First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

Abstract For decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experimen...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	R. Salloom, S. A. Mantri, R. Banerjee, S. G. Srinivasan
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/665d0be8afd14341a583d72997a039f0
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:665d0be8afd14341a583d72997a039f0
record_format	dspace
spelling	oai:doaj.org-article:665d0be8afd14341a583d72997a039f02021-12-02T15:03:07ZFirst principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior10.1038/s41598-021-91594-52045-2322https://doaj.org/article/665d0be8afd14341a583d72997a039f02021-06-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-91594-5https://doaj.org/toc/2045-2322Abstract For decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.R. SalloomS. A. MantriR. BanerjeeS. G. SrinivasanNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-21 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q R. Salloom S. A. Mantri R. Banerjee S. G. Srinivasan First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
description	Abstract For decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.
format	article
author	R. Salloom S. A. Mantri R. Banerjee S. G. Srinivasan
author_facet	R. Salloom S. A. Mantri R. Banerjee S. G. Srinivasan
author_sort	R. Salloom
title	First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
title_short	First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
title_full	First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
title_fullStr	First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
title_full_unstemmed	First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
title_sort	first principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/665d0be8afd14341a583d72997a039f0
work_keys_str_mv	AT rsalloom firstprinciplescomputationofcompositiondependentelasticconstantsofomegaintitaniumalloysimplicationsonmechanicalbehavior AT samantri firstprinciplescomputationofcompositiondependentelasticconstantsofomegaintitaniumalloysimplicationsonmechanicalbehavior AT rbanerjee firstprinciplescomputationofcompositiondependentelasticconstantsofomegaintitaniumalloysimplicationsonmechanicalbehavior AT sgsrinivasan firstprinciplescomputationofcompositiondependentelasticconstantsofomegaintitaniumalloysimplicationsonmechanicalbehavior
_version_	1718389082302709760

First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

Ejemplares similares