Influence of second phase particles on the mechanical properties of a high solute Al-Zn-Mg alloy fabricated through laser powder bed fusion

•The correlation between second phase particles and mechanical properties of high solute Al-14Zn-3Mg prepared by laser powder bed fusion (LPBF) was investigated.•In-situ TEM of as-LPBF Al-14Zn-3Mg at 400 °C revealed the formation of T-phase (Mg32(Zn, Al)49) particles which was detrimental to ductili...

Full description

Saved in:
Bibliographic Details
Published in:Journal of alloys and compounds 2022-03, Vol.897, p.162958, Article 162958
Main Authors: Babu, A.P., Lam, M.C., Ma, J., Huang, A., Birbilis, N.
Format: Article
Language:English
Subjects:
Additive manufacturing
Aluminium
Aluminum base alloys
CALPHAD
Heat treating
Heat treatment
In-situ TEM
Magnesium
Mechanical properties
Phase diagrams
Phase transitions
Powder beds
Precipitates
Quasicrystal
T-phase
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•The correlation between second phase particles and mechanical properties of high solute Al-14Zn-3Mg prepared by laser powder bed fusion (LPBF) was investigated.•In-situ TEM of as-LPBF Al-14Zn-3Mg at 400 °C revealed the formation of T-phase (Mg32(Zn, Al)49) particles which was detrimental to ductility.•CALPHAD modelling revealed low interprecipitate spacing and high volume fraction of second phase particles in Al-14Zn-3Mg when compared to wrought Al-alloys. A high solute 7xxx series aluminium alloy, Al-14Zn-3Mg (in wt%), was prepared using laser powder bed fusion (LPBF). To provide an insight into the correlation of second phase particles and mechanical properties, several heat treatment conditions were modelled with CALPHAD, and phase transformations were realised through in-situ characterisation techniques. It was revealed that the formation of T-phase (Mg32(Zn, Al)49) at 400 °C contributed to loss of ductility from the direct heat treatment of as-LPBF Al-14Zn-3Mg. However, the improvement in hardness of solutionised and peak aged Al-14Zn-3Mg was attributed to the formation of high volume fraction of η’ and η (MgZn2) precipitates with low inter-precipitate spacing.
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2021.162958