Highly effective smoothening of 3D-printed metal structures via overpotential electrochemical polishing

ABSTRACT High roughness of metal structures made by selective laser melting restricted their extensive applications. A strategy of overpotential electrochemical polishing was developed for effectively smoothening three-dimensional (3D)-printed surfaces, particularly for removing sticking particles. Average surface roughness of 0.18？μm was achieved with a small thickness removed of ～70？μm through a combination of overpotential and conventional electrochemical polishing. Interestingly, micro-lattices polished with this approach nearly doubled the specific compressive plateau stress and energy absorption over as-printed lattices. Moreover, the success with 316L stainless steel, 4130 steel and AlSi10Mg, indicates the potential of this approach for smoothening other 3D-printed metals. GRAPHICAL ABSTRACT IMPACT STATEMENT A highly effective technology to smoothen complex and rough 3D-printed metal surfaces is developed using a novel overpotential electrochemical polishing, which can enhance mechanical and functional properties of 3D-printed metals