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

摘要

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 alpha(2)-Ti3Al and gamma-TiAl phases were obtained with compositions of Ti-35%Al and Ti-55%Al, while Ti-45%Al resulted in the phase composed of gamma-TiAl and alpha(2)-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. (C) 2019 Elsevier B.V. All rights reserved.