Journal Article

IMPULSE-2026-00021

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Spatially resolved in situ defect spectroscopy during tensile tests using a scanning positron beam

Hugenschmidt, C. (Corresponding author)MLZ* ; Thalmayr, M. ; Gigl, T.

2025
Elsevier Amsterdam

Please use a persistent id in citations: doi:10.1016/j.physb.2025.417613

Abstract: We present a novel technique for analyzing materials in situ during tensile tests using a scanning positron microbeam. Doppler broadening spectroscopy (DBS) of the 511 keV annihilation line is used to measure the variation of the local defect concentration with a resolution of (FWHM). The evolution of the defect distribution during tensile tests is observed by recording two-dimensional (2D) defect maps as a function of stress and strain with an unprecedentedly short measurement time of 35 s per spectrum. We studied Al alloys (AlMg4.5Mn and Al99.5) at different stages of deformation in order to correlate the spatially resolved formation of lattice defects on an atomic level with the macroscopic material properties obtained by the recorded stress–strain curves. The onset of plastic deformation, i.e. the emergence of stress-induced defects, was clearly observed whereas elastic strain (Hook’s region) does not lead to changes in DBS spectra. Finally, observing the maximum local defect density enables prediction of the crack formation that is responsible for the specimen’s failure.

Keyword(s): Engineering, Industrial Materials and Processing (1st) ; Industrial Application (2nd) ; Instrument and Method Development (2nd)

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Contributing Institute(s):

1. NEPOMUC (NEPOMUC)

Experiment(s):

1. NEPOMUC: Neutron induced positron source munich (SR11)

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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