Ordered intermetallic alloys, part III: Gamma titanium aluminides

TL;DR: In this paper, an improved understanding of both fundamental and practical aspects of these aluminides, such as phase relations, microstructure evolution and control, processing, micro-structure-property relationships, and deformation and fracture processes, is presented.

Abstract: Extensive research during the last eight years has resulted in the development and improvement of second-generation gamma alloys of engineering importance, Ti-48Al-2(Cr or Mn)-2Nb and derivatives. These alloys exhibit properties, in duplex micro-structural forms, meeting requirements for some gas-turbine and automobile engine components that may be used up to 760 °C. These achievements were made possible by an improved understanding of both fundamental and practical aspects of these aluminides, such as phase relations, microstructure evolution and control, processing, microstructure-property relationships, and deformation and fracture processes. Nevertheless, widespread higher performance and/or higher-temperature applications of these alloys appear unlikely unless the current properties are dramatically improved.