Characterization of defect microstructure in MgRE (RE=Ce, Nd) alloys after processing by high-pressure torsion using positron annihilation spectroscopy and a high resolution X-ray diffraction

Authors: Bibimoune, I., Bourezg, Y.I., Abib, K., Liedke, M.O., Wagner, A., Matej, Z., Huang, Y., Langdon, T.G. and Bradai, D.

Journal: Physica B: Condensed Matter

Volume: 663

ISSN: 0921-4526

DOI: 10.1016/j.physb.2023.414963

Abstract:

Two MgRE (RE = Ce, Nd) alloys with ultrafine-grain (UFG) microstructures were prepared by high-pressure torsion (HPT) at room temperature. The in-depth distribution of defects was characterized by Doppler broadening –variable energy positron annihilation spectroscopy (DB-VEPAS). The characteristic S parameter increases in bulk after HPT processing relative to an as-received sample and shows a relative stability between ½ and 10 turns, which suggests a rise in the open volume defect density. However, a theoretical analysis of the S(E) depth profile reveals an increase in the positron diffusion length from ∼115 nm for the as-received state to ∼207 nm after 10 HPT turns. Almost all the open volume defect consisted of dislocations (positron lifetime of τ = 260 ps). The dislocation density deduced from high-resolution X-ray diffraction in the HPT disc radial direction was reasonably homogeneous (around 4–6 × 1014 m−2).

https://eprints.bournemouth.ac.uk/38539/

Source: Scopus

Characterization of defect microstructure in MgRE (RE=Ce, Nd) alloys after processing by high-pressure torsion using positron annihilation spectroscopy and a high resolution X-ray diffraction

Authors: Bibimoune, I., Bourezg, Y.I., Abib, K., Liedke, M.O., Wagner, A., Matej, Z., Huang, Y., Langdon, T.G. and Bradai, D.

Journal: PHYSICA B-CONDENSED MATTER

Volume: 663

eISSN: 1873-2135

ISSN: 0921-4526

DOI: 10.1016/j.physb.2023.414963

https://eprints.bournemouth.ac.uk/38539/

Source: Web of Science (Lite)

Characterization of defect microstructure in MgRE (RE=Ce, Nd) alloys after processing by High-Pressure Torsion using Positron Annihilation Spectroscopy and a High Resolution X-ray Diffraction

Authors: Bibimoune, I., Bourezg, Y.I., Abib, K., Liedke, M.O., Wagner, A., Matej, Z., Huang, Y., Langdon, T.G. and Bradai, D.

Journal: Physica B: Condensed Matter

Volume: 663

Pages: 414963(1)-414963(8)

Publisher: Elsevier

ISSN: 0921-4526

DOI: 10.1016/j.physb.2023.414963

Abstract:

Two MgRE (RE=Ce, Nd) alloys with ultrafine-grain (UFG) microstructures were prepared by high-pressure torsion (HPT) at room temperature. The in-depth distribution of defects was characterized by Doppler broadening –variable energy positron annihilation spectroscopy (DBVEPAS). The characteristic S parameter increases in bulk after HPT processing relative to an as-received sample and shows a relative stability between ½ and 10 turns, which suggests a rise in the open volume defect density. However, a theoretical analysis of the S(E) depth profile reveals an increase in the positron diffusion length from ~115 nm for the as-received state to ~207 nm after 10 HPT turns. Almost all the open volume defect consisted of dislocations (positron lifetime of τ = 260 ps). The dislocation density deduced from high-resolution X-ray diffraction in the HPT disc radial direction was reasonably homogeneous (around 4-6 ×1014 m-2).

https://eprints.bournemouth.ac.uk/38539/

Source: Manual

Preferred by: Yi Huang

Characterization of defect microstructure in MgRE (RE=Ce, Nd) alloys after processing by High-Pressure Torsion using Positron Annihilation Spectroscopy and a High Resolution X-ray Diffraction

Authors: Bibimoune, I., Bourezg, Y.I., Abib, K., Liedke, M.O., Wagner, A., Matej, Z., Huang, Y., Langdon, T.G. and Bradai, D.

Journal: Physica B: Condensed Matter

Publisher: Elsevier

ISSN: 0921-4526

Abstract:

Two MgRE (RE=Ce, Nd) alloys with ultrafine-grain (UFG) microstructures were prepared by high-pressure torsion (HPT) at room temperature. The in-depth distribution of defects was characterized by Doppler broadening –variable energy positron annihilation spectroscopy (DBVEPAS). The characteristic S parameter increases in bulk after HPT processing relative to an as-received sample and shows a relative stability between ½ and 10 turns, which suggests a rise in the open volume defect density. However, a theoretical analysis of the S(E) depth profile reveals an increase in the positron diffusion length from ~115 nm for the as-received state to ~207 nm after 10 HPT turns. Almost all the open volume defect consisted of dislocations (positron lifetime of τ = 260 ps). The dislocation density deduced from high-resolution X-ray diffraction in the HPT disc radial direction was reasonably homogeneous (around 4-6 ×1014 m-2).

https://eprints.bournemouth.ac.uk/38539/

Source: BURO EPrints