Examination of the twinning activity in additively manufactured Ti-6Al-4V

This present paper investigates the dominant twinning mode and secondary twin via transmission electron microscopy at different positions of additively manufactured (AM) Ti-6Al-4V deposition wall fabricated by laser metal deposition (LMD). {10-11} <-1012 > twinning system is observed as the dominant twinning mode. Secondary twins, including the inserting secondary twin and neighboring secondary twin, are characterized at position with sufficient thermal cycle history. These twinning morphologies can be rationalized to some degree from the standpoint of the twinning effect and thermal condition in additive manufacturing. This work gets insight into the twinning evolution in additively manufactured Ti alloys. (C) 2018 Elsevier Ltd. All rights reserved.