Two types of S phase precipitates in Al-Cu-Mg alloys
Two types of S phase precipitates in Al-Cu-Mg alloys
Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) have been used to study S phase precipitation in an Al-4.2Cu-1.5Mg-0.6Mn-0.5Si (AA2024) and an Al-4.2Cu-1.5Mg-0.6Mn-0.08Si (AA2324) (wt-%) alloy. In DSC experiments on as solution treated samples two distinct exothermic peaks are observed in the range 250 to 350°C, whereas only one peak is observed in solution treated and subsequently stretched or cold worked samples. Samples heated to 270°C and 400°C at a rate of 10°C/min in the DSC have been studied by TEM. The selected area diffraction patterns show that S phase precipitates with the classic orientation relationship form during the lower temperature peak, and for the solution treated samples, the higher temperature peak is caused by the formation of a second type of S phase precipitates which have an orientation relationship that is rotated by ~4 degrees to the classic one. The effects of Si and cold work on the formation of second type of S precipitates have been discussed.
S precipitate, Al-Cu-Mg alloy, TEM, DSC, orientation relationship, transformation
933-941
Wang, S.C.
8a390e2d-6552-4c7c-a88f-25bf9d6986a6
Starink, M.J.
fe61a323-4e0c-49c7-91f0-4450e1ec1e51
February 2007
Wang, S.C.
8a390e2d-6552-4c7c-a88f-25bf9d6986a6
Starink, M.J.
fe61a323-4e0c-49c7-91f0-4450e1ec1e51
Abstract
Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) have been used to study S phase precipitation in an Al-4.2Cu-1.5Mg-0.6Mn-0.5Si (AA2024) and an Al-4.2Cu-1.5Mg-0.6Mn-0.08Si (AA2324) (wt-%) alloy. In DSC experiments on as solution treated samples two distinct exothermic peaks are observed in the range 250 to 350°C, whereas only one peak is observed in solution treated and subsequently stretched or cold worked samples. Samples heated to 270°C and 400°C at a rate of 10°C/min in the DSC have been studied by TEM. The selected area diffraction patterns show that S phase precipitates with the classic orientation relationship form during the lower temperature peak, and for the solution treated samples, the higher temperature peak is caused by the formation of a second type of S phase precipitates which have an orientation relationship that is rotated by ~4 degrees to the classic one. The effects of Si and cold work on the formation of second type of S precipitates have been discussed.
Text
proof-SCW1.pdf
- Accepted Manuscript
More information
Published date: February 2007
Keywords:
S precipitate, Al-Cu-Mg alloy, TEM, DSC, orientation relationship, transformation
Organisations:
Engineering Mats & Surface Engineerg Gp
Identifiers
Local EPrints ID: 41409
URI: http://eprints.soton.ac.uk/id/eprint/41409
ISSN: 1359-6454
PURE UUID: c70e50bb-2d35-44ce-ae01-8b07f6cf64b2
Catalogue record
Date deposited: 07 Sep 2006
Last modified: 15 Mar 2024 08:29
Export record
Altmetrics
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