A simple and efficient method for creating the beta phase through the selective laser melting process of Ti-10Mo powder mixed alloy; A corrosion approach

Document Type : Article frome a thesis

Authors

• Arezoo Pourshoja ¹
• karim Avak ¹
• Maziyar Azadbeh ²
• Mohammadreza Etminanfar ¹
• Mehdi Ojaghi ¹

¹ Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran

² Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran.

10.30495/jnm.2024.33378.2040

Abstract

Abstract
Introduction: Titanium alloys containing the β phase have much better corrosion resistance. Some alloying elements, such as Mo, stabilize this phase. Among the Ti alloys that contain this element, the Ti-10Mo alloy is of particular importance. If this alloy is produced using selective laser melting (SLM), it will be an approach that is user-friendly due to the nature of the process.
Methods: Samples were printed by SLM process. The constituent phases were determined by XRD. The microstructure was evaluated using optical and scanning electron microscopes. Corrosion behavior was evaluated by cyclic potentiodynamic polarization and electrochemical impedance spectroscopy.
Findings: In the XRD pattern of pure Ti powder and printed sample, α and α/α' phases are seen, respectively. However, Ti-10Mo powder mixture consists of α and Mo phases, the β phase is more dominant in printed sample because of the Mo penetration in the Ti matrix. As well as, in the microstructure of Ti10Mo the beta phase is seen as Mo-rich streaks, whereas in pure Ti it is found relatively negligible as epitaxially grown primary columnar β grains with acicular α' martensite phase. Mo addition to pure Ti reduces its passive current density and stabilize oxide film. However, Ti-10Mo alloy, with its various phases and galvanic couples, experiences rupture of the passive oxide film at higher potentials, leading to pitting corrosion. The impedance module value of Ti-10Mo is higher than that of pure Ti. Both samples have a double passive oxide film, with Ti-10Mo alloy exhibiting higher resistance than pure Ti.

Keywords

• Ti-10Mo
• Pure Ti
• Selective laser melting
• Corrosion
• beta phase

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