International Journal of Advanced Manufacturing Technology, vol.128, no.1-2, pp.845-860, 2023 (SCI-Expanded)
Additive manufacturing (AM) offers high design flexibility to produce complex parts, particularly in the powder bed fusion process. However, the use of powder as raw material results in poor surface quality as a major defect. To address this, laser polishing (LP) treatment has gained much industrial interest due to its ability to reduce surface roughness. This research paper investigates the effects of laser parameters on surface morphology, surface integrity, microstructure, and microhardness behavior during the LP process. Specifically, LP was applied onto the surface of Ti-6Al-4V samples produced using the powder bed electron beam melting (EBM) process. After laser polishing, roughness values (Sa, Sq, and Sz) were reduced by 87.5%, 87.8%, and 80%, respectively. Additionally, microstructure and microhardness analyses showed that the typical lamellar (α + β) structure in the as-built product transformed into an acicular (α') structure with the effect of LP. Microhardness values increased by 12.5% on the polished surface, and numerical analysis was performed to validate the LP process.