Fabrication of hierarchical dual structured (HDS) nickel surfaces and their corrosion behavior

In this study, at first by using a single stage electroplating, the superhydrophobic surface with hierarchical dual structured (HDS) is fabricated by 3 different fatty acids. It can be seen that the addition of myristic acid to NiMn bath fabricates the hierarchical structure which causes the superhydrophobicity property and brings the contact angle up to 160° which leads to a very high corrosion resistance of 0.005 mpy. The specimen that contains myristic acid has reduced the corrosion current density about two decades. In the second part of the study due to outstanding performance in myristic acid to create superhydrophobic properties as well as improved corrosion resistance, the single-stage continuous constant flow electroplating method is converted to two and four stage method. Its effect on improving the corrosion was investigated. In terms of wettability, increasing the number of stages of electroplating fabricates more ordered hierarchical dual structured (HDS) which improves contact angle. From this point although all samples have the contact angle greater than 150°, but the 4-stage sample has outperformed the other specimens. But in terms of corrosion by increasing the number of electroplating stages, corrosion improvement is not necessarily observed.