Mechanical properties and damping capacity of (SiCp+Al2O3•SiO2f)/Mg hybrid metal matrix composite

A new kind of metal matrix composite (MMC) with a matrix of pure magnesium and hybrid reinforcements of SiC particulates and Al2O3SiO2 (mullite) short fibers was fabricated, its mechanical property and damping capacity were studied. It was found that the strength of the magnesium matrix composites was improved strongly at the expense of its damping capacity compared with that of pure magnesium. Moreover, the two damping peaks in the relaxation model were firstly reported in this paper. Peak at about 150degreesC appeared not only in pure magnesium but also in its composites, which was related to dislocation movement; peak II at about 250degreesC appeared only in the Mg matrix composites, and was attributed to the interface slip between SiC particulate and Mg matrix. (C) 2004 Elsevier B.V. All rights reserved.