Preageing of magnesium alloys

Certain magnesium alloy systems can obtain superior mechanical strength through age hardening. However, conventional ageing heat treatments for these alloys are rarely more complex than a single isothermal hold – especially when compared to those of aluminium alloys – so age hardenable magnesium all...

Full description

Saved in:
Bibliographic Details
Published in:Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2021-03, Vol.809, p.141002, Article 141002
Main Authors: Davis, A.E., Kennedy, J.R., Lunt, D., Guo, J., Strong, D., Robson, J.D.
Format: Article
Language:English
Subjects:
Age hardening
Aging
Aging (artificial)
Alloy development
Alloy systems
Aluminum base alloys
Deformation
Hardenability
Heat treatment
Magnesium alloys
Magnesium base alloys
Morphology
Nucleation
Precipitation
Precipitation hardening
Strengthening
Thermomechanical treatment
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:Certain magnesium alloy systems can obtain superior mechanical strength through age hardening. However, conventional ageing heat treatments for these alloys are rarely more complex than a single isothermal hold – especially when compared to those of aluminium alloys – so age hardenable magnesium alloys may not be achieving their full strengthening potential. The use of preageing, where a lower temperature heat treatment is utilised before a hotter secondary ageing step, has proven successful in boosting the strength of magnesium alloys previously, but these trials are few in number, and the testing conditions are limited. In this work, a wide range of preageing temperatures and times were trialled on commercial and experimental magnesium alloys to determine the effectiveness of the strengthening technique. The results showed that preageing can produce a significant boost in hardness, can reduce total ageing times, and can provide a degree of mechanical property customisation through control of precipitate habit plane and morphology. However, the effectiveness of the technique is alloy-system dependent, where the fundamental precipitate nucleation and phase evolution is a key contributor to the success of preageing; as is the energy barrier to nucleation in an alloy system, whether that be controlled by alloy chemistry or thermomechanical processing. The results are discussed in the context of alloy design and industrial processing.
ISSN:0921-5093
1873-4936
DOI:10.1016/j.msea.2021.141002