Multi-stage Single-Point Incremental Forming: An Experimental Investigation of Surface Roughness and Forming Time

This paper describes an experimental investigation of surface roughness and forming time of parts formed by multi-stage single-point incremental forming (MSPIF). Process parameters, namely tool size, feed rate, step depth, sheet thickness, and spindle speed, are considered in the present study. Experiments are designed using the central composite design (CCD) method. Analysis of variance (ANOVA) is used to identify significance of process parameters for surface roughness and forming time. It is found that tool size is the most significant process parameter followed by step depth, spindle speed and sheet thickness for influencing surface roughness. Surface roughness initially decreases and then increases with increase in tool size. It decreases with decrease in step depth, spindle speed and sheet thickness. For forming time, step depth and feed rate are found significant. Forming time decreases with increase in step depth and feed rate. Regression models of surface roughness and forming time are also developed. Further, process parameters are optimized to minimize surface roughness and forming time of parts.