Two-dimensional sections of the yield locus of a Ti6%Al4%V alloy with a strong transverse-type crystallographic α-texture

Abstract

Results obtained from mechanical tests on a Ti6%Al4%V sheet alloy were used to obtain the biaxial normal stress and the in-plane simple shear flow stress sections of its yield locus. The critical resolved shear stress (CRSS) of the different activated slip systems is derived from these experimental results of mechanical tests combined with microstructural observations. A strong asymmetry of the CRSS and some influence on it of the hydrostatic stress state was found for pyramidal 〈 c + a〉 systems, i.e. a deviation from the Schmid law. Owing to the high sharpness of the texture in this alloy, a quasi-single-crystal approximation of the plastic anisotropy on the rolling plane (RP) and of the yield locus sections measured was made. The good agreement between the simulated and the experimental results encourages the use of the proposed CRSS values for a simulation of polycrystalline texture development and yield locus derivation.