Corrosion and mechanical properties of Ti­–5Mo–2Fe alloy fabricated by powder and ingot metallurgy process

Abstract

Improving the manufacturability of titanium alloys and facilitating the production of complex parts through advanced powder metallurgy (PM) processes is of great importance. In this study, a Ti–5Mo–2Fe alloy was fabricated via both ingot metallurgy (IM) and PM processes. The mechanical and corrosion properties were evaluated using hardness measurements, room-temperature tensile tests, potentiodynamic polarisation experiments, potentiostatic polarisation experiments, and immersion tests. The IM alloy exhibited a basket weave structure and the PM alloy exhibited a layered α+β Widmanstätten structure with α/β lamellar colonies. Both the IM and PM alloys exhibited excellent mechanical properties, but owing to its porosity, the PM alloy fractured before the yield point. The PM alloy exhibited superior corrosion resistance with a higher E_corr and lower I_corr, possibly owing to the thicker passivation film with higher oxygen content generated by the PM alloy, which enhances the corrosion properties by providing superior structural stability.