Peculiar microstructural evolution and tensile properties of β-containing γ-TiAl alloys fabricated by electron beam melting

The microstructure and tensile properties of β-containing Ti–44Al–4Cr alloy rods additively manufactured by electron beam melting (EBM) process were examined as a function input energy density determined the processing parameters. To best our knowledge, this is first report to demonstrate that two types fine microstructures have been obtained in γ-TiAl alloys varying during EBM process. A uniform α2/β/γ mixed structure containing an α2/γ lamellar region β/γ dual-phase formed at high conditions. On other hand, lower leads formation peculiar layered perpendicular building direction, consisting ultrafine grain layer layer. difference originates from solidification temperature distribution melt pool, which are dependent on density. Furthermore, it was found strength closely related volume fractions β phase grains massive α rapid cooling under low with amounts these exhibit comparable higher than conventional room 1023 K, respectively.