The microstructure of as-melt spun Al-7%Si-0.3%Mg alloy and its variation in continuous heat treatment

Citation
M. Yan et al., The microstructure of as-melt spun Al-7%Si-0.3%Mg alloy and its variation in continuous heat treatment, MAT SCI E A, 284(1-2), 2000, pp. 77-83
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
ISSN journal
0921-5093 → ACNP
Volume
284
Issue
1-2
Year of publication
2000
Pages
77 - 83
Database
ISI
SICI code
0921-5093(20000531)284:1-2<77:TMOASA>2.0.ZU;2-P
Abstract
The commercial A356 alloy was treated using melt spinning at rotating speed s of 20 and 40 m s(-1), respectively. The as-melt spun ribbons were charact erized by a combination of optical microscopy (OPM), scanning electron micr oscopy (SEM): transmission electron microscopy (TEM) and X-ray diffraction (XRD). DSC tests were carried out to measure the microstructural evolution and melting of the ribbons during continuous heating, and microhardness of the ribbons under different conditions was also measured. It was found that at the chilling sides of A356 ribbons the matrix was composed of non-dendr itic equiaxed grains, while at free sides the matrix was composed of dendri tic grains. Silicon particles were found to preferentially precipitate alon g the grain boundaries on a nanometer scale at free sides. DSC tests indica ted that in A356 ribbons the endothermic peaks of ternary Al-Mg2Si-Si eutec tic melting drastically weakened, while the peaks of binary Al-Mg2Si eutect ic melting vanished. The microhardness of the aluminum matrix at chilling s ides of as-melt spun ribbons was significantly raised. Published by Elsevie r Science S.A.