This study aims to explore stretch flange micro-forming and springback of metal foil. In this study, first the explicit dynamic finite element method is applied to simulate the stretch flange micro-forming of metal foil. And then the implicit static finite element method is applied to analyze the stretch flange springback. In order to verify the accuracy of the numerical simulation, a set of dies is designed for the experiments of stretch flange micro-forming to explore the accuracy of the various results using the finite element method.
In this study, the rolled copper foil and SUS304 stainless steel are used for analyses and experiments. The maximum punch load, the springback angles, and the workpiece profile of the numerical simulation are compared with those of the experiment. The maximum punch load for rolled copper foil from the numerical simulation was 0.7153N and 0.6815N from the experiment. The maximum punch load for SUS304 stainless steel from the numerical simulation was 1.6495N and 1.7340N from the experiment. In this study, there were two types of springback angles after forming, including springback angle from bottom edge and that from side edge. For rolled copper foil, the springback angle from bottom edge from the numerical simulation was 102.93°, and 103.26° from the experiment, and the springback angle from side edge from the numerical simulation was 101.92°, and 102.44° from the experiment. For SUS304 stainless steel, the springback angle from bottom edge from the numerical simulation was 114.34°, and 112.32° from the experiment, and the springback angle from side edge from the numerical simulation was 113.43°, and 110.86° from the experiment. After forming and springback, the workpiece profiles from both the simulation and the experiment are also consistent. After the comparison between numerical simulation and experimental results, all the errors are within reasonable ranges. It shows that the results of this study can be used as a reference for future research regarding micro-forming.