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Properties of β/ω phase interfaces in Ti and their implications on mechanical properties and ω morphology.

Authors :
Cao, Shuo
Jiang, Yong
Yang, Rui
Hu, Qing-Miao
Source :
Computational Materials Science. Feb2019, Vol. 158, p49-57. 9p.
Publication Year :
2019

Abstract

Graphical abstract Highlights • The interface energies and GSFE of β / ω interface in Ti alloy are calculated. • The strong anisotropy of the interface energy contributes to the ellipsoid-like morphology of β particles, with its major axis parallel to 〈1 1 1〉 β direction. • The β / ω interface is prone to crack initiation and propagation as compared to the bulk and contributes to the ω -embrittlement of β -Ti alloys. Abstract ω phase precipitating in a β -Ti alloy is generally detrimental to the ductility and plasticity of the alloy.To understand the influence of ω phase on the mechanical properties of β -Ti alloys, the property of the β / ω interface is demanded.In this regard, we calculate the interface energies ( γ int ), cleavage energies ( γ cl ), and generalized stacking fault energies (γ) of the β / ω interfaces with different orientations using a first-principles method.Our calculations predict interface energies of 0.32 J m−2 and 0.03 J m−2 for the (1 1 1 ¯) β / (0 0 0 1) ω and (1 1 2) β / (1 0 1 ¯ 0) ω interfaces, respectively.The strong anisotropy of the interface energy contributes to the ellipsoid-like morphology of ω phase with its major axis parallel to the 〈 1 1 1 〉 β direction.The influence of the interface on the ductility of the alloy is discussed with the calculated cleavage energies and the unstable stacking fault energies (γ us) extracted from the generalized stacking fault energy (GSFE). The γ cl / γ us ratio of the (1 1 2) β / (1 0 1 ¯ 0) ω interface is lower than those of the main slip planes of the bulk phases, indicating that this interface is prone to crack initiation and propagation as compared to the bulk and contributes to the ω -embrittlement of β -Ti alloys. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
09270256
Volume :
158
Database :
Academic Search Index
Journal :
Computational Materials Science
Publication Type :
Academic Journal
Accession number :
134184350
Full Text :
https://doi.org/10.1016/j.commatsci.2018.10.042