Studying the effects of Nb on high-temperature deformation in TiAl alloys using atomistic simulations

Intermetallic γ(TiAl)-based alloys find their application as high-temperature materials for aero engine and automotive components. Microstructure optimization and microalloying play key roles in optimizing these alloys. Several pioneering experimental works showed improved mechanical properties of γ(TiAl)-based alloys containing Niobium (Nb). Despite Nb being a key alloying element, its contribution remains debated, if not least understood, due to the TiAl microstructure's complexity with hierarchical interfaces. This work examines the effects of Nb on the high-temperature deformation behavior of TiAl alloys using atomistic simulations. These revealed that Nb alloying retarded the stress-induced phase transformation of γ → α2, favoring a refined microstructure with the dislocation sources from microstructure boundaries and interfaces at high temperature and improving thus the ductility. Our microstructure-informed atomistic models reveal a comprehensive picture of the underlying nanomechanical events.

Subjects

Density functional theory

Ductility

Molecular dynamics

Nanomechanics

Strength

TiAlNb alloy

DDC Class

620: Engineering

Publication version

publishedVersion

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

1-s2.0-S0264127523010122-main.pdf

Type

Main Article

Size

10.1 MB

Format

Adobe PDF

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Studying the effects of Nb on high-temperature deformation in TiAl alloys using atomistic simulations