Capability study of 2D heat-assisted Mill-Bend process

Integrating bending function into multi-axis machine tools will broaden the capability of current manufacturing equipment. However, capability study must be conducted in order to warranty further exploration of such a hybrid manufacturing strategy. This paper presents the capability study of a heat-assisted Mill-Bend process that implements sheet metal bending on a 3-axis milling machine setup. Specifically, the hypothesis is that sheet metal bending can be effectively performed on milling machines, yielding a commensurable accuracy and repeatability as those from traditional bending machines. To this end, two quality characteristics are evaluated—bending angle and bending radius. In the first part of the work, Taguchi parameter design was used to obtain the optimal process parameters. Under the optimal process parameters, the heat-assisted Mill-Bend process is able to produce an improved consistency on bending angle compared to traditional bending process (15.16% and 17.13% reductions of standard deviation in inner angle and outer angle, respectively) although experiencing a slight increase in spring back. In the second part, an elastic–plastic deformation model was used to predict bending radius. The result shows that the predicted radius agrees well with experimental data. In conclusion, heat-assisted Mill-Bend process produces commensurable bending performance when the process is optimized.