Deformation behaviors of as-built and hot isostatically pressed Ti-6Al-4V alloys fabricated via electron beam rapid manufacturing

The deformation behavior of as-built and hot isostatically pressed (HIP) Ti-6Al-4 V alloys fabricated using electron beam rapid manufacturing (EBRM) were investigated in this work. The deformation characteristics were characterized using a laser scanning confocal microscope and electron back-scattered diffraction (EBSD). In the as-built sample, prismatic slip was the main mode of deformation, as well as a small amount of basal slip and cross-slip. Some planar slip lines with large length scales were observed across several c lamellae. After hot isostatical pressing, prismatic and basal slip were the main mode of deformation, accompanied by abundant cross-slip and multiple slip, and most of the slip lines were blocked within an c lamellae. These differences in deformation behavior were associated with the coarsening of c laths and the more retained p phase after HIP compared to the as-built alloy. More cross-slip and multiple slip can lead to superior elongation-to-failure and a greater strain hardening effect in the HIP alloy compared to the as-built sample. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.