Densification Process and Properties of Powder Metallurgy Ti-5Al-2.5Sn Alloy

Net shape process from pre-alloyed powder has become a viable approach to manufacture high-performance, complex shaped titanium alloy components. In this work densification of Ti-5Al-2.5Sn powder compacts in mild steel containers by means of hot isostatic pressing was studied. Due to the shielding effect of the container, inhomogeneous deformation of Ti-5Al-2.5Sn powder compacts was observed during the experiment and this was also predicted by a finite element analysis. The mechanical properties of powder metallurgy (PM) Ti-5Al-2.5Sn alloy of different density were compared. Near-net-shape forming processes of PM titanium alloy parts are studied. By using metal capsules and metal internal tooling, near-net-shaping of PM parts with complex shapes was demonstrated. The design of capsules and tooling was found very important because of the different shrinkage ratio of the differently shaped regions of the component.