Investigations on the effect of build orientation on the properties of wire electron beam additive manufactured Ti-6Al-4V alloy

Abstract

In the present scenario, wire additive manufacturing is the most effective and efficient technique adopted to realize complex and bulky components in aerospace applications. The current work mainly investigates the heterogeneous and anisotropic behavior of the electron bean wire additive manufactured Ti-6Al-4V. To investigate the effect of build orientation, cuboids were built to extract cylindrical samples with axis parallel to Z-axis, X-axis, Y-axis, and inclined at 45° to the base X-Y plane. Non-destructive inspection using radiography was conducted to ensure the attainment of defect-free samples. Further, the samples were subjected to advanced material characterization techniques. Microstructural features of as-built samples reveal the large columnar prior beta grains attributed to the rapid cooling in the vacuum chamber. Electron backscatter diffraction analysis shows β phase solidified as columnar grains. The martensite structure is observed in the Transmission electron microscopic analysis of the fabricated samples. The tensile samples build at different orientations exhibits the higher yield strength and higher percentage elongation for the sample built along Z-axis. The tensile strength and elongation of the additive built samples are found to be better than that of wrought Ti-6Al-4V. The fractography analysis on the fractured specimen reveals the failure through ductile mode.