass, the imposed strain was not homogeneous across the cross-section of the TCAP-ed composite sample as the individual Cu wires featured differences in the distribution of residual stress, as well as in the observed ideal texture orientations. Nevertheless, the second TCAP pass introduced substantial homogenization of the imposed shear strain, which manifested in a more homogeneous distribution of residual stress across the individual wires compared to the first pass. Also, the distribution of ideal texture orientations was more homogenized after the second pass, as all the Cu fibres exhibited the dominance of ideal shear A fibre texture.