Hybrid Finishing of the Additively Manufactured Tubular Lattice Structure for Medical Application

Additive manufacturing (AM) has shown great potential in creating lattice structures with unique mechanical properties that are difficult to achieve through traditional manufacturing processes. However, the intrinsic surface defects in AM lattice structures can have a significant impact on their properties, including inferior mechanical strength, reduced specific energy absorption, and fatigue life. Therefore, it is essential to improve the surface quality of AM lattice structures to ensure their optimal performance and reliability. Existing finishing methods such as sandblasting, chemical etching, and electrochemical polishing may encounter problems such as inaccessibility to the internal lattice surfaces, uneven removal, or environmental issues. The finishing of lattice structures poses a unique set of challenges due to the fragility of the thin structures and the limited accessibility of conventional finishing tools. Hence, this paper aims to develop a novel hybrid finishing method for AM tubular lattice based on magnetic abrasive finishing and dry electrochemical polishing. Results have shown that the surface finish can be improved by more than 70% and the resultant surface is free from the major defects including the partially bonded particles and staircase effect. This study advances the surface finishing techniques of AM complex structures and provides an alternative post-processing method for the AM industry.