Microstructure evolution, corrosion behavior, and biocompatibility of Ti-6Al-4V alloy manufactured by electron beam melting (EBM) technique

Abstract

It is the purpose of this study to investigate the effects of heat treatment on the microstructure, corrosion, and biological behavior of Ti-6Al-4V alloy manufactured using electron beam melting (EBM). The EBM parts were exposed to different heat treatments at 1000 °C and various cooling rates (HT-1, HT-2, and HT-3) to obtain a combination of α and β phases. Electrochemical analyses indicate that the non-heat treated alloy (Ref) exhibits superior corrosion resistance during early immersion, while all samples display similar corrosion performance after one month of immersion. The higher corrosion performance was associated with the content of β phases in the manufactured alloy. The Ref, HT-1, HT-2, and HT-3 EBMed alloys had corrosion current densities of 0.46, 0.66, 0.67, and 0.92 µA cm−2, respectively, after one month of immersion. Cell adhesion and durability were shown to be excellent on HT-3 samples. In conclusion, a suitable heat treatment can improve the biological performance of the EBMed alloy, despite resulting in lower corrosion performance in the early stages of corrosion.