Manufacturing of micro components on amorphous alloy with a high-aspect-ratio characteristic structure by multistage forming method

Amorphous alloys are considered as an ideal material for complex micro component fabrication due to their extraordinary mechanical properties and thermoplastic formability. However, the conventional theories and thermoplastic forming (TPF) methods for amorphous alloys require a lower loading rate and a higher pressure which extremely prolong the processing time and reduce the mold life. In this study, an efficient and low-cost TPF-based method is developed to fabricate the micro impeller by controlling flow states of amorphous supercooled liquid at different forming stages. Based on the finite element simulation results of the filling process and strain distribution, the new multistage forming method enables thin-walled blade fabrication without a significant “dead zone” by adjusting the velocity gradient of the flow front, thus reducing the pressure requirement. Also, the non-Newtonian flow region is proved to be an appropriate TPF window at high temperatures. To verify the validity of the multistage forming method, technological experiments undergoing different conditions were performed. Finally, the full-filled thin-walled blades with a width of 508 μm and surface roughness of 0.25 μm were prepared in about 50 s. This research demonstrates a new TPF-based method for the rapid fabrication of micro components with a high-aspect-ratio characteristic structure in an economic way.