Author : Yunting Su
Release : 2023-07-06
Genre : Technology & Engineering
Kind : eBook
Book Rating : /5 ( reviews)

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Book Synopsis Composition- and temperature-dependence of β to ω phase transformation in Ti-Nb alloys by : Yunting Su

Download or read book Composition- and temperature-dependence of β to ω phase transformation in Ti-Nb alloys written by Yunting Su. This book was released on 2023-07-06. Available in PDF, EPUB and Kindle. Book excerpt: ω phases have shown great effects on the superelasticity and modulus of metastable β-Ti alloys. In this study, the microstructure evolution during cooling and aging for β → ω phase transformation is investigated by integrating a thermodynamic database with phase field simulations. Our CALPHAD calculations based on an available thermodynamic database give the Gibbs energies of metastable β (Nb-lean β1 + Nb-rich β2 produced via spinodal decomposition) and ω phases in Ti-Nb. Informed by the results, our phase field simulations show that the formation mechanisms of ω exhibit dependence on the composition and temperature. The ω can form in Ti-26 at.% Nb without the assistance of spinodal decomposition. Further analysis shows that the precursory spinodal decomposition in the β phase occurs in Ti-50 at.% Nb, and could induce geometrically confined ω. The novel transformation pathway could create unique morphology of ω. This study could elucidate new insights into the ω phase transformation in Ti-Nb alloys and metastable β-Ti alloys having spinodal decomposition.