Improvement of the surface quality of titanium-based design objects produced through WAAM technology using chemical machining: A preliminary study

The quality of the surface is one of the most important factors in the fabrication of a component via additive manufacturing (AM). In particular, when considering the manufacture of workpieces in titanium and its alloys the successful use of surface treatments is essential. In fact, many fracture-related events, in particular fatigue cracks, start near the surface of the component. Numerous techniques based on machining, shot peening, or laser polishing have been proposed to enhance the surface quality. The limitations of these treatments stem from the challenges posed by focusing on complex form components. One of the most promising approaches for achieving homogenous smoothing of intricate objects with internal channels and lattice structure continues to be chemical-based surface treatments. It is a pivotal method to remove material that has been polluted by oxygen during processing. In this instance, the resistance to crack initiation and fracture is fundamentally improved by the removal of a hard, brittle top layer. In this work, HF/HNO3-based treatment tailored for 3D printed design products is presented.