Microstructure and properties of functionally graded Al-Mg-B composites fabricated by centrifugal casting

The microstructure and tribological performance of compositionally and functionally graded Al-Mg/AlB2 metal-matrix composites (MMCs) produced try centrifugal casting have been investigated using Al-2wt.%Mg alloys containing 1, 2, 3, and 4 wt.% boron. Significant enrichment of aluminum diboride particles was observed in the external zone of the casting in the radial direction of the centrifugal caster. A corresponding increase in surface hardness as well as smaller wear volume in pin-on-disk wear tests were observed. The process provides a viable approach for lightweight, high wear resistance aluminum alloy components, particularly those with axial geometries. (C) 2008 Elsevier Ltd. All rights reserved.