Laser-based surface modification and its influence on the topography and wettability of a new additively manufactured aluminum-based alloy

Additive Manufacturing methods enable the fabrication of complex 3D components for a wide range of applications, ranging from prototyping up to part manufacturing in industrial several sectors including aerospace and medical industries. In particular, the surface quality of these parts have to be improve in order to reach standard qualities or to obtain specific surface functions. In this frame, this research work reports on laser-based surface finishing treatments of additive manufactured specimens consisting on a new innovative aluminum-alloy (Scancromal®). The experiments are performed with a picosecond pulsed-laser system operating at a fundamental wavelength of 1064 nm, aiming the fabrication of functionalized surfaces with improved properties through topographical features in the micrometer range. To characterize the surface topography, the specimens are analyzed using Confocal Microscopy (CM) and Scanning Electron Microscopy (SEM). Contact Angle measurements are used for the determination of wetting and icing-repellent characteristics of lasertreated AM substrates. Additionally, surface free energy (SFE) is determined and compared with the reference samples. The results show a significant influence of the laser treatment on the surface quality of the treated samples and its resulting wettability behavior. For instance, the water contact angle (WCA) could be increased from 62° to 134°, while the freezing time is also increased from 11 to 25 s after laser treatment, which can be an advantage for some applications and extend the feasibility of AM components beyond the current state of the art.