Research On Formation And Properties Of Zr-based Metallic Glass Micro-gear

As an important part of the MEMS devices, micro-gear is currently developing to thedirection of complication and miniaturization, and the reliability problems of its structurewould emerge with its trend to be smaller and more precision. Metallic glass shows greatapplication prospect in the field of micro-nano fabrication owing to its excellent properties.This article focuses on the Zr-based metallic glass to research its superplastic formingprocess. We tested the property of micro-gear and achieve high-speed rotation andassembly of micro-gear chain under micro-meter scale. The main contents are as follows:(1) At220K/min heating rate, we investigated the best temperature range for Zr-based metallic glass forming process and the effects of dwell time on strain. According tothe statistical experiment, we analyzed the break reason of silicon mold and got aconclusion that the break probability can be reduced by using fixture. Then the micro-gears with clear and complete profile were formed and remained amorphous state. Inaddition, we designed the overlay process and manufactured the two layer gear.(2) In order to verify that the morphology of micro-gear can satisfy using request, itsthickness, end face tilt angle and surface roughness were tested using confocal microscopy.The hardness and Young’s modulus of gear were measured using nanoindentationtechnology. From the load-displacement figure, we drew a conclusion that micro-gearwould be easier to deform under high loading rate.(3) Powered by a micro-stepping motor, the three degrees of freedom micro-platformwas established to build mesh system between drive gear and micro-gear chain. Underhigh-speed, the wear condition of micro-gear was observed after rotation for10h and100h.After the micro-gear system running1h, we compared the energy spectrum of lubricantsof different mesh system and carried out the impact test to verify the excellent mechanicalproperties of metallic glass micro-gear.In this paper, the forming process of Zr-based metallic glass was studied and theproperties of micro-gear were tested. The micro-gear system which was able to run for along time under high speed was assembled, thus can be helpful for promoting theapplication of micro-gear in the field of micro-nano manufacture.