Laser surface modification and polishing of additive manufactured metallic parts

The combination of additive manufacturing (AM) and subsequent laser polishing is a technical approach with high flexibility in comparison to conventional processes. AM parts often present the need of post-processing due to surfaces with roughness higher than the admissible for most applications. The laser polishing consists in ablation and melting of a small amount of material, through laser irradiation, which is redistributed to create a surface with low roughness and probably new functionalities. Besides the flexibility, laser polishing presents high processing speed and capability for localized surface treatment. In this study, the resulting characteristics of AM parts irradiated by laser sources with different technical features are investigated and discussed. The parameters applied were the pulse duration, scan speed, repetition rate and average laser power. To evaluate the impact of laser processing on the material the microstructure and surface roughness were analysed and correlated to the process parameters.