Preparation of Ti-5553 Alloy by Different Extrusion Processes from Elemental Powder Mixtures

Abstract

Ti-5553 (Ti-5Al-5V-5Mo-3Cr, wt. %) alloy is a recently developed near β titanium alloy and it has a very good hardenability, good ductility and high strength. In this study, we discussed the feasibility of preparing Ti-5553 alloy by different processes from powder mixtures of hydride-dehydride titanium powder, elemental powders and master alloy powders, including (1) direct extrusion of powder compact in argon, (2) extrusion of the vacuum-sintered billet in air and (3) extrusion of the hot-pressed billet in air. XRD, OM and SEM were used to determine the phase constitutions and microstructures of the prepared Ti-5553 alloys, and mechanical test was performed to examine their mechanical properties. The results showed the microstructures and phase constitutions of Ti-5553 alloys were significantly affected by different processes, which resulted in the relevant mechanical properties. The effect of the selected heat treatment on the microstructures and properties of Ti-5553 alloy were investigated as well.