Additive texturing of metallic surfaces for wetting control

Additive manufacturing (AM) has enabled the realization of custom products with intricate geometric features that are either too complex or even intractable for subtractive manufacturing processes. On the other hand, owing to their relatively poor roughness, functional surfaces generated in AM have to be often finish machined. This research explored the prospect of turning this limitation around by pursuing a novel concept of additive texturing (AT) wherein the topography of an AM part is tailored in-process to entail textures that further enhance the functionality of an AM product. In this context, the limits of the selective laser melting process in printing metallic surface microfeatures were investigated as a precursor to realizing texture patterns comprising pillars, channels, and re-entrant structures. Following on from this, the efficacy of such textures in controlling the wetting behaviour of stainless steel AM surfaces was examined. The notion of AT is demonstrated in terms of its capability to generate hydrophobic AM surfaces with water contact angles exceeding 140°.