Internal surfaces produced by laser powder bed fusion (PBF-LB) often exhibit poor surface quality due to the layer-by-layer generation mechanism, which critically limits the functional performance of PBF-LB components. Existing post surface processing techniques generally have limited accessibility, low material removal efficiency, or insufficient tool durability, particularly for titanium alloys. Here, a novel electroplated magnetic grinding tool is developed for magnetically driven internal finishing (MDIF) of PBF-LB Ti-6Al-4V tubes. The tool integrates a drum-shaped NdFeB magnetic core with a bonded electroplated superabrasive layer, enabling stable self-rotation under an externally rotatory magnetic field and consistent abrasive–surface interaction without traditional mechanical transmissions inside the tube. Results show that stable material removal can be maintained for 360 min of continuous polishing. Surface roughness decreased from >7 μm Ra to 1.2–1.4 μm Ra, corresponding to an improvement of ∼80% and an average material removal rate of 4–5 mg/min (corresponding to 38–40 μm/min in depth) was achieved. Uniform finishing of complex tubes was further demonstrated through section polishing experiments with designed tool paths. The proposed electroplated tool and MDIF strategy provide a robust, efficient, and geometry-adaptive solution for improving internal surface quality in additively manufactured components with difficult-to-access cavities.HighlightsElectroplated magnetic grinding tool for PBF-LB Ti-6Al-4V tubes' internal finishingStable polishing for 360 min without severe tool wearAchieved a material removal rate of approximately 4–5 mg/min (38–40 μm/min)Reduced surface roughness by 80–85% to approximately 1.2–1.6 μm RaSuitable for straight, curved and diameter-varying PBF-LB Ti-6Al-4V tubes
SHAO et al. (Mon,) studied this question.