Localized Electrochemical Deposition of Ni Microstructure With 3D‐Printed Solution Flow‐Type Microdroplet Cell

Electrochemical additive manufacturing (ECAM) of metal parts directly on metallic substrates using low‐cost techniques has recently attracted considerable attention. In this work, a solution flow‐type microdroplet cell (SF‐MDC) technique was employed to fabricate Ni dots, lines, rods, and wires on a localized Cu substrate. The effect of deposition electrolyte pH and temperature on the crystallographic orientation and surface morphology of the deposited Ni was investigated. The top deposited Ni layer surface image, morphology, crystal structures, and chemical composition were analyzed using optical microscope, scanning electron microscope, X‐ray diffraction, and energy‐dispersive X‐ray spectroscopy, respectively. The results showed that at a lower electrolyte pH of 1.5–2.0, several defects and pits were observed, while a smooth, small‐grained, and bright Ni surface was obtained at a pH of 3.5. When the deposition pH increased to 6.5, significant cracks were observed on the deposited layer. The crystallographic texture of the Ni layer is primarily governed by preferential growth in the (200) plane. The height of the Ni deposit increased from 5.6 to 24.5 µm as the substrate temperature was raised from 20 to 60 °C. The SF‐MDC technique enables precise control over the shape and size of Ni microstructures during fabrication.