Observation of {211} < 1 11¯>β deformation twins in laser powder bed fusion manufactured Ti-6Al-4V

• Published in: Materials letters Vol. 370; p. 136771
• Main Authors: Nurly, Hasfi F., Ren, Dechun, Cai, Yusheng, Ji, Haibin, Yang, Rui
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2024
• Subjects: Additive manufacturing; Deformation and fracture; Metals and alloys; Ti-6Al-4V; β phase twinning; Metals and alloys; β phase twinning; Additive manufacturing; Deformation and fracture; Ti-6Al-4V
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2024.136771

[Display omitted] •First time report of {211}<111¯>β deformation twins in PBLFed Ti-6Al-4 V.•Discovery of {211}<111¯>β deformation twins as a stress relieving mechanism for (011¯0)[21¯1¯0]α′ prismatic slip.•Confirmation of {101¯1}α transformation twinning in α′ martensite of PBLFed Ti-6Al-4 V. {211} < 1 11¯>β deformation twins were observed for the first time in a laser powder bed fusion manufactured Ti-6Al-4V alloy containing 0.25 wt.% oxygen, after tensile deformation to failure at room temperature. The relatively high level of oxygen content promotes the {101¯1}α transformation twinning in the α′ martensite, but reduces the size of the α′ martensite laths in the as-built state. {211} < 1 11¯>β twinning was shown to be an effective mechanism to relieve the stress concentration at the α′/β interface created by the (01 1¯ 0)[2 1¯1¯ 0]α′ prismatic slip of the α′ phase, as facilitated by the Burgers orientation relationship between the two phases.