CYCLIC FATIGUE AND FRACTURE-BEHAVIOR OF A GAMMA-TITANIUM ALUMINIDE INTERMETALLIC

In this paper, the cyclic fatigue and fracture behavior of a gamma-tit anium aluminide intermetallic is examined. Specimens of the intermetal lic were cyclically deformed under fully-reversed, total strain-amplit ude control loading at two different strain amplitudes. The observed s tress response characteristics, cyclic strain resistance and resultant low-cycle fatigue life are presented. The cyclic fracture was found t o be a mixture of cleavage-type and intergranular rupture. The cyclic stress-strain response, deformation and fracture characteristics of th e ordered intermetallic are discussed in light of competing and synerg istic influences of intrinsic microstructural effects, cyclic strain a mplitude, response stress and ductility of the material.