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:
The oxide layer that usually covers the surface of liquid aluminum and its alloys, is oneof the main factors that hinders infiltration of these alloys into graphite particle compacts. Theoxide film increases the threshold pressure for infiltration and the porosity of the resultingcomposites is large because the wetting at the metal/carbon interface is reduced. Infiltratinggraphite compacts with tin requires, however, a much lower pressure, less than half of that requiredto infiltrate the eutectic Al-12Si alloy. As the surface tension of tin is half that of the Al-12Si alloy,this result indicates that wetting at the Sn/C interface is slightly better. As a result, porosity in theinfiltrated samples is reduced. In order to reduce the threshold pressure and improve the propertiesof Al-Si/graphite composites, a novel method has been used in this work that consists in placing athin film of tin at the compact end through which infiltration takes place. During the infiltrationprocess the graphite particles are firstly infiltrated by tin, which is pushed by the aluminum alloy,thus avoiding the oxidation of the latter. The method proved to be very effective in reducing thethreshold pressure, while keeping almost constant the infiltration rate
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.785.pdf
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