Study of Mechanisms for Fine Scale Alpha Phase in Beta Titanium Alloys

The present work focuses on a study of different mechanisms to engineer homogeneously distributed fine sized alpha precipitates in the beta matrix of beta titanium alloys. The precipitation of metastable phases (such as omega phase) upon low temperature aging and their influence on alpha precipitation is studied in detail. The precipitation sequence on direct aging above the omega solvus temperature is also assessed. The structural and compositional evolution of precipitate phase is determined using multiple characterization tools (3DAP, TEM, SEM, Synchrotron XRD). The possibility of occurrence of other non-classical precipitation mechanisms that do not require heterogeneous nucleation sites are also analyzed. Lastly, the influence of interstitial element, oxygen on alpha precipitation during the oxidation of Beta 21S has been determined. The ingress of oxygen and its influence on microstructure have also been correlated to measured mechanical properties.