Surface finishing of laser powder bed fusion AlSi10Mg lattice structures by electrochemical polishing

Additive manufacturing (AM) of AlSi10Mg lattice structures have high surface quality requirements in practical applications, which limits their application. This paper employs the electrochemical polishing (ECP) method to effectively enhance the surface quality of AlSi10Mg lattice structures while minimizing deformation and material removal. The influence mechanism of different process parameters on the surface roughness and material removal amounts of the samples during ECP was analyzed. Under the optimized ECP process conditions, the surface roughness of the samples was reduced by 82.6%, and the polishing effect was good. The ultrasonically-assisted electrochemical polishing (UA-ECP) method was adopted, utilizing the synergistic effects of cavitation and electrochemical reactions to address issues in traditional ECP, such as insufficient electrolyte permeability and concentration differences between the internal and external regions of the structures due to complex lattice structures, as well as the hindrance to continuous and uniform reaction progresses caused by Si-containing reactants covering the sample surfaces. This method further improves the surface quality of samples and effectively enhances the efficiency of ECP. Research results demonstrate that the mechanical-electrochemical synergy has significant potential in improving the surface quality of AM complex structures.