Precision Micromassive Forming of Microgears at Different Temperatures

The precision micromassive forming of microgears was performed at different temperatures with the combination of wire electron discharge machining and precision forging. Microgear molds with 0.1-, 0.2-, and 0.4-mm modules and 12 teeth were fabricated with SODICK, AP250Ls, WEDM software, respectively, at a dimensional tolerance of ≤ 2.5 μm and surface roughness below 280 nm. The precision forging of microgears was investigated on T2 copper with the combination of simulation and experiment. The middle part was filled first, followed by the upper end and, finally, the bottom end. It was quite difficult to form microgears that meet the quality requirements at normal temperature. However, such a problem does not exist at 773 K, and the forming force required was only 36.4% as large as that at room temperature. Microgears formed with the high-temperature forging method exhibited high precision, and the dimensional tolerance was reduced from -38.8 μm of room temperature forging to + 0.9 μm, and the surface roughness was about 300 nm.