Laminated fabrication of micro-mold based on WEDM and thermal diffusion welding

A 3D micro-structure with a high aspect ratio was fabricated by combining Wire Electrical Discharge Machining(WEDM) and vacuum pressure thermal diffusion welding. The WEDM and thermal diffusion welding were researched, and the better technological parameters were obtained to fabricate a micro-mold. Firstly, a copper foil with a thickness of 100 μm was cut to obtain a multi-layer 2D micro-structure under the conditions of a pulse width of 10 μs, a pulse interval of 40 μs, a wire cutting current of 0.28 A and a voltage of 60 V. Then, the 2D micro-structure of a multilayer copper foil was fabricated by vacuum pressure thermal diffusion welding under the technological parameters in a thermal diffusion temperature of 850°C, a thermal diffusion time of 10 h and a pressure of 1.0 μPa. The multilayer copper 2D microstructure was connected together by vacuum pressure thermal diffusion welding to fit into a six frustum pyramid mold and gear molds with two-stage steps and three-stage steps, respectively. Experimental results indicate that the 3D micro-mold with good surface quality is an ideal fabrication and fits to design models. Finally, based on ultrasonic powder molding, two-stage and three-stage plastic gears are respectively obtained. These micro plastic parts show good quality, which verifies the feasibility and usability of laminated micro molds. ©, 2015, Chinese Academy of Sciences. All right reserved.