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:
Al-Fe compounds are usually present in the as-cast microstructure of Al-alloys as large needles orplates. As such, they have a detrimental effect on the mechanical properties of Al-alloys containingFe, either as an impurity element or as an alloying addition. However, Fe-containing Al-alloys alsooffer attractive physical properties, such as improved stiffness, wear resistance and thermalresistance. If the needle and plate morphology of the Al-Fe compounds can be modified to a morecompact morphology, with refined particle size and uniform distribution, the mechanical propertiesof Al-Fe based Al-alloys can be substantially improved, and therefore, they will find widerapplications in many engineering sectors. A new semisolid metal processing technology, rheodiecasting(RDC), has been developed for production of Al-alloy components with high integrity.The RDC process innovatively combines the dispersive mixing power of the twin-screwmechanism, for the creation of high quality semisolid slurry, with the high efficiency, low costnature of the high-pressure diecasting (HPDC) process for component shaping. In this paper, wepresent our experimental results on the effects of intensive melt shearing on the size andmorphology of Al-Fe compounds in A380 alloys, with different levels of Fe additions. Theexperimental results have shown that intensive melt shearing during solidification can effectivelychange the particle shape from the usual needles and plates, to an equiaxed morphology. Sampleswhich have undergone with melt shearing, exhibit much improved strength and ductility comparedto those with the same level of Fe addition, but without exposure to melt shearing
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.1251.pdf
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