Feature-based double-sided deformation machining approach for manufacturing freeform monolithic components

In the deformation machining (DM) approach, the machining and incremental forming operations are combined to utilize the strengths of the two processes to produce monolithic components with thin structures using a single setup. DM offers a high degree of flexibility to manufacture monolithic components in comparison to conventional techniques. Some freeform monolithic products are difficult to machine with the 3-axis machining approach due to restricted entry of the tool in certain portions of the geometry. This paper presents a novel double-sided deformation machining (DSDM) technique to manufacture freeform double-sided monolithic components. As a test case, a double-sided monolithic impeller-shaped structure with freeform blades is manufactured with the proposed technique. For this, first, a blank is machined to create the required structure and blades of desired thickness. These machined structures are used as preforms for the incremental forming (bending) of the blades to the final shape. As the existing commercial toolpath development packages are not compatible with the DM process, a novel feature-based double-sided combined machining-forming toolpath is developed for the DSDM operation. Here, the blades are deformed separately and sequentially. This avoids the collision issue and achieves a faster forming operation. To evaluate the quality of the monolithic components developed, a few response parameters, like the process forces, the geometrical accuracy in terms of springback, and the surface roughness, are reported.