Fracture Mechanics Characterization of Intermetallic T_iAl Compounds at High Temperatures

Abstract

Intermetallic compounds are attractive candidate as high performance materials for an elevated temperature environment in a field of aeronautic and aerospace technologies. However, general exploitation of these materials has been limited by the lack of significant ductility and fracture toughness. The final goal of this research is to establish the material design concepts of intermetallic compounds for both high strength and toughness. In this paper, flexural and fracture toughness tests were conducted on titanium aluminides TiAl, which are fabricated by both the self-propagating high temperature synthesis(SHS) procedure and the casting method, at high temperature ranges (~1000°C). Temperature dependences of flexural strength and fracture toughness were investigated on the basis of linear-elastic fracture mechanics and electron-microfractography.