Proceedings of the
World Congress on Micro and Nano Manufacturing (WCMNM 2022 )
19–22 September 2022, Lueven, Belgium
doi:10.3850/978-981-18-5180-3_RP35-0026
Influence of Initial Roughness on Laser Ablation of AA7075 Alloy and its Wettability Transition
1Advanced Materials Processing Research Group, Materials Engineering, IIT Gandhinagar, Gujarat, India
2SMART Lab, Jointly with Mechanical & Electrical Engineering Discipline, IIT Gandhinagar, Gujarat, India
ABSTRACT
Non-wetting/hydrophobic surfaces on aluminium alloy 7075 are becoming desirable for aerospace and automobile applications due to its self-cleaning, anti-icing, anti-fouling and anti-corrosive properties. Laser ablation is a fast and efficient process to create such surfaces using micro/nano-scale textures that aid in wettability transition from hydrophilic to hydrophobic. There is little research on the effects of initial surface roughness on the contact angle of laser ablated AA7075 surfaces. This study uses a microsecond laser to create textures on AA7075 with various initial surface roughnesses. All the freshly laser textured surface transitioned from superhydrophilic to hydrophobic surface after vacuum annealing. The static contact angle of the surfaces was studied with respect to surface morphology and roughness. It was observed that the initial surface roughness resulted in quasi-superhydrophobic surfaces for all the specimen except the one with most roughness.
Keywords: Aluminium Alloy, Hydrophobic, Laser texturing, Roughness.
1Advanced Materials Processing Research Group, Materials Engineering, IIT Gandhinagar, Gujarat, India
2SMART Lab, Jointly with Mechanical & Electrical Engineering Discipline, IIT Gandhinagar, Gujarat, India
ABSTRACT
Non-wetting/hydrophobic surfaces on aluminium alloy 7075 are becoming desirable for aerospace and automobile applications due to its self-cleaning, anti-icing, anti-fouling and anti-corrosive properties. Laser ablation is a fast and efficient process to create such surfaces using micro/nano-scale textures that aid in wettability transition from hydrophilic to hydrophobic. There is little research on the effects of initial surface roughness on the contact angle of laser ablated AA7075 surfaces. This study uses a microsecond laser to create textures on AA7075 with various initial surface roughnesses. All the freshly laser textured surface transitioned from superhydrophilic to hydrophobic surface after vacuum annealing. The static contact angle of the surfaces was studied with respect to surface morphology and roughness. It was observed that the initial surface roughness resulted in quasi-superhydrophobic surfaces for all the specimen except the one with most roughness.
Keywords: Aluminium Alloy, Hydrophobic, Laser texturing, Roughness.
