Numerical and Experimental Study of Micro Single Point Incremental Forming Process

Single-point incremental sheet forming (SPISF) is a die-less forming process with advantages of high-flexibility, low-cost and short lead time. Recently, micro components have been employed in many applications, especially in medical industry using as implant components, surgical tool and tooth caring accessories etc. Therefore, the reduction of component size to micro -domain has becoming one of the key elements for the development of SPISF technique, which will encounter many challenges, such as reduction of formability, tool wear, inaccuracies in tooling fabrication, etc. This work combined numerical and experimental approaches to study the deformation mechanisms in micro SPISF process. Aluminum 1145 soft-temper foils with thickness of 38.1 gm and 50.8 gm were employed. A truncated pyramid with variable half-apex angle was proposed here as the standard geometry for measuring the maximum forming angle that could be achieved in micro-SPISF process. The influence of process parameters on forming behavior was studied. The result shows that forming angle has direct link with material formability. A full tool path micro-SPISF model has been developed with various 3D element types. It suggests that incompatible mode eight-node brick element C3D8I is capable to capture the shape and thickness distribution of the formed parts with most accuracy and least computational time. The thickness distribution of the workpiece was compared with the Sine Law to unveil the additional stretch region appearing at the top edge of the formed feature in the micro SPISF as compared to macro SPISF. (C) 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the International Conference on the Technology of Plasticity.