CHARACTERIZATION OF THE EFFECT OF VANADIUM ADDITIONS TO TIAL BASE ALLOYS

Ternary TiAl-base alloys containing V have been studied, using rapid-solidification processed materials. The mechanical behavior has been characterized and related to other results on microstructure, lattice parameters, site occupancy, phase stability, and deformation mode. It was found that V additions enhance the plasticity of duplex gamma + alpha-2 alloys, although not single-phase alloys. The ductility increase which is attributable to the V addition is small (approximately O.5%), compared with that attributable to the duplex structure effect (approximately 1%) as previously determined in a binary alloy study. The ductilization effect of V is partially due to its ability to occupy Al lattice sites and modify the Ti-Al bond. It is also partially due to its ability to promote twin formation, by modifying the Al partitioning and therefore the alpha-2/gamma-volume ratio in transformed regions.