Surface Polishing for Additively Manufactured Titanium Bone Scaffolds to Improve Osseointegration
This research focuses on the porous design, metal additive manufacture and surface polishing methods of Ti6Al4V alloy scaffolds for bone implants and tissue regeneration, with varying lattice structures and pore sizes in the range of 250-350 microns using a selective laser melting (SLM) system Renishaw AM400. Lack of fusion in additive manufacturing results in partially sintered metal particles on both interior and exterior surfaces of porous titanium scaffolds, which necessitates the investigation of seeking an effective polishing method for removing the partially melted particles on the surface of an intricate designed porous implant to achieve a better surface morphology and roughness that augments osseointegration. In this paper, three polishing methods were examined. The experimental result shows that the electropolishing method is capable of effectively removing the incompletely fused particles but it is noteworthy that the parameters controlled during the experiment are crucial to preserve the lattice structure. Rotary abrasive flow polishing method is worth investigating in depth, if better control the direction and rate of flow, the better surface morphology and roughness can be achieved. Lastly, the ultrasonic polishing method was explored to investigate the dependence on the vibratory amplitude control.