Roll bond welding produces a strong, intermetallic compound-free butt weld between aluminum and copper

Abstract In this study, a solid-state welding method based on rolling was successfully developed. For this purpose, Aluminum (Al) 1050 sheets and commercial pure copper (Cu) sheets, each with a thickness of 2 mm, were used. The sheets were cut at a 30° angle at the contact interface and bonded together via cold rolling with a 60% thickness reduction. After rolling, due to the imposed strain, the 30° angle decreased to 12°. Optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), energy-dispersive spectroscopy (EDS), microhardness, and tensile strength tests were employed to investigate the microstructure and mechanical properties of the weld. In addition, the commercial finite element package Abaqus was used for numerical simulation. The rolling reduced the average grain size of Al and Cu from 35 μm to 5 μm to 5 μm and 2 μm, respectively. EDS analysis showed that no intermetallic compounds (IMC) formed at the Al/Cu interface, confirming that bonding occurred primarily through mechanical interlocking rather than atomic diffusion. Kernel average misorientation (KAM) maps derived from EBSD analysis revealed a higher strain concentration at the Al/Cu interface compared to other regions of the sample. The numerical simulation confirmed the EBSD results. The tensile strength of the welded sample was 148 MPa, which was equal to that of the rolled Al in this study. During tensile testing, fracture occurred in the Al region, while the weld remained intact.