Microstructural Evolution And Corrosion Behavior Of Ti-6al-4v Alloy Fabricated By Laser Metal Deposition For Dental Applications

In this study, microstructural evolution and corrosion behavior of Ti-6Al-4V (TC4) alloy fabricated by laser metal deposition (LMD) were investigated in simulated saliva at 37 degrees C as a function of scanning strategies. One-way scanning possessed a higher corrosion resistance than cross-scanning, but both of those were inferior to the wrought one. Compared with conventional wrought counterpart, the higher content of b phase improved the corrosion resistance. Results of MotteSchottky and potentiostatic tests indicated that the passive film upon the surfaces of all the samples exhibited an N-type semiconductor structure and instantaneous nucleation. Of these, the LMD-ed parts displayed a lower donor concentration, higher vacancy diffusion coefficient, and thicker passive film than the wrought samples. XPS analysis revealed that the double-layer structure of passive film leads to a dense protective layer on the surface while the oxide contents of the three were different. (C) 2021 The Authors. Published by Elsevier B.V.