Characterizing nanoscale precipitation in a titanium alloy by laser-assisted atom probe tomography

James Coakley*, Anna Radecka, David Dye, Paul A.J. Bagot, Tomas L. Martin, Ty J. Prosa, Yimeng Chen, Howard J. Stone, David N Seidman, Dieter Isheim

*Corresponding author for this work

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Atom-probe tomography was performed on the metastable β-Ti alloy, Ti-5Al-5Mo-5V-3Cr wt% (Ti-5553), aged at 300 °C for 0 to 8 h, to precipitate the embrittling isothermal ω phase. Accurate precipitate quantification requires monitoring and controlling suitable charge-state ratios in the mass spectrum, which in turn are closely related to the laser pulse energy used. High ultraviolet laser pulse energies result in significant complex molecular ion formation during field-evaporation, causing mass spectral peak overlaps that inherently complicate data analyses. Observations and accurate quantification of the ω-phase under such conditions are difficult. The effect is minimized or eliminated by using smaller laser pulse energies. With a small laser pulse energy, Ti-rich and solute depleted precipitates of the isothermal ω phase with an oxygen enriched interface are observed as early as after 1 h aging time utilizing the LEAP 5000X S (77% detection efficiency). We note that these precipitates were not detected below a 2 h aging time with the LEAP 4000X Si (58% detection efficiency). The results are compared to the archival literature. The Al concentration in the matrix/precipitate interfacial region increases during aging. Nucleation of the α-phase at longer aging times may be facilitated by the O and Al enrichment at the matrix/precipitate interface (both strong α-stabilisers). The kinetics and compositional trajectory of the ω-phase with aging time are quantified, facilitating direct correlation of the APT data to previously published mechanical testing.

Original languageEnglish (US)
Pages (from-to)129-138
Number of pages10
JournalMaterials Characterization
Volume141
DOIs
StatePublished - Jul 1 2018

Fingerprint

titanium alloys
Titanium alloys
Tomography
Precipitates
precipitates
tomography
Aging of materials
Atoms
Lasers
probes
Laser pulses
lasers
atoms
pulses
Ultraviolet lasers
energy
Mechanical testing
matrices
ultraviolet lasers
molecular ions

Keywords

  • Aging
  • Atom probe tomography
  • Precipitation
  • Titanium alloys
  • ω-Phase

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Coakley, James ; Radecka, Anna ; Dye, David ; Bagot, Paul A.J. ; Martin, Tomas L. ; Prosa, Ty J. ; Chen, Yimeng ; Stone, Howard J. ; Seidman, David N ; Isheim, Dieter. / Characterizing nanoscale precipitation in a titanium alloy by laser-assisted atom probe tomography. In: Materials Characterization. 2018 ; Vol. 141. pp. 129-138.
@article{8b9358e3baef4fccbf504145f4ef7d5f,
title = "Characterizing nanoscale precipitation in a titanium alloy by laser-assisted atom probe tomography",
abstract = "Atom-probe tomography was performed on the metastable β-Ti alloy, Ti-5Al-5Mo-5V-3Cr wt{\%} (Ti-5553), aged at 300 °C for 0 to 8 h, to precipitate the embrittling isothermal ω phase. Accurate precipitate quantification requires monitoring and controlling suitable charge-state ratios in the mass spectrum, which in turn are closely related to the laser pulse energy used. High ultraviolet laser pulse energies result in significant complex molecular ion formation during field-evaporation, causing mass spectral peak overlaps that inherently complicate data analyses. Observations and accurate quantification of the ω-phase under such conditions are difficult. The effect is minimized or eliminated by using smaller laser pulse energies. With a small laser pulse energy, Ti-rich and solute depleted precipitates of the isothermal ω phase with an oxygen enriched interface are observed as early as after 1 h aging time utilizing the LEAP 5000X S (77{\%} detection efficiency). We note that these precipitates were not detected below a 2 h aging time with the LEAP 4000X Si (58{\%} detection efficiency). The results are compared to the archival literature. The Al concentration in the matrix/precipitate interfacial region increases during aging. Nucleation of the α-phase at longer aging times may be facilitated by the O and Al enrichment at the matrix/precipitate interface (both strong α-stabilisers). The kinetics and compositional trajectory of the ω-phase with aging time are quantified, facilitating direct correlation of the APT data to previously published mechanical testing.",
keywords = "Aging, Atom probe tomography, Precipitation, Titanium alloys, ω-Phase",
author = "James Coakley and Anna Radecka and David Dye and Bagot, {Paul A.J.} and Martin, {Tomas L.} and Prosa, {Ty J.} and Yimeng Chen and Stone, {Howard J.} and Seidman, {David N} and Dieter Isheim",
year = "2018",
month = "7",
day = "1",
doi = "10.1016/j.matchar.2018.04.016",
language = "English (US)",
volume = "141",
pages = "129--138",
journal = "Materials Characterization",
issn = "1044-5803",
publisher = "Elsevier Inc.",

