Open AccessSolidification sequence and phase equilibria in Ti-47Al-22Nb and Ti-47Al-20Nb ternary alloys
Author(s) -
Xiangjun Xu,
Shuai Xu,
Simbarashe Fashu
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abaea3
Subject(s) - phase (matter) , materials science , ternary operation , thermodynamics , quenching (fluorescence) , microstructure , phase diagram , metallurgy , titanium alloy , transformation (genetics) , alloy , chemistry , physics , biochemistry , organic chemistry , computer science , programming language , quantum mechanics , fluorescence , gene
The phase transformation sequences and phase equilibria in Ti-47Al-20Nb and Ti-47Al-22Nb (at.%) alloys were investigated through experiments and computational (CALculation of PHAse Diagrams) techniques. Experiments to study nonequilibria phase transformations involved quenching the alloys from high temperature followed by composition and microstructure characterization. The computed results show that with increase in temperature, the α + β + γ tie-triangle phase region shifts towards low Nb content. On the contrary, experimental results show that with increase in temperature the tie-triangle of α + β + γ moves towards high Nb content. These changes are attributed to the expansion of the α phase region and corresponding changes of the primary α , β and γ phase regions with increase in temperature. In the experimentally studied alloys, a part of the α phase transformed to γ phase by massive transformation and most of the β phase transformed to γ phase in high Nb content alloys.