Improved corrosion behaviour of electron beam melted Ti-6Al–4V alloy in phosphate buffered saline

• Published in: Corrosion science 2017-07, Vol.123, p.289-296
• Main Authors: Bai, Yun, Gai, Xin, Li, Shujun, Zhang, Lai-Chang, Liu, Yujing, Hao, Yulin, Zhang, Xing, Yang, Rui, Gao, Yongbo
• Format: Article
• Language: English
• Subjects: Alloying effects; Alloying elements; Alloys; Buffers; Charge transfer; Corrosion resistance; Corrosion resistant alloys; Dissolution; EIS; Electrochemical corrosion; Electron beam melting; Microstructure; Passive films; Phases; Polarisation; Titanium; Titanium base alloys
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2017.05.003

•The Ti-6Al–4V alloy is fabricated by electron beam melting (EBM) technology.•The electrochemical corrosion behaviour of EBM-produced Ti-6Al–4V is investigated.•A larger proportions of β phase and ultrafine-grained lamellar α/β phases are observed in the microstructure of EBM-produced Ti-6Al–4V.•EBM-produced Ti-6Al–4V possesses slightly better corrosion resistance than the traditional wrought Ti-6Al–4V. The electrochemical corrosion behaviour of Ti-6Al–4V prepared by electron beam melting was investigated in phosphate buffered saline and compared with those of traditional wrought counterpart. Electrochemical results showed EBM-produced Ti-6Al–4V possesses slightly better corrosion resistance than the wrought Ti-6Al–4V, which is attributed to larger proportions of β phase and ultrafine-grained lamellar α/β phases in the microstructure of EBM-produced Ti-6Al–4V. The β phase enhances the resistance of charge transfer, thereby reducing the rate of metal dissolving reaction; while the α/β phases result in homogenous distribution of alloying elements in different phases thus restraining the galvanic effect between α and β phases.