}

Characterizing nanoscale precipitation in a titanium alloy by laser-assisted atom probe tomography. / Coakley, James; Radecka, Anna; Dye, David; Bagot, Paul A.J.; Martin, Tomas L.; Prosa, Ty J.; Chen, Yimeng; Stone, Howard J.; Seidman, David N; Isheim, Dieter.

In: Materials Characterization, Vol. 141, 01.07.2018, p. 129-138.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Characterizing nanoscale precipitation in a titanium alloy by laser-assisted atom probe tomography

AU - Coakley, James

AU - Radecka, Anna

AU - Dye, David

AU - Bagot, Paul A.J.

AU - Martin, Tomas L.

AU - Prosa, Ty J.

AU - Chen, Yimeng

AU - Stone, Howard J.

AU - Seidman, David N

AU - Isheim, Dieter

PY - 2018/7/1

Y1 - 2018/7/1

N2 - Atom-probe tomography was performed on the metastable β-Ti alloy, Ti-5Al-5Mo-5V-3Cr wt% (Ti-5553), aged at 300 °C for 0 to 8 h, to precipitate the embrittling isothermal ω phase. Accurate precipitate quantification requires monitoring and controlling suitable charge-state ratios in the mass spectrum, which in turn are closely related to the laser pulse energy used. High ultraviolet laser pulse energies result in significant complex molecular ion formation during field-evaporation, causing mass spectral peak overlaps that inherently complicate data analyses. Observations and accurate quantification of the ω-phase under such conditions are difficult. The effect is minimized or eliminated by using smaller laser pulse energies. With a small laser pulse energy, Ti-rich and solute depleted precipitates of the isothermal ω phase with an oxygen enriched interface are observed as early as after 1 h aging time utilizing the LEAP 5000X S (77% detection efficiency). We note that these precipitates were not detected below a 2 h aging time with the LEAP 4000X Si (58% detection efficiency). The results are compared to the archival literature. The Al concentration in the matrix/precipitate interfacial region increases during aging. Nucleation of the α-phase at longer aging times may be facilitated by the O and Al enrichment at the matrix/precipitate interface (both strong α-stabilisers). The kinetics and compositional trajectory of the ω-phase with aging time are quantified, facilitating direct correlation of the APT data to previously published mechanical testing.

AB - Atom-probe tomography was performed on the metastable β-Ti alloy, Ti-5Al-5Mo-5V-3Cr wt% (Ti-5553), aged at 300 °C for 0 to 8 h, to precipitate the embrittling isothermal ω phase. Accurate precipitate quantification requires monitoring and controlling suitable charge-state ratios in the mass spectrum, which in turn are closely related to the laser pulse energy used. High ultraviolet laser pulse energies result in significant complex molecular ion formation during field-evaporation, causing mass spectral peak overlaps that inherently complicate data analyses. Observations and accurate quantification of the ω-phase under such conditions are difficult. The effect is minimized or eliminated by using smaller laser pulse energies. With a small laser pulse energy, Ti-rich and solute depleted precipitates of the isothermal ω phase with an oxygen enriched interface are observed as early as after 1 h aging time utilizing the LEAP 5000X S (77% detection efficiency). We note that these precipitates were not detected below a 2 h aging time with the LEAP 4000X Si (58% detection efficiency). The results are compared to the archival literature. The Al concentration in the matrix/precipitate interfacial region increases during aging. Nucleation of the α-phase at longer aging times may be facilitated by the O and Al enrichment at the matrix/precipitate interface (both strong α-stabilisers). The kinetics and compositional trajectory of the ω-phase with aging time are quantified, facilitating direct correlation of the APT data to previously published mechanical testing.

KW - Aging

KW - Atom probe tomography

KW - Precipitation

KW - Titanium alloys

KW - ω-Phase

UR - http://www.scopus.com/inward/record.url?scp=85046369694&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85046369694&partnerID=8YFLogxK

U2 - 10.1016/j.matchar.2018.04.016

DO - 10.1016/j.matchar.2018.04.016

M3 - Article

VL - 141

SP - 129

EP - 138

JO - Materials Characterization

JF - Materials Characterization

SN - 1044-5803

ER -