Microstructure and corrosion behavior of differently heat-treated Ti-6Al-4V alloy processed by laser powder bed fusion of hydride-dehydride powder

• Published in: Corrosion science Vol. 224; p. 111495
• Main Authors: Delpazir, Melody H., Asherloo, Mohammadreza, Nasiri Khalil Abad, Sajjad, Thompson, Alaina, Guma, Victor, Bagi, Sourabh D., Sreenivas, Keerthi Kumar, Paliwal, Muktesh, Terry, Jeff, Rollett, Anthony D., Mostafaei, Amir
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2023
• Subjects: Additive manufacturing; Heat treatment; Passive film; Titanium; XPS; Titanium; Heat treatment; XPS; Passive film; Additive manufacturing
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2023.111495

This study investigates the use of hydride-dehydride non-spherical Ti-6Al-4V powders in laser powder bed fusion process and the effects of post-heat-treatments on additively manufactured parts. As-built parts show anisotropic microstructure with α′ martensite and some β phases. Post heat-treated parts exhibit α + β phases, with characteristics dependent on the heat treatment. Heat treatment below β-transus leads to homogenized grain structures with improved corrosion resistance. Electrochemical analysis reveals a very stable corrosion rate due to faster formation of a protective passive layer aided by the fine-structured β phase. X-ray photoelectron spectroscopy examines corrosion behavior and film growth mechanism in saline water.
•Laser powder bed fusion of hydride-dehydride Ti-6Al-4V powder.•Microstructure and texture analysis using optical and scanning electron microscopy.•Electrochemical behavior of differently heat-treated parts in saline water.•Oxide layer analysis suing X-ray photon spectroscopy.