Influence of open area ratio on microstructure shape in Cu–Ni alloy electrodeposition

Abstract

This research experimentally analyzed the influence of the open area ratio (OAR) on the formation and growth of the microstructure in Cu-Ni alloy electrodeposition. The OAR was controlled by changing the pitch of circular patterns with a diameter of 20 lm. For an OAR higher than 20 %, the electrodeposited structures grew vertically in pillar-like formations. As the OAR was decreased from 100 to 20 %, the density, height, and width of the structures increased. In addition, in this OAR range, the structures formed along the edge area of the circular patterns. In contrast, for an OAR lower than 10 %, dendrite structures were generated. The electrodeposited structures were coated with a hydrophobic plasma-polymerized fluorocarbon (PPFC) layer. In the electrodeposited sample without circular patterns (OAR = 100 %) with an OAR smaller than 1.25 %, the measured contact angles were almost the same as the contact angle (107°) measured from the flat surface without electrodeposition. In contrast, the samples with an OAR range of 2.5-50 % were modified to be superhydrophobic, and they demonstrated an excellent self-cleaning ability.

Fabrication of Three-Dimensional Microstructure Film by Ni-Cu Alloy Electrodeposition for Joining Dissimilar Materials

“…2 (a), the Cu element was detected on the dendrites and trunk, while the Ni element was mainly detected on a plate surface and the root part of the dendritic-type electrodeposited structure. It has been reported that when the Ni-Cu alloy plating solution contains a low Cu concentration and a high Ni concentration is electrodeposited, Cu electrodeposition contributes mainly on the convexity and grows in a dendritic shape [15]. The reason is that Cu electrodeposition obeys the diffusion-limited growth mode and thus Cu ions are first reduced at the upper tip which is the shortest diffusion distance from the bulk solution.…”

“…It has known that the three-dimensional microstructure films can be deposited by Cu [9], Ni [10,11] and Ni-Cu [12][13][14][15] alloys electrodepositions. In this study, the Ni-Cu alloys that can form various shapes were focused.…”

“…In this study, the Ni-Cu alloys that can form various shapes were focused. The previous studies have reported the three-dimensional microstructure films using Ni-Cu alloys plating solutions that contain low concentration Cu ion and high concentration Ni ion [12][13][14][15]. However, it has not yet been clarified that the cross-sectional shape and microstructure of the electrodeposited films when the concentrations of Ni amidosulfate and Cu sulfate, and the plating current density (C.D.)…”

Growth Mechanism and Application of Nanostructures Fabricated by a Copper Sulfate Solution Containing Boric Acid

“…The dendrite structure can be fabricated when the electrodeposition process is highly controlled by diffusion of the ions. 31 If the Cu ion diffusion rate was low and the applied current density excessively increased, the Cu ion would be dominantly deposited at the edge of the electrodeposited structure instead of at the defect originating from a screw dislocation. Therefore, dendrite structures were formed with 0.1 M CuSO 4 • 5H 2 O and an applied current density of 70 mA/cm 2 .…”

Dialectical Observation of Controllable Electrodeposited Ni Nanocones: the Unification of Local Disorder and Overall Order

“…Nanostructured metals with unique surfaces [1] were widely used in a variety of fields, such as surface modification [2], ultra-hydrophobic layers [3][4][5], supercapacitors [6], microelectronic interconnection [7], nanoprobes [8], solar cells [9], gas sensors [10,11], catalysts [12][13][14][15][16][17][18][19], mechanical polishing slurries [20], diamond wheels [21], nanoscale precision surfaces [22,23]. As a result, many preparation techniques of nanostructured metal surfaces had been proposed, including hydrothermal method [10,11], sol-gel method [24], template method [25], chemical vapor deposition method [26], chemical reduction method [27], and microemulsion method [28].…”