Intermetallic alloys based on gamma titanium aluminide

Abstract

Titanium-aluminide alloys based on TiAl have an excellent potential to become one of the most important aerospace materials because of their low density, high melting temperature, good elevated-temperature strength and modulus retention, high resistance to oxidation and hydrogen absorption, and excellent creep properties. The chief roadblock to their application is poor ductility at low to intermediate temperatures that results in low fracture toughness and a fast fatigue-crack growth rate. During the last several years, a great deal of effort has been made to improve these ductile properties. These endeavors have met with some success through chemistry modification and microstructure control. © 1989 TMS.