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

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.