Composition, microstructure and corrosion resistance of DED-LB additively manufactured Ti–6Al–4V alloy : comparison with wrought alloy

Milošev, Ingrid (author), Rodič, Peter (author), Kapun, Barbara (author), Sačer, Denis (author), Nair, Anish (author), Kramar, Davorin (author), Jeromen, Andrej (author), Govekar, Edvard (author)

The titanium alloy Ti–6Al–4 V is widely used in medical applications due to its favourable mechanical properties, biocompatibility, and excellent corrosion resistance. This study aims to study the composition, structure and electrochemical behaviour of additively manufactured Ti–6Al–4 V alloy produced by a directed-energy deposition of powder using a laser beam (DED-LB) and compare it to wrought alloy produced by conventional metallurgy. The surface morphology and composition of the chemo-mechanically polished wrought and DED-LB samples were analysed by X-ray diffraction, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy coupled with scanning Kelvin probe force microscopy and X-ray photoelectron spectroscopy. The electrochemical behaviour was assessed using potentiodynamic polarisation and electrochemical impedance spectroscopy in three simulated physiological solutions (Hanks’ balanced salt solution, NaCl, and artificial saliva) at 37 °C. Both alloys show highly protective corrosion behaviour in the tested media, confirming that DED-LB Ti–6Al–4 V is a promising alternative to conventional manufacturing methods for advanced metallurgical engineering applications. The alloys exhibit similar general chemical composition but different microstructure, with a lamellar αʼ-martensitic phase in the DED-LB fabricated alloy surrounded by prior β grains contrasting equiaxed α+ β structure of the wrought alloy. Differences in microstructure are related to differences in local chemical composition, which affect the course of the corrosion when polarised to high positive potentials of 6 V$_{Ag/AgCl}$.

• Language: English
• Keywords: titanium alloys, directed-energy deposition by laser beam, simulated physiological solution, Ti–6Al–4V alloy, additive manufacturing, microstructure, corrosion
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 19 str.
• Numbering: Vol. 1033, art. 181280
• PID: 20.500.12556/RUL-169564
• UDC: 620.1/.2
• ISSN on article: 1873-4669
• DOI: 10.1016/j.jallcom.2025.181280
• COBISS.SI-ID: 238139907
• Publication date in RUL: 04.06.2025

Record is a part of a journal

• Title: Journal of alloys and compounds
• Publisher: Elsevier
• ISSN: 1873-4669
• COBISS.SI-ID: 23089925

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: titanove zlitine, kovane zlitine, aditivna proizvodnja, mikrostruktura, korozija