Microstructural effects on tensile properties of cast TiAl–Fe–V–B alloy

A gamma titanium aluminide, Ti–46.7Al–1.3Fe–1.1V–0.35B (mol%), has been developed as a casting material for high temperature structural use in aero-engines. This alloy is characterized by the addition of Fe and V which improve castability. The blades for use in a stage 5 low pressure turbine were cast and its engineering applicability was demonstrated by a 500 flight cycles test in a CF6 engine (Nakagawa et al., in: Y.W. Kim, R. Wagner, M. Yamaguchi, Gamma Titanium Aluminides, TMS Annual Meeting, Las Vegas, NV, 1995, pp. 415–424). In the context of wide application, microstructure effects on tensile properties of TiAl–Fe–V–B alloy have been investigated. The optimization of heat treatment conditions and metallurgical features, such as grain structure, grain size as well as aluminum and oxygen content, have been considered to improve the room temperature strength and ductility in this study. As a result, a heat treatment process has been developed to produce TiAl–Fe–V–B alloy, which leads to tensile elongations at room temperature of more than 1.8%.