ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Closed-loop recycling should be promoted for wrought aluminum alloy scraps includingimpurity iron in order to use natural resources effectively. Fabrication of the alloy strip using a highrate of cooling is a promising method for reducing the detrimental effects of impurity iron. In thepresent study, strips of A6022 aluminum alloy with various Fe contents of up to 1.5 mass% werefabricated by a vertical-type, high-speed, twin-roll caster. The caster used in the study was equippedwith a pair of water-cooled, pure copper rolls, and a cooling slope upstream of the rolls. The stripsexhibited a common microstructural feature. Columnar grains grew from both surfaces of the strip,and they were gradually replaced by equiaxed grains. In the mid-central region, a band of fine grainswas observed. Such fine grains seemed to originate from the crystallized α-Al dendrites on thecooling slope or the roll surfaces. Internal cracks were observed in the A6022 alloy strip that wassubjected to the highest cooling rate. The cracks were located between equiaxed grains and finegrains at the mid-central region. The cracks were reduced with increasing Fe content. No cracks wereobserved for the alloy strips with 1.0 mass% Fe or greater. It was found that both a slight reduction inthe cooling rate and addition of Fe were effective for obtaining sound A6022 strips
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.1821.pdf
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