Characterization of the effect of vanadium additions to TiAl base alloys

Abstract

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 γ + α 2 alloys, altough not single-phase alloys. The suctibility increase which is attributable to the V addition is small (∼0.5%), compared with that attributable to the duplex structure effect (∼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 α 2/ γ volume ratio in transformed regions.