Flank polishing of workpieces with non-uniform stiffness

The additive manufacturing process is expanding rapidly because it enables the production of complex geometries that are difficult to achieve using conventional manufacturing technologies. This process is particularly well-suited for fabricating openwork (lattice) structures and geometries resulting from topological optimization; however, such workpieces often exhibit a non-uniform stiffness distribution. Nonetheless, additive manufacturing typically requires a finishing machining operation. During these operations, cutting forces induce localized, non-uniform deformations in the workpiece, which increase surface form defects. To mitigate this effect, this study develops finishing operations including two advances in this process. The first advance focuses on adapting/distorting the toolpath to improve the obtained workpiece geometry. An experimental validation is conducted using a flank milling operation of a representative openwork workpiece. The experiment demonstrates a 58% reduction in form defects between the nominal and the adapted toolpaths. The second advance determines the optimal combination of radial engagement (applied force) and inclination angle to achieve the most uniform material removal in flank polishing with flexible tools. A semi-empirical model is developed to optimize material removal and ensure homogeneity. To validate this model, an experimental comparison is performed between classical flank polishing and the proposed optimal inclined method (10 N of force and 20° inclination). The results show a 32% improvement in straightness of produced surfaces.