Designing a thermodynamically stable and intrinsically ductile refractory alloy

Murty, B S (2023) Designing a thermodynamically stable and intrinsically ductile refractory alloy. Journal of Alloys and Compounds, 939. p. 168597. ISSN 0925-8388

Text
1-s2.0-S092583882204988X-main.pdf - Published Version
Download (2MB)

Abstract

Developing ductile refractory alloys have remained a challenge. Decreasing the valence electron concentration of refractory alloys has been widely suggested for improving their ductility. However, Re has been used to ductilize W, which goes against the low valency suggestion. The thermodynamic stability of refractory alloys has never been considered while suggesting alloying elements to improve ductility. Here we use first-principles density functional theory simulations to unravel the role of enthalpy of formation in improving the intrinsic ductility of refractory alloys. The intrinsic ductility is assessed using the D-parameter, which is the ratio of surface energy and unstable stacking fault energy. We studied 25 equiatomic binary refractory alloys and found that positive enthalpy of formation improves ductility. The small positive enthalpy of formation could be compensated by sufficiently large entropy; hence the alloy is expected to be a single phase. Our present work explains the role of high-valency and low-valency alloying elements in improving the ductility of refractory alloys. These findings provide a path to design thermodynamically stable and intrinsically ductile high-temperature alloys.

[error in script]

IITH Creators:

IITH Creators	ORCiD
Murty, B S	https://orcid.org/0000-0002-4399-8531

Item Type:

Article

Uncontrolled Keywords:

Composition fluctuations; Enthalpy; High-temperature alloys; Metals and alloys; Surfaces and interfaces; Transition metal alloys and compounds; Alloying; Alloying elements; Binary alloys; Density functional theory; Ductility; Refractory metals; Thermodynamic stability; Composition fluctuations; Density functional theory simulations; Enthalpies of formation; First-principle density-functional theories; Metals and alloys; Surfaces and interfaces; Thermodynamically stable; Transition metal alloys and compounds; Valence electron concentration; Valencies; Enthalpy

Subjects:

Materials Engineering > Materials engineering
Materials Engineering > Composite materials

Divisions:

Department of Material Science Engineering

Depositing User:

Mr Nigam Prasad Bisoyi

Date Deposited:

11 Sep 2023 04:10

Last Modified:

11 Sep 2023 04:10

URI:

http://raiithold.iith.ac.in/id/eprint/11663