Reviewing the class of Al-rich Ti-Al alloys: modeling high temperature plastic anisotropy and asymmetry

Abstract

In the last decades, the class of Ti-rich TiAl-based intermetallic materials has replaced many contemporary alloys till 900°C. Due to higher oxidation resistance, 20% lower density and higher (about 150°C more) operating temperature possibility of Al-rich TiAl alloys over Ti-rich side, phases from the Al-rich region of this alloy system are considered to be highly potential candidates for high temperature structural applications. Although there are a lot of works about Ti-rich alloys, however, investigation from the Al-rich side is very limited. This work reviews the class of Al-rich TiAl alloys in terms of phases, microstructures, morphology, deformation mechanisms, mechanical behaviors along with a possible micromechanical modeling approach. Single crystal like Ti-61.8at.%Al alloy from the Al-rich family has been chosen as an example for modeling high temperature anisotropy and tension-compression asymmetry. A possible comparison with Ti-rich side is also presented.

Reactivity of the Ti–Al system: Experimental study and molecular dynamics simulations

“…Research on Ti-Al based intermetallic alloys is an active research field due to their possible use in aircraft engines, industrial gas turbines, and automotive industries. These materials exhibit unique physical and mechanical properties such as very good strength, high specific yield strength and stiffness, good oxidation resistance combined with good creep properties at high temperatures, low density, high thermal capability and biocompatibility, ... 1 . Actually, titanium aluminides is an important class of materials that could provide a promising alternative to nickel alloys.…”