High strength and ductility of electron beam melted 13 stabilized gamma-TiAl alloy at 800 degrees C

Abstract

A nearly fully dense beta stabilized gamma-TiAl alloy was additively manufactured by electron beam melting. The as-fabricated specimen exhibited a fine structure consisting of alpha(2)/gamma colonies (< 5 mu m), equiaxed gamma (1 mu m) and beta(o) (< 1 mu m) grains. The unique microstructure rendered high strength (580 MPa) and high ductility (> 50%) in the sample at 800 degrees C. Annealing and subsequent stabilization treatments resulted in alpha(2)/gamma colonies (< 50 mu m) with an ultrafine (20-40 rim) lamellar structure, which gave rise to high strength (770 MPa) and good ductility (6%) levels superior to those of conventional counterparts and other gamma-TiAl alloys at 800 degrees C.