Comparative analysis of quasi-symmetric and staggered inner-milling strategies under different toolpath patterns for deformation control of al 7075-T651 thin-walled plates

Deformation during the machining of thin-walled aluminum alloys is highly sensitive to residual stress redistribution and stiffness variation, representing a critical challenge in aerospace and precision manufacturing. In this study, the deformation behavior of Al 7075-T651 thin-walled plates was comparatively investigated under four machining strategies: contour-parallel (M1), quasi-symmetric sequential (M2), quasi-symmetric staggered (M3), and trochoidal-assisted staggered machining (M4). An integrated experimental–numerical framework combining coordinate measurement machine measurements and finite element method simulations was employed, while the initial material structure was characterized using X-ray diffraction (XRD). Under the investigated conditions, the M3 strategy exhibited the lowest deformation values of 0.109 mm and 0.116 mm during roughing and finishing, respectively. In contrast, the M1 and M4 strategies produced higher finishing-stage deformation values of 0.551 mm and 0.545 mm. The FEM model showed reasonable agreement with the validated M1 condition, yielding deformation values of 0.148 mm (simulation) and 0.126 mm (experimental). M1 provided the shortest roughing time (58 min), whereas M4 required the longest finishing time (70 min). The results suggest that toolpath strategy significantly influences deformation tendency and machining performance. The quasi-symmetric staggered strategy provided the best deformation–time balance, highlighting the potential of machining-sequence-based deformation control in thin-walled structures.