In vitro wear, corrosion and biocompatibility of electron beam melted gamma-TiAl

Electron beam melting (EBM), a powder bed fusion based additive manufacturing process, has been used to fabricate Ti-48Al-2Cr-2Nb gamma-TiAl samples. The sampleswere evaluated for their potential use in biomedical applications in terms of in vitro wear, corrosion and biocompatibility in as-deposited (AD) and hot isostatically pressed (HIPed) conditions. The samples were found to exhibit a lamellar microstructure consisting of gamma-TiAl and Ti3Al (alpha(2)) phases in both the conditions. However, their in vitro wear and corrosion performance in Hank's balanced salt solution (HBSS), with and without fetal bovine serum (FBS), was found to be very different. The AD samples exhibited comparable passive behavior to commercially pure titanium (CP-Ti). Their corrosion potentials and currents were better than those of CP-Ti. The gamma-TiAl samples exhibited wear rates of the order of 10(-4) mm(3)/N center dot m in HBSS. The presence of FBS was found to increase the corrosion and the wear rate of this alloy increased by 65%. In vitro cell culture experiments, using NIH3T3 cells, demonstrated that the EBM processed gamma-TiAl is non-toxic and can allow cell adhesion and proliferation as effectively as CP-Ti. (C) 2017 Elsevier Ltd. All rights reserved