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.