First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications

NbRu has a potential as a high-temperature shape-memory alloy (HTSMA) because it has a martensitic transformation temperature above 1000 °C. However, its shape-memory properties could be improved for consideration in the aerospace and automotive industry. The unsatisfactory shape-memory properties c...

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Main Authors: Duduzile Nkomo, Yu-Nien Shen, Roelf Mostert, Yoko Yamabe-Mitarai, Maje Phasha
Format: Article
Language:English
Published: MDPI AG 2024-08-01
Series:Metals
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Online Access:https://www.mdpi.com/2075-4701/14/9/976
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author Duduzile Nkomo
Yu-Nien Shen
Roelf Mostert
Yoko Yamabe-Mitarai
Maje Phasha
author_facet Duduzile Nkomo
Yu-Nien Shen
Roelf Mostert
Yoko Yamabe-Mitarai
Maje Phasha
author_sort Duduzile Nkomo
collection DOAJ
description NbRu has a potential as a high-temperature shape-memory alloy (HTSMA) because it has a martensitic transformation temperature above 1000 °C. However, its shape-memory properties could be improved for consideration in the aerospace and automotive industry. The unsatisfactory shape-memory properties could be associated with the presence of a brittle tetragonal L1<sub>0</sub> martensitic phase. Therefore, in an attempt to modify the transformation path from B2→L1<sub>0</sub> in preference of either B2→orthorhombic or B2→monoclinic (MCL), an addition of B2 phase stabiliser, titanium (Ti), has been considered in this study to partially substitute niobium (Nb) atoms. The ab initio calculations have been conducted to investigate the effect of Ti addition on the thermodynamic, elastic, and electronic properties of the Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> in B2 and L1<sub>0</sub> phases. The results showed that the B2 and L1<sub>0</sub> phases had comparable stability with increasing Ti content. The simulated data presented here was sufficient for the selection of suitable compositions that would allow the L1<sub>0</sub> phase to be engineered out. The said composition was identified within 15–30 at.% Ti. These compositions have a potential to be considered when designing alloys for structural application at high temperatures above 200 °C.
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spelling doaj-art-cd0c72b44ce74183a17b7b4041278d8b2025-08-20T01:55:41ZengMDPI AGMetals2075-47012024-08-0114997610.3390/met14090976First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural ApplicationsDuduzile Nkomo0Yu-Nien Shen1Roelf Mostert2Yoko Yamabe-Mitarai3Maje Phasha4Advanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg 2125, South AfricaDepartment of Advanced Materials Science, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8561, JapanDepartment of Materials Science and Metallurgical Engineering, University of Pretoria, Hatfield, Pretoria 0028, South AfricaDepartment of Advanced Materials Science, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8561, JapanAdvanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg 2125, South AfricaNbRu has a potential as a high-temperature shape-memory alloy (HTSMA) because it has a martensitic transformation temperature above 1000 °C. However, its shape-memory properties could be improved for consideration in the aerospace and automotive industry. The unsatisfactory shape-memory properties could be associated with the presence of a brittle tetragonal L1<sub>0</sub> martensitic phase. Therefore, in an attempt to modify the transformation path from B2→L1<sub>0</sub> in preference of either B2→orthorhombic or B2→monoclinic (MCL), an addition of B2 phase stabiliser, titanium (Ti), has been considered in this study to partially substitute niobium (Nb) atoms. The ab initio calculations have been conducted to investigate the effect of Ti addition on the thermodynamic, elastic, and electronic properties of the Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> in B2 and L1<sub>0</sub> phases. The results showed that the B2 and L1<sub>0</sub> phases had comparable stability with increasing Ti content. The simulated data presented here was sufficient for the selection of suitable compositions that would allow the L1<sub>0</sub> phase to be engineered out. The said composition was identified within 15–30 at.% Ti. These compositions have a potential to be considered when designing alloys for structural application at high temperatures above 200 °C.https://www.mdpi.com/2075-4701/14/9/976shape-memory alloyalloy designelastic propertieselectronic structuremartensitic transformationab initio calculations
spellingShingle Duduzile Nkomo
Yu-Nien Shen
Roelf Mostert
Yoko Yamabe-Mitarai
Maje Phasha
First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications
Metals
shape-memory alloy
alloy design
elastic properties
electronic structure
martensitic transformation
ab initio calculations
title First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications
title_full First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications
title_fullStr First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications
title_full_unstemmed First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications
title_short First-Principle Study on Tailoring the Martensitic Transformation of B2 Nb<sub>50−x</sub>Ti<sub>x</sub>Ru<sub>50</sub> Shape-Memory Alloy for Structural Applications
title_sort first principle study on tailoring the martensitic transformation of b2 nb sub 50 x sub ti sub x sub ru sub 50 sub shape memory alloy for structural applications
topic shape-memory alloy
alloy design
elastic properties
electronic structure
martensitic transformation
ab initio calculations
url https://www.mdpi.com/2075-4701/14/9/976
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