Influence of cooling rate on the precipitation kinetics of nanoscale isothermal ω-phase in metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr

Deepak Sharma; David Parfitt; Bo Chen; Bryan Roebuck; Diego Alba Venero; Sitarama Raju Kada; Daniel Fabijanic; Michael E. Fitzpatrick

doi:10.1016/j.jallcom.2020.157822

Influence of cooling rate on the precipitation kinetics of nanoscale isothermal ω-phase in metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr

Deepak Sharma, David Parfitt, Bo Chen, Bryan Roebuck, Diego Alba Venero, Sitarama Raju Kada, Daniel Fabijanic, Michael E. Fitzpatrick

College of Engineering, Environment & Science

Research output: Contribution to journal › Article › peer-review

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Abstract

In metastable β-Ti alloys, nanoscale isothermal ω-phase (ω _iso) precipitates are regarded as the nucleation sites for the α strengthening phase. Here we investigate the precipitation kinetics of the ω _iso precipitates as a function of cooling rate (air cooling and water quenching) after β-solutionising. A combined in situ small-angle neutron scattering (SANS) and electrical resistivity measurement approach was used during ageing of Ti–5Al–5Mo–5V–3Cr wt% (Ti-5553) alloy at 300 °C and 325 °C up to 8 h. The SANS modelling was consistent with ellipsoid shaped particles for the ω _iso precipitates, for both air-cooled and water-quenched samples. The precipitates attained a maximum size (equatorial diameter) of ∼21 nm and ∼17 nm after 2 h and 4 h of ageing the water-quenched and air-cooled samples respectively. Although the air-cooled samples showed delayed nucleation in comparison to water-quenched sample, the volume fraction became approximately the same (∼11%) after ageing for 8 h. The average value of the activation energy for ω _iso nucleation from the β-phase matrix was determined as 122 kJ mol ⁻¹ from electrical resistivity data using a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. The hardness increased with ageing time, with water quenching leading to a higher final value of hardness than air cooling.

Original language	English
Article number	157822
Number of pages	10
Journal	Journal of Alloys and Compounds
Volume	859
Early online date	6 Nov 2020
DOIs	https://doi.org/10.1016/j.jallcom.2020.157822
Publication status	Published - 5 Apr 2021

Bibliographical note

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Alloys and Compounds. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Alloys and Compounds, 859, (2021) DOI: 10.1016/j.jallcom.2020.157822

© 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Funder

Lloyd’s Register Foundation ( LRF ), UK’s Engineering and Physical Sciences Research Council , EPSRC Early Career Fellowship Scheme, EP/R043973/1.

Keywords

Electrical resistivity measurements
Kinetics
Small-angle neutron scattering
Titanium alloys

ASJC Scopus subject areas

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.jallcom.2020.157822

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title = "Influence of cooling rate on the precipitation kinetics of nanoscale isothermal ω-phase in metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr",

abstract = "In metastable β-Ti alloys, nanoscale isothermal ω-phase (ω iso) precipitates are regarded as the nucleation sites for the α strengthening phase. Here we investigate the precipitation kinetics of the ω iso precipitates as a function of cooling rate (air cooling and water quenching) after β-solutionising. A combined in situ small-angle neutron scattering (SANS) and electrical resistivity measurement approach was used during ageing of Ti–5Al–5Mo–5V–3Cr wt% (Ti-5553) alloy at 300 °C and 325 °C up to 8 h. The SANS modelling was consistent with ellipsoid shaped particles for the ω iso precipitates, for both air-cooled and water-quenched samples. The precipitates attained a maximum size (equatorial diameter) of ∼21 nm and ∼17 nm after 2 h and 4 h of ageing the water-quenched and air-cooled samples respectively. Although the air-cooled samples showed delayed nucleation in comparison to water-quenched sample, the volume fraction became approximately the same (∼11%) after ageing for 8 h. The average value of the activation energy for ω iso nucleation from the β-phase matrix was determined as 122 kJ mol −1 from electrical resistivity data using a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. The hardness increased with ageing time, with water quenching leading to a higher final value of hardness than air cooling. ",

