Unravelling a novel oscillation-loaded dynamic micro embossing process: Experiment and modelling

Authors: Jihui Huang, Zhutian Xu, Jiansheng Liu, Linfa Peng, M. W. Fu

In MSFSSs, there are many integrated structures with different functions and the fabrication of these structures generally required compound technologies. Currently, the dynamic micro embossing of surface structures and additive manufacturing of volume structures were investigated. The characteristics of each process were thoroughly studied, and the fabrication quality control during processing was also discussed in researches.

To make micro structures on general surfaces, an oscillation-loaded DME process, in which the miniature punch with single micro feature oscillates with tunable frequency and amplitude and periodically emboss part surface, is developed. During the embossing, workpiece was fixed to the horizontal sliding platform, so this method can process the workpiece surface with high efficiency at high the frequency. Moreover, the high-frequency oscillation enables the miniaturization of micro features area without much loss of efficiency, which can decrease embossing force and avert the change of geometry. In the investigation, the back part of the micro groove exhibited a deeper sink and a steeper wall. The deformed microstructure, divided into dead zone and shear band, expanded diagonally downward to the back part. Increasing grain size and decreasing punch feature size contributed to enhancing the surface roughening and dimension scatter. Structure depth formability first surges and then declines with the current frequency, which can be facilitated by increasing current amplitude. Raising current amplitude is effective to improve the structure depth formability at high current frequency.