ABSTRACT
Directed energy deposition (DED) has been widely used for high-quality cladding of components used in aviation, automotive, biomedical implants, nuclear, and oil and gas industries. It is performed by depositing a single track adjacent to each track, resulting in a wavelike topology that is further machined to acquire a smoother surface. Stellite-6 is widely used for cladding due to its high resistance to wear and corrosion. The machinability of Stellite-6 is lower due to its high hardness and lower thermal conductivity. Its conventional machining incurs additional costs of expensive cutting tools and cutting fluids. Micro-plasma transferred arc (μ-PTA) originated from a tungsten electrode inside the nozzle, resulting in a fine, focused arc with high-energy density and stability at a lower current, a minimal heat-affected zone, and minimal distortion. Considering these features, a μ-PTA-based polishing (μ-PTAbP) was explored and investigated to evaluate the effects of polishing on microstructure, microhardness, wear resistance, and surface morphology. The study revealed that surface quality improved significantly, and the microstructure was refined after μ-PTAbP. The study also showed enhancement in microhardness and wear resistance of the clad surface after μ-PTAbP. It can be inferred from the study that μ-PTAbP is appropriate for sustainable polishing of the DED-based cladded parts.
