On the Investigation of a Sustainable Two Step Laser-Based Surface Treatment for the Functionalization of Additive Manufactured Ti-6Al-4V Components

Additive manufacturing innovates component production in industries like healthcare and aerospace due to its ability to create complex geometries, reduce waste, and enable on-demand manufacturing. Despite its advantages, the fabricated components often present high surface roughness, impacting the mechanical properties and functionality of the parts while also negatively influencing postprocessability, e.g., for functionalizing their surfaces by texturing micro/nano structures. This study presents the development of a two-step process for surface smoothing and microstructuring, combining laser polishing (LP) and direct laser interference patterning (DLIP). Ti-6Al-4 V coupons are fabricated with different building orientation angles (BOA) and later polished using a continuous wave laser. Strong influence of the BOA on the initial surface roughness is observed; the LP reduces roughness from 31 μm to ≈1.7 μm. Once the surface is sufficiently smooth, DLIP is used to create line-like microstructures. Structures obtained with nanosecond pulses show higher aspect ratios (≈1.0) compared to the fabricated using picosecond pulses (≈0.5). In both cases, high homogeneity values are reached (>85%-90%). Finally, a new approach for evaluating the performance of the process in terms of energy consumption and structural parameters of the produced patterns is presented, denoting the advantages and disadvantages for each case.