Copper-aluminum composites are widely employed in industry due to their excellent mix of engineering performance and cost savings. Solid-state diffusion bonding is hampered by the oxide layers at the interface, though, because these layers prevent the creation of intermetallic compounds. Significant activation energy is needed to overcome this barrier, which raises energy use, time, expenses, and CO2 emissions. Understanding the atomic-scale deformation mechanisms behind the production of intermetallic compounds is essential to addressing issue. Using classical and advanced neural network interatomic potentials, this study uses molecular dynamics simulations to examine the kinetics of solid-state diffusion bonding of Al-Cu. Aluminium single crystals experience plastic deformation during bonding, which leads to the production of dislocation networks. The formation of intermetallic compounds like Al2Cu in oxide-free circumstances is facilitated by the formation of Guinier–Preston zones at the Cu/Al interface, which we found to occur in nanoseconds. These revelations improve our knowledge of atomic-scale mechanisms that are essential for improving bonding methods and lessening their negative effects on the environment.