Hybrid forging processes of micro-double gear using micro-forming technology

Micro-gear is an important actuating component used widely in micro-electromechanical systems (MEMS) devices. Forming and assembly technology of micro-parts are urgently needed to be developed. In this paper, novel hybrid processes combining isothermal enclosed forging process with two kinds of piercing methods have been presented to manufacture the micro-double gear. The metal flow and filling quality were studied with finite element (FE) simulation. The results show that the hybrid forging process with central piercing method can improve the defects (underfill and declining shaft) generated by double-ended piercing method. Based on FE analysis, the experiments of hybrid forging process was investigated with central piercing method and the micro-double gear was manufactured with good quality. The results show that central piercing method can solve the shortcoming of inclining shaft with double-ended piercing method. The hybrid forging process is an appropriate technology for manufacturing the micro-double gear.