Abstract
We demonstrate the formation of permanent and iridescent colors on aluminum, copper, steel, and brass surfaces using femtosecond laser-induced periodic and non-periodic nanostructuring. We show that both the permanent and iridescent colors of the metal surfaces can be erased and re-colored using a second stage of laser processing. A correlation was found between the spectral reflective properties of the laser-processed surfaces and their wettability properties. Transition from superhydrophilic to superhydrophobic response is observed while tailoring the optical reflectance of the metal surfaces. We employ a high power femtosecond fiber laser at 150 kHz repetition rate, which notably reduces the processing time, making this technique attractive for practical applications.
Highlights
Laser-induced structuring has become a versatile technique to modify the surface properties of various materials
We demonstrate how a superhydrophobic aluminum surface can be developed by femtosecond laser processing when stored in vacuum for several hours after the laser treatment
Scanning electron microscope (SEM, TESCAN Vega 3) images show that all angle-dependent colors were features of the periodic structures imprinted on the surface of each metal (Figure 3)
Summary
Laser-induced structuring has become a versatile technique to modify the surface properties of various materials. The developed structure change of the material surface absorption [25] which is the main reason behind the coloration, while the generated colors do not change with a viewing angle [26,27] Another application of laser-induced surface modification is the control of the wettability response of metallic surfaces, which is currently a topic of growing interest in the laser processing of materials [8,28]. Once a robust methodology of laser-matter interaction at these high pulse repetition rate conditions is developed, the processing time of coloring and wettability modifications can be decreased by orders of magnitude, which will make it attractive for industrial applications. In this work we used 150 kHz laser for LIPSS formation and describe methods here for optimizing such a high pulse repetition rate regime of the laser-matter interaction that leads to modifying the coloring and wettability properties of the developed surfaces. We demonstrate how a superhydrophobic aluminum surface can be developed by femtosecond laser processing when stored in vacuum for several hours after the laser treatment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
