Phase constituent control and correlated properties of titanium aluminide intermetallic alloys through dual-wire arc additive manufacturing

Abstract

TiAl intermetallic compounds were deposited using in-situ alloying with the dual-wire arc additive manufacturing method, and their material properties were investigated. The compounds were designed with different phase constituents and microstructure, achieved through adjusting the elemental wire feed rates according to atomic ratios of Ti: Al = 65%: 35%, 55%: 45%, and 45%: 55%, respectively. Single α2-Ti3Al and γ-TiAl phases were obtained with compositions of Ti-35%Al and Ti-55%Al, while Ti-45%Al resulted in the phase composed of γ-TiAl and α2-Ti3Al. Additionally, the influence of phase composition and microstructure on mechanical properties and oxidation behaviour of the fabricated materials were studied and analysed. In conclusion, the phase composition of TiAl intermetallic alloys could be readily controlled using the dual-wire WAAM method and acceptable properties could be obtained.