Rapid fabrication of near superhydrophobic aluminium surface through nanosecond laser texture and heat treatment

Abstract

Controlling surface wettability inspired by nano structure of lotus leaf has attracted much attention. The superhydrophobicity on the metals is significant for the applications including water repellence, self-cleaning, anti-corrosion, and reduction of drag. Herein a near superhydrophobic surface of 5051 aluminium has been fabricated by employing a combination of nanosecond laser texture and heat treatment, without using any toxic chemicals. The aluminium surface was textured by fibre nanosecond laser and then heat treated at 150 °C to create the near superhydrophobic surface. The evolution of heat treatment time with respect to contact angle measurements has been investigated. The contact angle became 0° when processed by two different kinds of laser textures (sinusoid pattern and grid pattern). The influence of heat treatment on the wettability of the laser textured aluminium surface was studied. The contact angle exhibits 134.88° and 136.97° for sinusoidal pattern and grid pattern with 72 hours heat treatment, respectively. The mechanism for fast wettability conversion time is discussed. This method is a rapid and environment-friendly process, which is feasible for fabrication.

Organic Matter Transfer Caused by Concentration Difference Creates TC4 Surfaces with Switchable Wettability

“…In this study, heat treatment was employed to switch the wettability of electrochemical processing surfaces. Many studies have been performed on the switchable wettability of metal rough surfaces and generally suggest that heat treatment accelerates the adsorption of organic matter in the air to switch the surface wetability. ,, However, bidirectional organic matter transfer, not only unidirectional adsorption, is regarded as the reason for the reversible wettability switching of metal rough surfaces in this study. Besides surface structure, roughness, and oxide content, the concentration difference of organic matter, which has not been mentioned before in other research, is also crucial to the organic matter transfer.…”

“…Many studies have been performed on the switchable wettability of metal rough surfaces and generally suggest that heat treatment accelerates the adsorption of organic matter in the air to switch the surface wetability. 32,34,35 However, bidirectional organic matter transfer, not only unidirectional adsorption, is regarded as the reason for the reversible wettability switching of metal rough surfaces in this study.…”