Modeling and simulation of the hybrid WAAM-rolling process for aluminum high-rib components with consideration of multi-pass morphology inheritance

Inter-layer rolling integrated with wire arc additive manufacturing (WAAM) effectively improves inherent defects (poor interlayer bonding, high defect density, and inferior mechanical properties) in aluminum alloys by introducing severe plastic deformation. However, the alternating WAAM-rolling process faces bidirectional interdependencies: WAAM-deposited rib morphology influences rolling strain distribution, while rolled surface geometry alters subsequent WAAM energy distribution and material deposition. Morphology inheritance across passes critically determines the forming accuracy of high-rib structures. Unfortunately, existing models oversimplify this by assuming idealized geometries, leading to unreliable predictions. To this end, a high-precision numerical model for WAAM-rolling was developed here, incorporating true rib morphology from prior passes as initial conditions to achieve bidirectional morphology inheritance. An integrated multi-pass simulation framework was established to analyze rib evolution under various roller types and rolling reductions. Results demonstrate that lateral restraint rollers significantly improve rib accuracy (± 0.01 mm) and molten pool spreading. Both 50% reduction per layer and 40% reduction per double-layer yield uniform strain, but the latter achieves higher efficiency. Optimized parameters (10 mm/s feed rate, 340 °C rolling temperature) were derived to develop a hybrid WAAM-rolling strategy. The proposed approach successfully produced high-rib aluminum components with sub-0.01 mm accuracy, underscoring the importance of morphology-controlled process integration for high-integrity WAAM structures. This work provides a novel modeling framework and practical guidelines for precision hybrid additive manufacturing.