Effects of the crystallographic and spatial orientation of a lamellae on the anisotropic in-situ tensile behaviors of additive manufactured Ti-6Al-4V

Columnar grain morphology and typical alpha texture transformed from a strong beta<100>//VD fiber texture are found in the Ti-6Al-4V alloy fabricated using electron beam rapid manufacturing (EBRM). This study mainly focused on the effect of the columnar grain morphology and the lamellar alpha orientation on the tensile damage behavior of the alloy. Samples in three different orientations were subjected to in-situ tensile tests. Results demonstrated that obvious anisotropic in-situ tensile behavior was presented in the alloy. Based on the columnar grain morphology and the beta<100>//VD fiber texture, we analyzed the crystallographic and spatial orientation characteristics of alpha lamellae in the alloy, discussed the effect of the columnar grain morphology, the crystallographic and spatial orientations of alpha lamellae on anisotropic in-situ tensile behaviors, and proposed that the crystallographic texture of alpha phase was a main factor inducing anisotropic tensile properties. In addition, the anisotropic fracture displacement was also associated with the spatial orientation of alpha laths. (C) 2020 Elsevier B.V. All rights reserved.