A simple, inexpensive and environmental-friendly electrochemical etching method to fabricate superhydrophobic GH4169 surfaces

GH4169 is a nickel-based superalloy that has been widely used in aerospace, nuclear energy, petroleum industry and extrusion molds due to its excellent strength, weldability and long-term stability. To improve its self-cleaning and anti-icing properties in consideration of its broad applications in aerospace and aviation, we developed an electrochemical method using neutral electrolyte, followed by low surface energy treatment to fabricate superhydrophobic GH4169 surfaces. The superhydrophobic surfaces prepared in sodium nitrate and sodium chloride solutions had contact angles of 159.6° and 160.7°, and sliding angles of 7.65° and 7.8°, respectively. Their surface wettability is highly dependent on current density and process time in electrochemical etching whereas the concentration and temperature of the electrolyte are not so important. The prepared superhydrophobic GH4169 surfaces demonstrate anti-adhesion, self-cleaning and anti-icing properties.