Investigation of Laser Ablation and Brush Pre‐Treatments for AlCu Cold Roll Bonding in Oxygen‐Free Conditions

Cold roll bonding (CRB), a process that conventionally requires high degrees of deformation, is employed under extreme high vacuum (XHV)‐adequate conditions to promote bond formation. Specifically, surface pretreatments via laser ablation and mechanical brushing are compared for CuAl bonding in oxygen‐free environments with a focus on bond strength evolution, interface morphology, residual stress states and crystallographic texture development. Laser ablation treatment led to superior bond strengths at all tested reduction levels, while both methods converged to similar strength values at high deformation levels. Laser ablation creates interfaces with increased true contact area through enhanced microscopic irregularities. Residual stress measurements show that laser ablation induces beneficial residual tensile stresses, whereas brushing generates residual compressive stresses. In addition, laser‐treated specimens retain preferred cube textures at the surfaces for both bonding partners, reducing crystallographic mismatch. The enhanced performance of laser ablation arises from synergistic mechanisms, as detailed in a multimechanistic framework to foster understanding of CRB under oxygen‐free conditions.