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Research Article
ScienceAsia 30 (2004): 25-31 |doi: 10.2306/scienceasia1513-1874.2004.30.025
Microstructure-Processing-Property-Relationship
of Rapidly Solidified Al-Fe-(V, Si) Alloys
Ruangdaj Tongsri,a,* Jane Minay,b Richard Thackray,b Richard Dashwoodb and Henry Mcshaneb
ABSTRACT: Gas-atomised powders of Al-Fe-(V, Si) alloys exhibited microstructures consisting of several forms
of icosahedral phase distributed in either supersaturated solid solution of α-Al matrix, or in intercellular/
dendritic regions depending on powder particle size. During processing of the powders by hot extrusion, the
icosahedral phase particles transformed to more stable phase particles. Microstructures of extrudates produced
from fine Al-Fe-V powder particles showed homogeneous precipitation of ultrafine needle-like particles in
grains and at grain boundaries. This type of microstructure yielded high compressive strengths at room and
elevated temperatures. In microstructures of extrudates produced from coarse Al-Fe-V powder particles,
ultrafine needle-like particles were observed to coexist with globular particles. Because of large-size globular
particles, low compressive strengths at room and elevated temperatures of the extrudates produced from
coarse Al-Fe-V powder particles were obtained. The extrudates produced from fine Al-Fe-V-Si powder particles
showed microstructures with homogeneous precipitation of spherical-like particles. In contrast, the extrudates
produced from coarse Al-Fe-V-Si powder particles resulted in inhomogeneous microstructures, which were
attributed to banded structures or donut-shaped aggregates of spherical-like particles. Because of
inhomogeneous microstructures, low compressive strengths of the extrudates at room and elevated
temperatures were obtained.
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a National Metal and Materials Technology Center (MTEC), Thailand Science Park, 114 Paholyothin Rd., Klong 1, Klong Luang, Patumthani 12120 Thailand.
b Department of Materials, Imperial College of Science, Technology and Medicine, Prince Consort Rd., London SW7 2 BP, UK.
* Corresponding author, E-mail: ruangdt@mtec.or.th
Received 23 May 2003,
Accepted 24 Dec 2003
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