β' and β precipitation in an Al–Mg alloy studied by DSC and TEM
β' and β precipitation in an Al–Mg alloy studied by DSC and TEM
Precipitation in Al–16 at.%Mg is investigated by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The shape of the β' formation DSC effect is interpreted with a novel theory and the curves obtained on the basis of this new theory fit well to the experimental curves. The s parameter derived from these fits, which is akin to the Avrami parameter n appearing in the Johnson–Mehl–Avrami–Kolmogorov model, is larger than 2.5, indicating that β' precipitation is an autocatalytic process. TEM showed the abundant presence of defects (mostly dislocation loops) but no evidence of nucleation of β' precipitates on these defects. The enthalpies of formation of the β and β' phases are derived as 15.7 and 11.5 kJ per mol Mg, respectively.
aluminium alloys, precipitation (chemical), differential scanning calorimetry, transmission electron microscopy, Al-Mg, dislocations (crystals), nucleation, curve fitting, mathematical models, enthalpy, John-Mehl-Avrami-Kolmogorov model
3381-3397
Starink, M.J.
fe61a323-4e0c-49c7-91f0-4450e1ec1e51
Zahra, A.-M.
602ec757-47a9-47dc-9739-1ba7a0e0d3db
1998
Starink, M.J.
fe61a323-4e0c-49c7-91f0-4450e1ec1e51
Zahra, A.-M.
602ec757-47a9-47dc-9739-1ba7a0e0d3db
Starink, M.J. and Zahra, A.-M.
(1998)
β' and β precipitation in an Al–Mg alloy studied by DSC and TEM.
Acta Materialia, 46 (10), .
(doi:10.1016/S1359-6454(98)00053-6).
Abstract
Precipitation in Al–16 at.%Mg is investigated by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The shape of the β' formation DSC effect is interpreted with a novel theory and the curves obtained on the basis of this new theory fit well to the experimental curves. The s parameter derived from these fits, which is akin to the Avrami parameter n appearing in the Johnson–Mehl–Avrami–Kolmogorov model, is larger than 2.5, indicating that β' precipitation is an autocatalytic process. TEM showed the abundant presence of defects (mostly dislocation loops) but no evidence of nucleation of β' precipitates on these defects. The enthalpies of formation of the β and β' phases are derived as 15.7 and 11.5 kJ per mol Mg, respectively.
Text
Starink&Zahra Acta Mater 1998 Al-Mg.pdf
- Version of Record
Restricted to Registered users only
Request a copy
More information
Published date: 1998
Keywords:
aluminium alloys, precipitation (chemical), differential scanning calorimetry, transmission electron microscopy, Al-Mg, dislocations (crystals), nucleation, curve fitting, mathematical models, enthalpy, John-Mehl-Avrami-Kolmogorov model
Identifiers
Local EPrints ID: 41858
URI: http://eprints.soton.ac.uk/id/eprint/41858
ISSN: 1359-6454
PURE UUID: 7fca44f0-ece9-470a-af03-ba097f7ad108
Catalogue record
Date deposited: 12 Oct 2006
Last modified: 15 Mar 2024 08:38
Export record
Altmetrics
Contributors
Author:
A.-M. Zahra
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics