Laser Polishing of Additive Manufactured Superalloy

Laser additive manufacturing has attracted considerable interest as a promising digital manufacturing technology in recent years. However, poor surface quality restricts its practical application. In this paper, we demonstrate the capability of laser polishing in rough surface of additive manufactured Inconel 718 alloy. Both as-received surface and laser-polished surface were analyzed carefully by Confocal Microscope, Scanning Electron Microscopy, Energy Dispersive Spectrometer and X-ray Diffraction. The results revealed that as-received Inconel 718 alloy with surface roughness more than 7 μm could be reduced to less than 0.1 μm through laser polishing (LP) process. Moreover, microstructure, micro-hardness and wear resistance of laser-polished zone were investigated. This preliminary study has shown the potential of laser polishing in improving surface finish and properties of additive manufactured superalloy without damage to the substrate.