Hypo-toxicity and prominent passivation characteristics of 316 L stainless steel fabricated by direct metal laser sintering in a simulated inflammation environment

3D-printing is an emerging technology that challenged wrought counterparts by one-step manufacturing for complicated biological devices. However, the material properties and surface features due to manufacturing parameters play an important role on the corrosion behaviour and influence the toxicity of the material as an implant. In this paper, the improvement of pitting potential was observed by electrochemical experiments as the result of grain refinement of DMLS 316 L at 200 W laser power. The ICP results verified the supressed release of toxic cations after the formation of the passive film with enhanced characteristics. However, the pores from DMLS 316 L have the potential to develop into pits when polarised above pitting potential, promoting the risk of using 3D-printed 316 L as implant materials.