Localized electrodeposition process and mechanical properties of complex structures

In the field of micro/nano manufacturing, high-precision fabrication of miniature pure metallic components with a characteristic size of 5 µm constitutes a critical demand for the development of advanced microelectronic and biomedical devices. In this work, the potential window for copper electrodeposition was determined as − 0.1 to − 1 V by electrochemical characterization. Subsequently, complex cantilevered pure copper microstructures were directly fabricated without masks or supporting structures using localized electrodeposition-based micro-additive manufacturing (LECD-µAM), verifying the universality and applicability of this technique. To clarify the mechanical properties and strengthening mechanisms, micro-tensile tests and transmission Kikuchi diffraction (TKD) were employed for characterization. The results reveal that the as-fabricated pure copper microstructures achieve a yield strength of 440 MPa. The interior exhibits an ultrafine grained microstructure with an average grain size of 557.7 nm and an initial aspect ratio of 1.53:1. In the micro-tensile deformed region, grains present an elongated morphology with a size increase of up to 133.4%. Microscopic mechanism analysis indicates that the high strength of the microstructures originates from the synergistic effect of grain refinement strengthening and interfacial strengthening.