The Effect of Laser Powder Bed Fusion Build Orientation on Corrosion Behavior of 316L Stainless Steel, Ti6Al4V‐ELI, and CoCrW Alloy in Simulated Body Fluid, Saliva, and Dulbecco's Modified Eagle Medium Solutions

The corrosion behavior of three biomedical alloys namely 316L SS, Ti6Al4V, and CoCrW manufactured by laser powder bed fusion (LPBF) was systematically investigated relative to build orientation in three different environments, specifically artificial saliva, simulated body fluid, and Dulbecco's Modified Eagle Medium. The main objective of this work was to investigate the effect of building orientation (0, 45, and 90) on the surface properties and electro‐chemical behavior under physiological conditions. X‐ray diffraction analysis showed that increasing build angles led to a reduction in peak intensity and slight shifts in diffraction angles, attributed to cooling dynamics and residual stresses. Surface wettability, evaluated through contact angle measurements, varied significantly with orientation, suggesting changes in surface energy. Surface roughness analysis by 3D profilometry revealed the highest values at 0° due to the staircase effect and powder particle adherence. Electrochemical tests, including open circuit potential and cyclic potentiodynamic polarization, demonstrated that corrosion resistance was orientation‐dependent, with 0° samples generally exhibiting more noble behavior. Scanning electron microscopy observations confirmed this trend by showing increased salt deposition and pitting corrosion in samples fabricated at steeper angles. These results demonstrate that building orientation significantly affects the corrosion behavior of LPBF‐fabricated alloys.