Superhydrophobic Surface Preparation and Wettability Transition of Titanium Alloy with Micro/Nano Hierarchical Texture

Abstract

Microstructures are applied to various hydrophobic/hydrophilic surfaces due to the role of adjusting the surface wettability. In this paper, a 1064 nm pulsed picosecond laser was applied to prepare a micro/nano hierarchical structure on the surface of the titanium alloy (Ti-6Al-4V). The microstructures consist of dimple arrays with various diameters, depths, and areal densities. They are obtained by controlling the pulse energy and the number of pulses. The nanostructures are periodic ripples, which are defined as laser-induced periodic surface structure (LIPSS), and the dimensional parameter of LIPSS can be adjusted by changing the laser energy density and scanning speed. The contact angles of various laser textured surfaces were measured. It is found that the contact angle increases with the density of micro-textured surface increases, and the wetting state of textured surfaces conforms to the Cassie model. Some laser processed samples were subjected to low-temperature annealing treatment. It is observed that the low-temperature annealing process can accelerate the surface wettability transition significantly, which is attributed to the change of the hydroxyl groups on the surface. Finally, a superhydrophobic surface with the maximum contact angle of 144.58° is obtained.

A Post-Treatment Method to Enhance the Property of Aerosol Jet Printed Electric Circuit on 3D Printed Substrate

“…Further research has shown that the presence of common atmosphere gases such as CO 2 , O 2, and N 2 is not the main reason causing the carbon concentration changes, instead, the absorption of organic compounds seems to have a more significant influence on the carbon concentration [ 52 , 53 ]. These further supported with other research works showing that immersion or store in organic rich media will accelerate the carbon absorption process as in [ 44 , 54 , 55 , 56 ]. It seems the organic contamination during the annealing process could be the most possible reason.…”

“…The amount of silver decreased significantly due to the increase of oxygen and carbon species on the sample surface. The increased carbon concentration and associated nonpolar carbon group formation decreased the surface free energy [ 42 , 43 , 44 , 45 , 46 ]. Generally, the absorption of carbon item from the environment occurs in the long term [ 47 , 48 ], while the annealing process can accelerate the process in a short time [ 45 , 48 , 49 ].…”

Overview of Laser Applications in Manufacturing and Materials Processing in Recent Years

“…14(b). Yang et al [183] used a ps laser to create a hierarchical texture on a titanium alloy consisting of nano ripples superimposed on microdimple arrays that display superhydrophobic behavior. Materials with tailored wetting properties have potential applications in microfluidics, biomaterials, anti-icing, self-cleaning, etc.…”

Fabrication of a Low Adhesive Superhydrophobic Surface on Ti6Al4V Alloys Using TiO2/Ni Composite Electrodeposition

“…Recently, superhydrophobic surfaces on titanium alloys with a water contact angle greater than 150° and a sliding angle lower than 10° have aroused much attention. They can provide widespread utilizations in anti-icing, anti-adhesion, and oil/water separation [ 3 , 4 , 5 ]. Although superhydrophobic surfaces have been proved to be effective in improving the corrosion resistance of titanium alloys, their low hardness, poor wear resistance, and high friction coefficient prevent them from being extensively employed in engineering applications [ 6 , 7 ].…”