Fabrication of 3D microstructure with layer-by-layer micro-electric resistance slip welding

A 3D microstructure with a high depth-to-width ratio was fabricated by combining femtosecond laser cutting and micro-electric resistance slip welding. To improve laminated precision and connection strength of every layer 2D microstructure, the layer-by-layer micro-electric resistance slip welding was used for every layer 2D microstructure to obtain a better technological parameters. Under above process parameters, the anti-shear ability of 3D microstructure was tested. The test results indicate that with the number of the slip welding discharges increasing, the yield shear stress of microstructure increases from 8.04 N to 65.97 N. Then, the deposition effect of the tungsten bar electrode produced during layer-by-layer micro-electric resistance slip welding was also studied through the Energy Dispersive Spectrometer (EDS) analysis. Finally, micro array square holes with a size of 50 μm×50 μm and a micro-gear cavity were processed after 160 time's slip welding discharge under a femtosecond laser power of 110 mW, a cutting speed of 50 μm/s, a welding voltage of 0.21 V, welding time of 10 ms, and a welding pressure of 0.2 MPa. The fabrication results show that the 3D microstructures processed by the layer-by-layer micro-electric resistance slip welding have good surface quality and the superposition between the layers of microstructure. Therefore, layer-by-layer micro-electric resistance slip welding can guarantee the connection strength and laminated precision of every layer 2D microstructure.