Hybridization of metal spinning and incremental sheet forming to produce curvilinear surfaces of revolution using deep drawing quality steel

Abstract

Metal Forming Process (MFP) is the imperative backbone of current manufacturing industry. MFP is the process of converting the raw material in to finished product by plastically deforming the metal into the required shape or geometry by the application of force. MFP is partitioned as two major groups namely bulk forming process and sheet MFP. Sheet metal operations like bending, drawing, shearing, blanking, punching are mostly carried out in presses using a set of tools called as die and punch. Metal Spinning Process (MSP) and Incremental Sheet Forming Process (ISFP) provide an alternative method for manufacturing low-volume functional flexible sheet metal products. In these two processes, the parts were formed by creating localized plastic deformation on the blank by either forming tool or forming roller, which moves with the aid of Computer Numerical Control (CNC). In MSP, the required shape is formed by combining the rotational motion of blank and forcing the tool against the blank. In ISFP, the parts are formed by combining the linear motion of the blank and forcing the rotating tool against the metal blank. The major process defects of ISFP were geometrical accuracy of finished parts, difficulty in manufacturing parts having the wall angle nearer to 90° or above 90°, cracks, high process time and poor Surface Finish (SF). Due to the local metal blank deformation, wall thickness variation and defects related to thinning were seen in ISFP and MSP. On the other hand, the MSP had issues related to cracks, wrinkling failure and SR. With these issues, the application of ISFP and MSP were confined to manufacturing parts that possess asymmetric profile. But with the advantages possessed by MSP and ISFP such as lesser forming load and inexpensive tooling with small-batch production, these two forming processes have undergone a renaissance in recent years newline