Journal Article

IMPULSE-2026-00022

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Copper Precipitation in Aluminum Alloys Observed by Coincidence Doppler-Broadening Spectroscopy and Positron Annihilation Lifetime Spectroscopy

Mathes, L. (Corresponding author)MLZ* ; Suhr, M.MLZ* ; Heinl, L. ; Hirschmann, E. ; Liedke, M. O. ; Butterling, M. ; Hugenschmidt, C.MLZ*

2025
IOP Publ. Bristol

Please use a persistent id in citations: doi:10.1088/1742-6596/3149/1/012015

Abstract: The Cu content in Al alloys significantly influences the solidification and precipitation microstructure, which is crucial for tailoring material properties in aerospace and automotive engineering applications. Cu additions affect mechanical strength, corrosion resistance, and thermal stability by promoting the formation of precipitates during artificial aging [1]. Positron annihilation spectroscopy (PAS), in particular coincidence Doppler-broadening spectroscopy (CDBS), is a powerful tool for investigating Cu precipitation in Al alloys [2, 3], as positrons are highly sensitive to vacancy-like defects and reveal information about the local chemical surroundings. Moreover, due to the high positron affinity of Cu, thermalized positrons become efficiently trapped in Cu precipitates. CDBS provides background-suppressed momentum-resolved information about the annihilation site. The shape of the 511 keV annihilation peak and its high-momentum region reflect the presence of high-Z elements like Cu in Al. In this study we present CDBS and positron annihilation lifetime spectroscopy measurements of pure Cu, high-purity AlCu alloys with 1, 2, and 3 wt.% Cu, and a commercial-purity AlCuMg alloy containing 3.5–4.5 wt.% Cu. The samples have been T4-treated for Cu precipitation, i.e., GP(I)-zone formation. Our findings show a change in the annihilation site with increasing Cu content and demonstrate the suitability of PAS for analyzing Cu precipitation in Al, offering valuable insights for alloy development and thermal treatment optimization.

Keyword(s): Engineering, Industrial Materials and Processing (1st) ; Condensed Matter Physics (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:
; Nationallizenz ; SCOPUS

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