Effects of Process Parameters on Forming Forces and Surface Quality in Micro-Single-Point Incremental Forming

Abstract Micro-Single-Point Incremental Forming, the process of shaping parts with at least two dimensions smaller than 1 mm, is a promising microfabrication technique known for its near-net-shape capability and high productivity. The growing trend of miniaturization across various industries has led to increased demand for microproducts and microdevices. The influence of forming parameters is critical for improving metal formability as well as enhancing geometrical accuracy and productivity. Accordingly, this article aims to examine the influence of forming parameters, such as spindle speed and feed rate, on mean forming forces, force deviations, and their subsequent effects on the surface quality of 304 stainless steel parts fabricated using single-point incremental forming. Experiments were conducted using 304 stainless steel foils of thickness, formed with slender forming tools featuring ball-nose tips of 3 mm and 1 mm diameters, both with a tool height of 12.5 mm. Frustum pyramids were formed with edge radii of 500μm and step-down of 100μm, with varying spindle rotation and feed speeds. The surface quality was analyzed quantitatively using a handheld stylus profilometer and force data of the formed surfaces. This systematic approach helped identify the optimal forming parameters for slender tool applications in μSPIF. The optimal parameters determined were a tool speed of 6000 rpm and a feed rate of 750 mm/min. The results were experimentally verified through the successful forming of a two-shaped geometry comprising a hybrid pyramid and cone geometry using the identified tool speed and feed rate.