Laser-Enabled Carbon Dot Coating for Powder Bed Fusion Metal Parts

The development of environmentally friendly surface engineering techniques for 3D-printed metal parts is crucial for fluid-related applications. This study introduces two innovative, PFAS-free methods to achieve superhydrophilic surfaces on laser powder bed fusion (L-PBF) fabricated AlSi10Mg and Ti6Al4V samples. The first method involves the direct application of gel-like carbon dots (G-CDs) coating inducing superhydrophilicity. The second method integrates nanosecond laser texturing to create microgrooves that facilitate capillary-driven liquid transport, followed by G-CDs coating, resulting in a stable superwicking surface. This laser-based method also offers precise control over fluid direction by adjusting the orientation of the microgrooves, allowing the surface to be designed with programmable wicking paths. Both methods maintain a water contact angle below 10° for over 30 days. Surface features, surface chemistry, wettability, wicking behavior are measured on AlSi10Mg and Ti6Al4V samples through Scanning Electron Microscopy (SEM), Electron Dispersive Spectroscopy (EDS), contact angle goniometer, and high-speed camera, respectively.