keywords = "Electrical resistivity measurements, Kinetics, Small-angle neutron scattering, Titanium alloys",

author = "Deepak Sharma and David Parfitt and Bo Chen and Bryan Roebuck and Venero, {Diego Alba} and Kada, {Sitarama Raju} and Daniel Fabijanic and Fitzpatrick, {Michael E.}",

note = "NOTICE: this is the author{\textquoteright}s version of a work that was accepted for publication in Journal of Alloys and Compounds. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Alloys and Compounds, 859, (2021) DOI: 10.1016/j.jallcom.2020.157822 {\textcopyright} 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ ",

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T1 - Influence of cooling rate on the precipitation kinetics of nanoscale isothermal ω-phase in metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr

AU - Sharma, Deepak

AU - Parfitt, David

AU - Chen, Bo

AU - Roebuck, Bryan

AU - Venero, Diego Alba

AU - Kada, Sitarama Raju

AU - Fabijanic, Daniel

AU - Fitzpatrick, Michael E.

N1 - NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Alloys and Compounds. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Alloys and Compounds, 859, (2021) DOI: 10.1016/j.jallcom.2020.157822 © 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

PY - 2021/4/5

Y1 - 2021/4/5

N2 - In metastable β-Ti alloys, nanoscale isothermal ω-phase (ω iso) precipitates are regarded as the nucleation sites for the α strengthening phase. Here we investigate the precipitation kinetics of the ω iso precipitates as a function of cooling rate (air cooling and water quenching) after β-solutionising. A combined in situ small-angle neutron scattering (SANS) and electrical resistivity measurement approach was used during ageing of Ti–5Al–5Mo–5V–3Cr wt% (Ti-5553) alloy at 300 °C and 325 °C up to 8 h. The SANS modelling was consistent with ellipsoid shaped particles for the ω iso precipitates, for both air-cooled and water-quenched samples. The precipitates attained a maximum size (equatorial diameter) of ∼21 nm and ∼17 nm after 2 h and 4 h of ageing the water-quenched and air-cooled samples respectively. Although the air-cooled samples showed delayed nucleation in comparison to water-quenched sample, the volume fraction became approximately the same (∼11%) after ageing for 8 h. The average value of the activation energy for ω iso nucleation from the β-phase matrix was determined as 122 kJ mol −1 from electrical resistivity data using a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. The hardness increased with ageing time, with water quenching leading to a higher final value of hardness than air cooling.

AB - In metastable β-Ti alloys, nanoscale isothermal ω-phase (ω iso) precipitates are regarded as the nucleation sites for the α strengthening phase. Here we investigate the precipitation kinetics of the ω iso precipitates as a function of cooling rate (air cooling and water quenching) after β-solutionising. A combined in situ small-angle neutron scattering (SANS) and electrical resistivity measurement approach was used during ageing of Ti–5Al–5Mo–5V–3Cr wt% (Ti-5553) alloy at 300 °C and 325 °C up to 8 h. The SANS modelling was consistent with ellipsoid shaped particles for the ω iso precipitates, for both air-cooled and water-quenched samples. The precipitates attained a maximum size (equatorial diameter) of ∼21 nm and ∼17 nm after 2 h and 4 h of ageing the water-quenched and air-cooled samples respectively. Although the air-cooled samples showed delayed nucleation in comparison to water-quenched sample, the volume fraction became approximately the same (∼11%) after ageing for 8 h. The average value of the activation energy for ω iso nucleation from the β-phase matrix was determined as 122 kJ mol −1 from electrical resistivity data using a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. The hardness increased with ageing time, with water quenching leading to a higher final value of hardness than air cooling.

KW - Electrical resistivity measurements

KW - Kinetics

KW - Small-angle neutron scattering

KW - Titanium alloys

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DO - 10.1016/j.jallcom.2020.157822

M3 - Article

SN - 0925-8388

VL - 859

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

M1 - 157822

ER -

Influence of cooling rate on the precipitation kinetics of nanoscale isothermal ω-phase in metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr

Abstract

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Keywords

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