Microstructural evolution and corrosion behavior of Ti-6Al-4V alloy fabricated by laser metal deposition for dental applications
By Zhou, Xing; Xu, Dake; Geng, Shujiang; Fan, Yongqiang; Yang, Chunguang; Wang, Qiang; Wang, Fuhui
Published in Journal of Materials Research and Technology
2021
Abstract
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 °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 β phase improved the corrosion resistance. Results of Mott-Schottky 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.