|About this Abstract
||Materials Science & Technology 2012
||Recent Advances in Phase Transformations and Structural Evolution in Titanium and its Alloys
||The Pseudo-Spinodal Mechanism of Alpha Nucleation in Titanium Alloys
||Pavani Kami, Amit Behera, Soumya Nag, Yufeng Zheng, Robert E.A. Williams, Jaimie Tiley, Hamish L Fraser, Rajarshi Banerjee
|On-Site Speaker (Planned)
Classical nucleation and growth is the commonly accepted mechanism of second phase precipitation in many metallic alloy systems including titanium alloys. This study presents experimental evidence of a non-classical decomposition mechanism in metallic alloys, involving local compositional fluctuations of small amplitude within the parent phase, leading to homogeneous precipitation of the product phase, with a different crystal symmetry, also referred to as pseudo-spinodal decomposition. An extremely large density of nucleation sites coupled with far-from equilibrium compositions of both parent and product phases, at the formation stage, are characteristic features of this non-classical precipitation mechanism. Experimental observations indicate the possibility of pseudo-spinodal decomposition in case of the intra-granular precipitation of alpha within the beta (bcc) matrix of multiple titanium alloy systems, including both simple binary systems such as Ti-Mo and Ti-V as well as more complex, commercially relevant systems such as, Ti-5553 and Beta-21S.
||Planned: Metallurgical and Materials Transactions