Characterization of titanium aluminide alloy components fabricated by additive manufacturing using electron beam melting

Intermetallic, gamma-TiAl, equiaxed, strian-grain (similar to 2 mu m) structures with lamellar gamma/alpha(2)-Ti3Al colonies with average spacing of 0.6 mu m have been fabricated by additive manufacturing using electron beam melting (EBM) of precursor, atomized powder. The residual microindentation (Vickers) hardness (HV) averaged 4.1 GPa, corresponding to a nominal yield strength of similar to 1.4 GPa (similar to HV/3), and a specific yield strength of 0.37 GPa cm(3) g(-1) (for a density of 3.76 g cm(-3)), in contrast to 0.27 GPa cm(3) g(-1) for EBM-fabricated Ti-6Al-4V components. These results demonstrate the potential to fabricate near net shape and complex titanium aluminide products directly using EBM technology in important aerospace and automotive applications. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.