New method for the manufacturing of curved workpieces by open-die forging

Open-die forging is an incremental bulk metal forming process usually applied for the production of straight workpieces with a symmetric cross-section. A new approach for the integrated open-die forging of curved workpieces is presented, in which the material flow is actively controlled by manipulator displacements. When these displacements are performed during forging strokes, a significant reduction of the bending force compared to conventional bending is achieved. This paper presents the integrated forging and bending process combining several individual forming steps to a forging pass. Based on numerical and experimental investigations, the influence of various process parameters on the workpiece curvature and geometry is discussed.