Additive Manufacturing (AM) has become one of the most revolutionary technology applications in aerospace and medical manufacturing, due to the possibility of fabricating complex parts with near-net-shape and less material waste. Parts that are fabricated using powder-bed fusion method have a relative high initial roughness. This can potentially negatively affect the mechanical performance of the components and also has a negative impact when producing microstructured surface for enhancing other surface functionalities. Post-processing treatment steps are necessary.
This work focuses on the development of a two-step post process consisting of an initial surface smoothing step through laser re-melting polishing (Figure 1a), followed by the fabrication of periodical structures for surface functionalisation using Direct Laser Interference Patterning (DLIP, Figure 1c) [1-3]. Two materials are evaluated, being Ti-6Al-4V and Scalmalloy® (Al-Mg-Sc).

A relevant reduction of the initial surface roughness, from 19.1 µm to 2.6 µm for Ti and from 18.5 µm to 2.5 µm for Scalmalloy, was observed after the laser polishing (Figure 1b). This improvement enabled the use of ps-DLIP to fabricate structures with a period of 6.0 µm (Figure 1d) by adequately changing the processing parameters. High homogeneity values (up to 92 %), as well as structure depths up to ~0.5 µm for Titanium and ~0.4 µm for Scalmalloy were achieved.