Path planning and pose modulation of arc torch for wire arc additive remanufacturing of deep-cavity narrow-gap hot forging dies

Wire Arc additive remanufacturing (WAAR) provides a high-efficiency route for restoring hot forging dies with stringent precision and complex geometries. However, for deep-cavity narrow-gap dies, intricate spatial structures often induce interference between the arc torch and cavity walls, limiting process stability. This study proposes a collision avoidance algorithm based on arc torch posture adjustment. The remanufacturing region is reconstructed using 3D metrology and Boolean difference operations, while interference zones are detected via a hierarchical bounding box and local separating axis theorem. Based on cavity geometry, the interference regions are classified into the XOZ plane, corners, and YOZ plane. For interference points along contour filling and internal zigzag paths, arc torch posture is adaptively corrected by optimizing normal vector correction and angular adjustment at adjacent interference points. Coordinated optimization of fifth-order polynomial interpolation and melt width regression defines a stable process window (melt width flatness deviation ≤8 %): input power 2700–3000 W, traveling speed 0.40–0.41 m/min, and deflection angle ≤8°. Experiments confirm the method eliminates interference, improves acceleration smoothness by over 10 %, and enhances dimensional accuracy, meeting industrial remanufacturing requirements.